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Showing content with the highest reputation since 04/05/20 in Posts

  1. 40 points
    The rhyming was completely unintentional! However, I feel like I've processed this to death by now! A very tricky target, where pulling detail from one region can mean overdoing another. I've left it with a more "ethereal" and glowing look, rather than chasing after the intricate detail that is no doubt present there. Maybe I'll come back to it later at some point. Equipment: Atik 490EX Atik EFW2 Chroma LRGB filters Atik OAG Primaluce Lab Esatto 2” Robotic Focuser Celestron Edge HD 8" Celestron 0.7x Reducer for Edge HD 8" Avalon M-Uno Pegasus Ultimate Powerbox Intel NUC Mini PC L: 600 x 60s = 10 hours R: 130 x 120s = 4 hours 20 mins G: 130 x 120s = 4 hours 20 mins B: 130 x 120s = 4 hours 20 mins Dark, flat and bias frames applied Processed in AstroPixelProcessor & Pixinsight Bortle 5 skies Major credit to APP for processing the data from multiple nights in a painless workflow without skipping a beat!
  2. 34 points
    Samyang 135mm F2 lens, but I stopped it down to F2.8 Atik460EX and Baader filters on HEQ5 Ha 900 x 8 & Ha 600 X 9 total Ha 3 1/2 hours Oiii 9 x 300 binned (45m) Sii 8 x 300 binned (40m) Hubble Palette + RGB (for the stars) 12 x 200 each NOT binned. Total 2 hours Cloud stopped play on the 2nd night or would have got more Oiii and Sii. Total imaging time (over 2 nights) 6h 55mins or 7 hours as near as damn it. Bortle 8
  3. 31 points
    Hi. I purchased a second hand 12" meade ACF a couple of months ago. Due to the bad weather I didn't have the chance to try it until last week. The moon was so amazing that I had to fetch my old asi120m and take some pictures. Here is the result. Thanks for looking
  4. 26 points
    Wanted to get double this data but ran out of clear skies: Taken over 2 nights March 2020 from Bortle 8Samyang 135mm F2 lens stopped down to F2.8Atik460EX and Baader filtersHEQ5Ha 2 x 600secs + 6 x 900secsOiii 6 x 300secs binned + 3 x 600 unbinnedRGB 3 x 150 (each)Total imaging time 2hours 55mins (almost 3 hours)
  5. 26 points
    Ha and OIII combined HOO > RGB. Processed in PixInsight and GIMP. 2h Ha plus 2h OIII integration time captured concurrently on my dual imaging rig. ASI1600MM-Cool cameras set to unity gain, Astrodon 3nm NB filters and Asahi (Pentax) SuperMultiCoated Takumar 200mm f4 lenses.
  6. 25 points
    Hi, My last photo, ~19h exp SHO, TS APO100Q, QHY695A, Ioptron CEM60EC, chroma filters. full at my Astrobin https://www.astrobin.com/zekq99/?nc=user Can You find PN G086.2-01.2 ?
  7. 25 points
    I've been struggling with coarse grain on my ASI174 all day! So don't kill the messenger!
  8. 24 points
    Hi all, I can't believe i even got an image given the conditions for rgb imaging. No astro dark, quite a low target and an average 70% moon over the two nights. I just recently set about collimating the Epsilon and i think the increased sharpness from decent collimation shows. It's still off in the upper corners so more tweaking required. I wonder is it tilt i'm looking at or spacing. So this is 5 hrs gathered over the last two nights 100*180 second subs with the Asi2600mc through a Takahashi Epsilon 130 Mounted on an AZEQ6 Sequence generator pro for the image acquisition. Processed in APP, PI, and PS Richard. .png .jpg
  9. 24 points
    M57 – The Ring Nebula (NGC 6720) Introduction I don’t know what it is about this object but finding it visually with a manual telescope has always proved to be a bit of a challenge for me! I don’t know if it is simply that it is so relatively small or what but I am always grateful for a GoTo mount when I am seeking it out. Visually it looks like a tiny smoke ring hanging in deep space but train a camera on it and it really comes alive. This gorgeous object was discovered in 1779 by the French astronomer Antoine Darquier de Pellepoix in the constellation of Lyra. However, there is some dispute over this as Charles Messier wrote in his observations earlier in the same year that he had noticed a ‘small patch of light’ near the path of Bode's comet and it believed that this was the nebula Typical of many planetary nebulae, M57 responds well to both broadband and narrowband imaging but my goal here was to bring out some of its outer halo and for that, the weapons of choice are in the narrowband domain. The nebula lies at a distance of approximately 2,250 light years from Earth and has an apparent visual magnitude of +8.8 h. The white dwarf at its core has a magnitude of +15.8 but this is not always visible in narrowband images. Image Stats Mount: Mesu 200 Telescope: Sky-Watcher Esprit 150 Flattener: Sky-Watcher Esprit specific Camera: QSI 683 WSG-8 Filters: Astrodon 3nm Ha, 3nm OIII Subframes: 30 x 1800 sec Ha, 16 x 1800 sec OIII Total Integration: 23 hours Control: CCD Commander Capture: MaxIm DL Calibration, Stacking and Deconvolution: PixInsight Post-Processing: PhotoShop PS3 Location Constellation Lyra RA 18° 54' 21.0" DEC +33° 03' 18.0" Distance ~2250ly
  10. 24 points
    26 x 5 min exposure. Still loving my little 550d DSLR
  11. 24 points
    I had the opportunity to borrow a monochrome camera to do the tests I always wanted on the Moon.Below are the first results for colleagues to analyze.I realized from the outset the advantage of mono cameras for specific wavelengths since I normally use an ASI290MC to do all my captures. This is mainly explained by the fact that, without the layer matrix, a monochrome camera uses 100% of its pixels to perform the capture, while a color camera would use only 25% to capture on the IR 685 which was the filter used.Despite everything, due to the great fluctuation of my seeing, varying in a matter of a few minutes, I do not discard the advantages of a color camera for color captures, since while a mono camera would make only 1 film I can make at least about 4 with the colored one. This greatly increases the chance of catching a brief favorable moment that can save an entire section of photography.Moon on May 4, 2020.C14 Edge + ASI 178MM + IR pass 685Total of 2000 frames per photo with 350 stacking.
  12. 23 points
    This is a reprocess of old data using a star reduction technique I hadn't encountered at the time I did the original. Obviously we're in the thick of the Milky Way here and holding down the stars to let the nebulae do the talking is tricky. The image is HaLRGB from the Tak FSQ106N and full frame Atik 11000 (still my favourite camera...) Both nebulae were enhanced by applying higher resolution data from the TEC140. All I did was remove the stars entirely from a copy and then replace them with the originals at only partial opacity in blend mode lighten. Very easy indeed and, for the first time, I'm happy with this one. Mount, as ever, was a Mesu 200. Olly
  13. 23 points
    Taken over 3 nights as it was late rising over the house tops with little Astro darkness. Atik460EX and Samyang 135mm F2 lens @ F2.8HEQ5Ha 4 x 900Ha 15 x 600Oiii 10 x 300 binnedSii 12 x 300x2RGB stars 6 x 150 (eachTotal of 6 hours 5mins
  14. 23 points
    Completely ridiculous, clear skies every night, keep giggling like a kid with candy. Tuesday night 26th May. Did a load of homework on Stellarium and the star charts (I need both) and I do the usual optimist route. Time will tell. Set up the EQ5 with the 150 pds in bright sunlight. Not a single cloud and I grab the bins and the dogs and walk to the top of the lane to observe Venus and hopefully for the second time Mercury. Venus against the bright sundown ‘amazing’ quarter illuminated disk, like a distant mimic of the moon. I had to wait till 23:00hrs till it was dark enough to do any EP work. Sat back in the chair watching space junk tumble and flash across the sky! Would make an amazing AP trail. First up M13 just to test alignment. I have spent a lot f time on this recently so for me no need to dwell. Next Glob M 92, I prefer this in the EP to M13. Appears to have a tighter brighter core. It’s outer area seems to do a similar thing to Andromeda. Focus on the core but there seems to be much more. Heading over to NGC 6210 Turtle Nebula still in Hercules. Should be beyond my mag limit of tenish. Surface brightness made me say “why not”. First look, three stars, nothing else. Hooded up and the lower star is not sharp. More an out of focus blob, with a light blue green colour. Soooo small. First for me! Then a meteor shoots through the fov, amazing. Into Draco. NGC 5985/ 5981/5982 Draco’s Trio. Absolutely nothing! I have been doing so well but the brightest at mag 12 was going to be a stretch. M102. I would normally talk about this, but I noticed in the charts a nearby edge on galaxy NGC 5907. Gob smacked, better than 102, I have that ear marked for an AP session. Into Lyra. Quite low on my horizon for the time, just after midnight. Would be rude note to look at the Ring Nebula M57. Just want to say that when I do EP sessions I use the voice recorder on my phone. Listening back to record my notes I have the following... Who ever first saw that through a scope must have wondered how there is a polo mint in space. Completely forgot NGC 6543 The Cats Eye Nebula so back to Draco. Nice Crisp Blue Ball. Larger than Turtle. Over to Cygnus. So many open clusters! I am sorry to say that I am underwhelmed by OC’s. Getting close to bed time now so a chance at the Eastern Veil. NO CHANCE, way to low to my horizon. If I could only stay out all night. Now to unfinished business. The Blinking Planetary! For a planetary a bit bigger than I was expecting. White in colour, but could not discern any blinking. Must look into that. Ended with a chancers look at M83 in Hydra. I am 103/110 of Messier’s list. Now 104/110. Very low to the horizon but no averted vision needed. Wishing you all clear skies and the opportunity that I have just had. Marvin
  15. 23 points
    Interesting and fun shootout from Astrobiscuit here. I’m not an imager at all but still enjoyed it. Perhaps some hope and inspiration for budget restricted aspiring astrophotographers?
  16. 23 points
    Had a fantastic night tonight! I think it must be coming up for my first anniversary- I remember last year waiting up till 2am to see Jupiter for the first time through my new Tal-1 and I’ve just seen Jupiter rising at 2am again After the wonder that was Orion disappeared into the west there was a period where I’d look up and not see much- nothing familiar or exciting- skies too poor for galaxies- just a few doubles really- oh and Venus of course. Then Vega appeared, and Cygnus and now the planets are coming! So I spent this evening revisiting and welcoming back old familiar friends with my fullerscope dob- the double double, the ring, the dumbbell (not surprised I couldn’t find it with the telementor the other night- it was very faint), spent a good long while on beautiful m13 which took me so long to find last year. Had a quick look for the veil with an oiii but didn’t see anything- didn’t really expect to though. Albireo was beautiful as ever. The real highlight though was some great success with some close doubles. Once the scope had settled I was able to split Izar with my 14mm- about 114x and with my 3.5 it was a huge split! Oh and the colours! Beautiful! On to Zeta Hercules- I’ve tried a few times without success but I’m pretty sure I got it this time. I may have missed it before as I didn’t realise but believe the b star is much smaller than the A- want to check with @John if the b star trails A as they move across the fov? It was a very tight split with the 3.5 but I’m pretty sure I got it. Next up Pi Aquilae- one of @Stu ‘s favourites I think- he certainly mentioned it a few times last year and as a result I tried many times- so many times without success to split it. Well tonight I did! A clean split but very tight- a similar sized looking pair. What a relief! I also had a look at Iota Cass which eluded the telementor but was almost visible as a triplet in my 20 and a clean split at higher powers- a very attractive little grouping. Finally Antares was a no show- no surprise there... Despite the clear sky and it seeming reasonably clear of the horizon it remained as always a blurry set of traffic lights with red at the top and a greeny yellow below. I don’t know if that’s just atmospheric aberration or if it’s almost splitting but I really hope to see that split one day this year! Jupiter rose as I was packing up- I had a quick look but it needed more time- the disk showed no detail but the moons were bright and the apparition an exciting foretaste of things to come. Saturn was behind trees- I could just peek a glimpse. Had I not had numb fingers and toes and a very hungry belly I’d have stayed up another hour to see them in their full glory but that’ll have to wait another evening. I think the combination of the clearer covid skies and the improvements I’ve made to the scope made for a really enjoyable and productive, if a bit nippy, evening. Awesome!
  17. 23 points
    Hi. I started this in early December and completed the final panel in late February. I made the mistake of thinking that 3 hours per panel would be sufficient. If i were to start again i would push that to at least 5. Noise was a big issue here with all that feint dust but i feel i just about made it work. Stacked and combined in APP Processed in APP, PI and PS. 5 panels were with the Asi 071 and the final upper right corner panel was completed using the Asi2600. All captured using my Esprit 100 mounted on an AzEq6. Subs were of 150 second duration for a total imaging time of 18hrs Richard
  18. 22 points
    Hi All Here is my first astrophotography image ever. Could I get some advice on what to improve next time. Rig: Skywatcher Eq6-r pro Skywatcher f/4 8" Carbon quatro Skywatcher Aplanatic CC Zwo asi 294 pro Image: 240 lights 30sec gain medium 20 darks 30 flats Post: Gimp exposure, levels, curves, saturation PS saturation, gradient removed Thanks for your advice Thomas
  19. 21 points
    In my previous post I observed that my data for M13 could do with a bit more processing to make it 'sparkle' more. I adjusted the original RGB image as a colour layer, slightly increasing the saturation and softening it a bit as some yellow stars had become a bit posterised on close inspection. I went back to the original data and reprocess it it with a lot more effort on brining out faint stars while not blowing out the core. Then I applied some very gentle lucy-richardson deconvolution, basically kernel size and kurtosis set on 1 except strength at just 0.7. This was enough to make the stars in the core more prominent and lift up the fainter outer ones. Although this was now a nice RGB image, the colour wasn't as good as the original so I combined them with the new image as a 92% luminance layer. Finally I slightly blurred the cores of the two big stars to tone them down a touch.
  20. 21 points
    Morning all. I'm still buzzing from the last 3 hours fun. I've been observing with binoculars for years, but tonight was the first night with my new 8" dob (Bresser), and it went so much better than I expected. Bearing in mind that in Edinburgh now, astronomical twilight is the best I can get. It's Bortle-6 here too, with some nearby streetlights and railway yards to the south, with lots of spotlights. Anyway. I started with Leo. Always fancied finding the triple - but no luck. So I had a shot at M13 in Hercules. I have seen this in bins plenty of times, so knew exactly where to find it. And boom! Using an 18mm EP (x67) is was a lovely blob, I could make out individual stars, even against the light background, averted viewing helped. I tried my 6mm plossl (x200) and I was surprised how nice it looked. Really 'glittering' even though it was rushing past the view so quickly. Then I tried M92, but couldn't find it. It was still hard to find much in the finderscope, let alone do any star hopping - not for my noob skillz. Next I had a look at double double. Easy enough to find, but with the 6mm, I could only split one of the pairs. Not sure if it was the viewing, my eyes, the plossl, or just lack of experience. It's not my best eyepiece, though. Anyway - nearby was M57 the Ring Nebula, so I thought I'd have a shot, not really knowing what to expect. Wow! It's a nebula, it looks like a ring! It was so clear, both in 18mm and 6mm eyepieces. This was the highlight of the evening for me. I really didn't think it would be so obvious in these conditions. OK - I was cooking on gas now, and at 1am the sky was as dark as it was going to get. I thought I'd try the Leo Triple again. I got more comfortable and took my time star-hopping using Sky Safari. Still no luck though, trying the 25mm and 18mm EPs. I am very confident I was looking at the correct locations, everything matching-up with Sky Safari, but nope, nothing. It was getting low on the horizon and the LP from the rail yards was obvious. So for a final shot, I thought I'd try M51, the Whirlpool galaxy. Straight up, almost; star-hopping was a little tricky but I took my time and after a few attempts I found it! Just a couple of pale 'clouds' with averted vision, but definitely the Real McCoy! Can't wait until we get some dark skies again. The Leo Triple will have to wait until next spring, I guess.
  21. 21 points
    I finally got this data set to a point that I can live with. I struggled with star shape and palette. I have many versions of this image--most very gaudy.. Its not perfect by any means--but I am no longer compelled to labor over it . I think if I had more data I would achieve a bit better definition in the dimmer regions of the frame. Maybe I am overcompensating a bit for my earlier cartoons and could use a bit more saturation. Though there is something to be said for the subtle approach. I have a version, the one just before this one with a bit more noise control ( a lot more). But the detail is finer in this one. This image has one very small iteration of gentle noise control. FSQ 106 with .6x reducer and ASI 1600 with Astrodon 3nm filters: Ha 53 300sec; OII: 74 300 sec; SII 70 300 sec
  22. 20 points
    Having a good run of clear nights lately, and I am having a ball with this excellent Samyang lens and getting images I have done before but with a wider FOV. Taken over the last couple of nights (whilst chatting on Anybody Playing Tonight thread). Ha 21 x 600 Oiii 4 x 450secs binned + 7 x 300secs binned Sii 10 x 300 secs binned + 4 x 450secs binned RGB 5 x 150 each (for stars) Samyang 135mm F2 Stopped down to F2.8 Atik460EX and Baader filters on HEQ5 Little Rosette at bottom of image Total Imaging time 6 hours 32.5 minutes
  23. 20 points
    Despite yesterday's cloud, I managed to see comet C/2020 F8 (SWAN) though binoculars. At first I just explored the clear skies overhead, using the trusty Helios LightQuest 16x80 bins to pick out several Messier objects, and track the ISS as it passed overhead. I had some nice views of globular clusters M3, M5, and M13, and galaxies M51, M65, M66, M81, M82, and M101. The latter was surprisingly easy, indicating pretty clear conditions overhead. Not so to the north. I patiently waited for the cloud bank to the north to budge, and by 0:30 I could make out Algol (beta Persei) and two fainter stars above it, but a dark tendrils of cloud in between kept blocking the view of the location of the comet. Finally, around 1:00 I repeatedly spotted a little fuzzy ball, exactly where the comet should be. That's my 28th comet bagged.
  24. 20 points
    An early Ring Nebula imaged with an Esprit150/ASI1600mm on a Mesu, it was just rising over the trees as astro-darkness fell. 3 hrs each RGB and 3 hrs Ha taken over the last week. Processed in APP, Pixinsight and Photoshop.. I don't yet have enough Ha to show the outer ring in any detail and adding it to the Red channel proved unnecessary. I did use it though after sharpening in Pi using deconvolution and merging it with a deconvolved RGB pseudo luminance to sharpen the RGB. Also visible faintly above left of M57 is barred spiral galaxy IC1296. M57 is approximately 1.5 x1 .0 arc minutes, the image is presented at the native pixel scale of 0.73"/pp Thanks for looking Dave
  25. 20 points
    NGC 2903 is a barred spiral galaxy found just below the head of Leo at around 20 to 30 million light years from Earth. It has a significantly high rate of star formation all around the core of the galaxy, visible as the pinkish HII regions. Apart from that, it's a pretty regular galaxy. It's a bit smaller than the Milky Way at around 80,000 light years diameter. It makes for a pretty picture though! It is a 9th magnitude fuzzy blob, which is visible in a telescope. Though it wasn't catalogued by Messier, perhaps he just knew it wasn't a comet?! It was first discovered and catalogued by William Herschel in November 1784. The faint fuzzy blob below NGC 2903 is the distant irregular galaxy, UGC 5086, some 24 million light years from Earth. Technical Specs Celestron EdgeHD 8" with QSI 683-WSG8 and Astrodon 31mm filters, all on a Mesu-200 mount. L = 39 x 1200s RGB = 18 x 600s TOTAL = 22 hours I also shot some H alpha data, but it didn't add anything to the image, so I didn't use it. It is amazing how much the HII regions have shown up with just the Red filter. The data were gathered at the end of March, but I've only just got round to processing it. All done with APP and PhotoShop. I hope you like the image and I look forward to hearing your comments. Clear skies!
  26. 20 points
    Quite an interesting galaxy, with the dark dust band over the central portion. I was struggling a bit with the colour, then I realised I had only 50-60 minutes per channel, so I accept the compromises. The stars were elongated - balance/tilt issue - but thankfully I think I have sorted this. RED = 50 minutes GREEN = 60 minutes BLUE = 50 minutes LUM = 2 hours 45 minutes TOTAL = 5 hours 25 minutes Thanks for looking Adam.
  27. 20 points
    Hi all at last had my big WOW moment got Saturn and Jupiter for the first time this morning it was amazing , I am still amazed how newtonian telescope work
  28. 20 points
    My first attempt at M109, a galaxy located in Ursa Major which is about 55 million light years distant. In the image below you can also see quite a few other background galaxies - the ones marked PGC37553, PGC37700 and PGC37621 have recession velocities very similar to M109 and are classified as dwarf companion galaxies. The LRGB image below represents 16.5 hours integration and was taken with my Esprit 150. Alan M109 M109 (annotated) LIGHTS: L:37, R:21, G:23, B:18 x 600s. DARKS: 30, BIAS:100, FLATS: 40 all at -20C.
  29. 19 points
    Whilst waiting for delivery of a Skywatcher ED80 , I'm trying out some camera lenses, partly to start learning about guiding and also to give me a few images to practice processing. Here's my first attempt at a galaxy - M101. 1hr 40mins total exposure time, made up of 15x 400s exposures (plus darks, flats and bias). Taken with a Sigma 150-600mm zoom lens and EOS80D mounted on an HEQ5. I know it's not brilliant and it really requires more exposure time, but I'm just pleased to be able to see some spiral structure.
  30. 19 points
    This spectacular globular cluster contains several hundred thousand yellow and blue stars. It is about 25,000 light years away. This was taken last Sunday. I very nearly didn't set up as the forecast was for high cloud. I'm glad I did though, as I had some of the best seeing conditions of the year so far. Guiding was just about flat. The image has very nearly processed itself! Apart from stretching, removing the green background and balancing the colour in Siril, I have done very little to it. I am amazed how sharp the stars are. 18 x 300s, with darks, flats and dark flats. Total exposure time 1 hour 30 minutes. Processed with DeepSkyStacker, Siril and Photoshop (re-sizing and adding text only). Taken at f6.3 with the C11, ASI294MC Pro and Optolong L-Pro filter.
  31. 18 points
    I think they do. It seems to be enjoying it Regards
  32. 18 points
    I've been less active lately in this hobby, but I've a few images done, others waiting in the pipeline to be processed. This is a "crowded" area of our Milky Way galaxy, visible all summer from the northern hemisphere. The Cygnus constellation is home of many named and nameless nebulae. Starting from the left (North), below the brightest star, Deneb, the Pelican and the North America Nebulae are very popular; going to right, just below the brightest star close to the center of the image, Sadr, lies the Gamma Cygni Nebula. A bit towards the top-right there's the Crescent Nebula and going forward top-right, there's the Tulip Nebula. Finally, at the bottom-right corner, the Veil Nebula, a super nova remnant. All these are surrounded by shiny gaseous filaments or dusty patches blocking the light. I started this during the pandemic lockdown. All of the data was captured from my hometown from a balcony brightly lit by a sodium street lamp, but the narrowband filters did their job well, blocking successfully the sodium emission. A total of 23 hours is made of 2x3 panels composed in a larger mosaic, each panel consisting in about 1h of exposure for the red Hydrogen and 3h of exposure for the cyan Oxigen, all through a Sigma 105 macro stopped at F/4, ASI1600MMC with 6nm Astronomik filters. I'm planning to shoot RGB data too and make an RGB/HOO composition. Cheers and clear skies! astrobin link: https://www.astrobin.com/r22yre/ flickr link: https://www.flickr.com/photos/170274755@N05/49939128338/
  33. 18 points
    IC1396 bi-colour image HOO > RGB. North at top. Ha and OIII Astrodon 3nm filters, Asahi SMC Takumar 200mm f4 lenses and ASI1600MM-Cool cameras. 5m x 51 = 4h 15m total integration of Ha subs and 20m x 9 = 3h total integration of OIII subs. Cameras at unity gain (139). Processed in PixInsight and GIMP.
  34. 18 points
    Loads of clouds around this evening but I got lucky and had some nice views of Venus and Mercury in the same field of view with my Takahashi FC100 refractor. The Panoptic 24mm gave me a 1.8 degree true field which framed the 2 planets perfectly. Venus thin crescent on one side of the field and Mercury's tiny gibbous disk on the other. I think they are around 1.25 degrees apart just now. Despite Mercury's very small apparent size I could tell that the illuminated portions of both planets were facing the same way - towards the Sun of course ! No time for images because I was catching glimpses between clouds but it was a lovely sight for those few minutes when they both came into view. 2 worlds, one of them the same size as Earth and 46 million km away and the other 38% as large as our home planet and 161 million km distant. Both basking in light from the star that we share with them. This is why I do this hobby
  35. 18 points
    Last year i bought a used Qhy163c. Then baby no.2 came along and it just sat in it's box (the camera, not the baby! lol). I wasn't impressed with the camera tbh (i found it noisier than i was expecting) so i recently just sold it. Thankfully I did at least manage to get 1 actual image out of it first, and this is it. Shot over 2 short nights, due to the rapidly fading Astro Dark (which is now gone until early Aug) here in N.I. I went for M106 as it was nice and high in the sky. I don't think i have ever shot something as high as this, it passed very close to Zenith, and the subs showed it. The lowest HFR SGPro reported was 1.82, which is way lower than i've ever seen before. In total i managed 269 subs of 90secs, so about 6.7 hrs in total, using a SW 80ED and an IDAS-D1. Stacked in APP and processed in PS. Noise was a thorny issue, and caused me a fair bit of consternation as to how much NR to apply, and how much noise to leave in. Interested to hear what you guys think, all feedback welcomed as always. Clear skies and stay safe.
  36. 17 points
    Beautiful solar viewing today, just a tad breezy. Here's a time lapse from this afternoon, it covers approx one hour in the life of today's biggest prom.
  37. 17 points
    Reverse-Engineering the Skymax 180 What follows should be of interest to anyone who wants to know any of the following 3 things about this scope. 1. What it looks like inside, its design, how it works, and how to dismantle it and re-assemble it safely (yes I’ve seen that video of someone disastrously taking apart a Skymax 150!). 2. Its real dimensions, including all the major components of the scope including internal mirror separation/s; 3. Its “key numbers” such as effective focal length for various amounts of back-focus or mirror separation, to allow more confident estimation of magnification, fields of view, exit pupil sizes for various configurations. When I went to try to find these details, I couldn’t find anything reliable online. It started by me noticing that the Moon, always very close to 30 arcminutes across, was filling more of the field of view than the official spec of the scope suggested it should. The scope’s advertised focal length is 2700mm, but it seemed that in the set-up I was using it was behaving more like a 3000mm. That set-up was an external Baader Diamond Steeltrak, adding quite a lot to the back-focus compared to the supplied visual back. I did a little searching around, and quickly came across the formula for the effective focal length of a catadioptric: namely EFL = f1.f2/(f1-f2-s) where “s” is the separation between the mirrors. Seeing as the focus-mechanism relies specifically on changing this separation, I had all the excuse I needed to do something I’ve come to enjoy doing: survey the scope and/or take it apart to see how it works. At the same time I also did a focuser-axis-vs-primary-optical-axis test, and discovered that the two axes differed by around 8 arc-minutes; enough to investigate trying to fix it. As it turned out, this was not a problem, it was a design feature (more later)! Anyway, to investigate, I was going to have to see how the primary mirror was affixed to the central tubes and how if at all it might be adjusted, and to do that I was definitely going to have to take the scope apart. Unfortunately as stated I couldn’t find anything online either about how properly to take it apart, in particular the mirror, focusing and collimating end; and neither could I find anything I trusted about its various dimensions. I did find one article whose author calculated back-focus and EFL relationships for a Skymax 180 of almost identical age to mine, and who even went as far as to run its dimensions such as he had them (including corrector-plate refractive index!) through a ray-tracing program; but many of the dimension inputs he used I think must have been assumed or guessed: when I measured and re-measured them I found them very different from his. And the formulae are extremely sensitive to those dimensions being accurate. Disassembly, Adjustments and How It Works The rear assembly comes apart into 2-3 main pieces: the main rear cell, i.e. the cast-metal “back end lump” of the scope you can see from the outside, out of the back of which is poking the focus knob and the visual back; and the inner mechanism comprising the 2 nested baffle tubes, the primary mirror, the focus-mechanism and the collimation-plate. The primary mirror, outer baffle tube and the focus-rod receiving plate are all effectively one bonded-together piece. Although the mirror sits against a flange in the outer baffle tube, it’s heavily bonded on so trying to address any baffle-tube orientation problems is nigh impossible. The inner baffle tube, which sits inside the outer one, becomes at its bottom a stamped flat-metal plate with three threaded holes and a cut-out recess to allow the focusing-rod through. The three holes correspond to the main collimation bolts at the back of the scope, and they are the only things supporting the primary mirror assembly inside the OTA. In other words, those 3 collimation bolts hold the entire mirror and baffle-tube assembly inside the OTA space, and adjusting them points it around inside the OTA. What this means is that the visual back on the OTA IS NOT DIRECTLY CONNECTED TO THE BAFFLE TUBE. There is a gap, and potentially an axis-kink. See my drawing, comparing the Skymax to my Intes M603: What it also means is that blindly removing those 3 collimation bolts as a first step will cause the mirror assembly and baffle tubes to, at best, hang off the focus-rod inside, and at worst, if you’ve already removed the focus receiving bearing from the rear cell, the whole baffle and mirror will be set free to collapse onto the corrector plate and secondary! Therefore: if you really wish to dis-assemble, follow my instructions below! This arrangement is interesting. In my Intes, the visual back is part of the baffle tube which extends all the way through the rear cell: eyepieces, diagonals and cameras attach directly to the baffle tube. In the Skymax here, the visual back is part of the rear housing of the OTA, only attached to the baffle tube in a subsidiary fashion via the collimation bolts, and the whole “viewing tunnel” is effectively kinked at the rear of the scope. So collimation on the Skymax is mostly getting the baffle tube to line up with the visual back and eyepiece axis. That certainly helped explain why my eyepiece axis and mirror axes were “out” when I measured them. But if there’s misalignment of the corrector plate, or if the secondary mirror-spot is out of place, then I guess there’s little you can do about it. The native focus mechanism is very simple, far simpler than that of the Intes. It comprises a threaded rod held at one end by a bearing in the main scope back cell, and at the other end attached to a rigid metal plate bonded behind the primary mirror. Turning the knob causes the plate (and hence the mirror and outer baffle tube) to move up and down the tube at a rate of about 0.8mm per knob-turn. Obviously, there must be a tiny amount of clearance between the two tubes, and it’s this clearance that causes the dreaded “mirror slop” when the focus knob is engaged. Next came the front cell which contains the 18-19mm thick corrector lens, and appears to have coatings (green and pink reflections each evident). On the inside surface of the corrector lens is the secondary mirror, an aluminized spot surrounded by a cup-shaped black plastic baffle skirt. This skirt is glued to the secondary mirror, but in my case NOT CENTRALLY! I removed it, thinking in the process that I was reducing the Central Obstruction as well, but soon realised that because the primary mirror hole and retaining-ring were themselves much wider than the widest part of the secondary baffle-skirt, there was no point. Nonetheless having removed it, I cleaned off the residue, re-centred and re-attached it. With the baffle-skirt in place, the remaining exposed secondary mirror is 36.5mm diameter. The main tube itself was a loose fit: larger than the fitting-flange on the front cell, and smaller than the flange on the rear cell in each case by more than I was entirely happy with (it fits inside the lip of the rear cell and outside at the front cell). As such, the tube had to deform in each case slightly when doing up the 4 retaining screws at each end. I plan at some stage to get a carbon tube with a better fit. The dovetail is bolted to the tube, not to the much-more-solid cells, and the tube is only held on to the chunky front and rear cells by those 4 screws each end. Rings for this scope would be a good addition, or a longer dovetail to attach directly to the main cells. Step by Step Dismantling 1. Attach a visual back that extends beyond the focus knob. You’ll be using it to place/balance the rear assembly vertically on a flat surface later. 2. Remove rubber focus knob (it simply pulls straight off). 3. Rotate the protruding brass cylinder clockwise, to gradually expose the threaded rod. 4. Unscrew and set aside the small central Philips screw (and possibly small washer) at the top of the threaded rod (it may be a C-clip instead, in which case remove that). 5. Remove main telescope front plastic “lens cap”. 6. Place scope “front down” on a level surface. 7. Partially, maybe ½ a turn, unscrew the three main (bigger) collimation bolts at the back. BUT ONLY UNTIL THEY LOSE THEIR TIGHTNESS – DO NOT COMPLETELY UNSCREW THEM YET! THE MIRROR IS ESSENTIALLY HANGING OFF THESE SCREWS INSIDE THE OTA! Do not touch the smaller recessed “locking screws” – keeping them in place allows you to restore the position of the primary at roughly the same orientation when it comes to re-assembly. 8. Unscrew the 3 screws on the flange around the focus-knob, and set them and the flange-plate aside. 9. Unscrew, by hand, and set aside the exposed brass focusing assembly (ACW) all the way off (perhaps 20+ turns!). Also notice and remove a black rubber washer underneath the assembly. Be careful of the evil black grease! 10. The threaded rod, covered in black grease, will now be poking up through the hole in the back plate. 11. Unscrew and set aside the 4 screws on the side of the OTA holding the rear cell to the main OTA around its outside. From here you need to be very careful with your movements to avoid things getting knocked and toppling over. 12. Lift the whole rear assembly out of the main tube and carefully place it on the level surface “focuser down” (i.e. collimation screws and visual back at the bottom). 13. With a small/short hex socket-insert, with your fingers from underneath, carefully unscrew/twiddle off all the way the 3 main collimation bolts that you loosened earlier. Once done, the primary mirror assembly and baffle tubes are now only resting on the OTA’s rear cell. 14. Whilst supporting the rear cell on your flat surface, and holding the baffle tube, gently lift the baffle tube (and primary mirror and focus-rod) away from the main rear cell. Be careful not to lose 3 hidden fat little washers between the plate at the bottom of the baffle-tube and the rear cell: they can stick to the underside of the plate and fall off later if you don’t pay notice them. 15. Remove the O ring around and near the top of the inner baffle tube. This O ring prevents the outer tube from sliding all the way off if somehow the focus-rod isn’t holding it. It’s tricky to remove with all the grease lubricating the two tubes: try not to damage it. 16. You can now separate the two tubes by pulling the outer tube off the inner: the outer tube with its mirror, focus-plate and (evil-black-greased) focus rod; and the inner, with its flat plate at the bottom. 17. Further dis-assembly of the primary mirror and its components is not possible, as you will see that the primary mirror is extremely heavily bonded in place on its tube. Re-Assembly 1. Place the rear section on the hard surface, resting on the Visual Back 2. Place the 3 fat doughnut black rubber washers on the 3 larger collimation-holes (they act as crude tensioning-springs for the collimation-bolts) 3. Carefully place the collimation-plate/inner baffle-tube so that its 3 holes match the main collimation holes, and such that the focus-knob cut-out matches the focus-hole in the rear cell 4. From underneath, using a short suitable hex-insert, screw in the 3 main collimation bolts most of the way, but do not tighten 5. If necessary, re-grease the lower part of the baffle tube where the outer will slide over it 6. Gently and carefully lower the primary mirror / outer baffle-tube onto the inner one 7. Re-fit the rubber O-ring into its slot 8. Remove excess grease from the upper end of the baffle tubes 9. Bring the 2 halves of the scope back together again: carefully lower the rear assembly back into the main tube, and re-attach the 4 screws. The scope should now be on its front, with the visual back “up”. 10. The black-grease threaded rod should now be poking up through the focuser-hole. Replace the black flat rubber washer into that recess 11. Screw on the focuser assembly, “thicker bit” first, clockwise onto the threaded rod until it’s all the way into the recess, and a couple of turns more. 12. Screw on the small locking screw onto the end of the threaded rod (or replace the C-clip if that’s what it is) 13. Replace the flange-plate and secure it with its 3 screws 14. Push the rubber knob back on 15. Screw the (larger) collimation-bolts back until they are reasonably firm: having not touched the smaller locking-screws, this last action returns the primary mirror assembly to close to the orientation it was before you started. Dimensions and Measurements A. 45.4 mm: Front Rim to centre of Corrector Plate B. 18.6 mm: Thickness of Corrector at Centre C. 42.5 mm: Depth of Secondary Baffle Skirt D. 421.5 mm: Front Rim to Front Rim of Rear Cell E. 357.5 +- Nx0.787 mm: Secondary Mirror to Centre of Primary Mirror where N = no. full turns ACW from where supplied visual back & 2” diagonal come to focus (more back-focus => smaller separation => bigger focal length) F. 83 mm: Front of Rear Cell to Flat Back of Rear Cell (not including Visual Back attachment!) G. 37 mm: Exposed Diameter of Secondary Mirror H. 58 mm: Secondary Baffle Skirt Width (at wide end) I. 42.5 mm: Depth of Secondary Skirt J. 63 mm: Diameter of Primary Mirror Retaining Ring (i.e. wider than secondary skirt!) K. 200 mm: Primary Mirror Diameter (i.e. oversized) Other quantities not shown on diagram: F1: 472 mm: Primary Mirror Focal Length (measured as half the centre of curvature, itself measured from its reflecting a point source F2: 127.92 mm implied Secondary Mirror Focal length (to force formula to give 2700 mm with supplied back and diagonal and all other measured dimensions. Very difficult to measure). also: - 0.787 mm pitch of focus-knob (movement in primary for one full turn of native focus-knob) - 665.3 mm Circumference of lip of front cell (=> diameter 211.8 mm) - 670 mm Circumference of inside of OTA tube at front (=> diameter 213.2 mm) - 1.60 mm OTA tube thickness - 682 mm circumference of INSIDE lip of rear cell (=> diameter 217.1 mm) - 681 mm Circumference of outside of OTA tube at rear (=> diameter 216.8 mm) The way the main (steel) tube fits on to the front and rear cells is worth taking note, if you plan to fit a carbon tube, for instance. The tube slots OVER the cell at the front, but INSIDE the cell at the back. The difference between the two meeting-face diameters is 217.1mm less 211.8mm, i.e. 5.3mm. Which means that should you wish to upgrade to a, say, carbon tube, it would need to have at most 2.65mm wall-thickness. The steel thickness on this scope is 1.6mm, which is accommodated by the fact that it’s flexible, and on this scope at least needs to flex to fit. The native focus mechanism is, as shown, a knob on the back which moves the primary mirror up and down the tube. The secondary mirror is fixed in place as an aluminized spot on the back of the front corrector lens. Focusing via that knob changes the separation between the mirrors, changing the focus-point and back-focus and changing the system’s Effective Focal Length, according to the formula EFL = - f1.f2/(f1 – f2 – s), s being the mirror separation. If I could simply find out what the individual focal lengths of the two mirrors were, and what the mirror separation was for given positions of the focus knob for a given back-focus amounts, I could calculate what focal length a given arrangement engenders, and therefore construct a more accurate mag / exitpupil / FoV ready-reckoner to stick to the side of the scope. I started by roughly estimating what these numbers might be just by “eyeballing” the scope, doing some crude measuring and putting together a simple spreadsheet. I hoped that would be close enough and I wouldn’t have to dis-assemble. For instance f1, based on reflecting a point source back to itself from the mirror seemed about 450mm, f2 around 90mm and judging by where the main mirror looked positioned, the mirror separation looked something like 370mm. Then I noticed something about the EFL formula. f1 x f2 is going to be a reasonably large number, in this case 40,500. f1-f2-s is going to be quite a small number, here -10, suggesting an estimated EFL of 4050mm. Hmmm. Big number divided by small number is going to be very dependent on the small number, especially if that small number is a difference in measurements. It doesn’t take much leeway in those numbers for that denominator to be, say, 0mm for example and the calculated EFL to become infinite. Or even negative! Clearly, more precise dimensions rule here. “Rough estimates” weren’t going to cut it: I could come up with whatever results I wanted just by slightly varying the key dimensions. I was going to have to make accurate measurements. Two of these accurate measurements initially presented a challenge: the precise thickness of the corrector lens (the mirrored spot is inside the tube and at the centre of a highly curved and rather thick glass plate); and the precise position of the centre of the primary mirror (it’s recessed into the rear cell of the scope, has a big hole where its centre should be and you can’t see the thread which moves it). I needed to be ingenious about each of these. My digital micrometer saved the day. The back end of it can be used as a depth gauge, and using it I was able to accurately estimate the thickness of the corrector plate and, because the primary mirror is recessed into the rear cell, the distance below the rim of the edge of the primary (I also needed to take account of the sagitta of the primary). The distance between the front and rear cells was trivially measured from outside the fully-assembled tube. And finally, using the pitch of the threaded focusing-rod, I was able to determine the mirror separations for any position of the focus-knob. Effective Focal Length and Back-Focus All the above having been done, I was now in a position to estimate EFL for various back-focus settings, and for my various actual set-ups. These estimates are predicated on the assumption that with the supplied diagonal and Visual Back, the focal length is actually as indicated on the scope’s plaque, i.e. 2700mm. The only quantity I couldn’t easily measure, the focal length of the secondary, was the “degree of freedom” I could change that allowed me to “fix” the EFL to 2700 for a certain set-up. At some stage I’ll try to actually measure it, but this will do for now. Below is a chart showing Effective Focal Length of the Skymax180 against the likely range of back-focus behind the OTA: The geometry means that actually the EFL is a linear function of back-focus, which surprised me (see formula below). Incidentally the 440.5 is the distance from the secondary to the back of the OTA. For the Skymax 150, for example, the formulae would be the same but with a different value of “440.5” (I’ll update this post with Skymax 150 values and dimensions when I get back to London). A couple of extra data points that I didn’t include on the chart are those for the “end-stops” of the native focuser travel, i.e. 0 turns ACW and 29 turns ACW: 0 turns => -40mm backfocus (i.e. inside the rear cell!) => 1952mm EFL => 375mm mirror separation 29 turns => 1113mm backfocus => 6200mm EFL => 354mm mirror separation For those who prefer formulae to calculate these things: Effective Focal Length EFL = (BF+440.5).F1/F2 + F1 all quantities in mm; BF measured from rear of OTA Mirror separation s = F1 – F2 + F1.F2/EFL In the use of these formulae for estimating the various quantities, I’ve ignored the effect of the corrector plate. The only exception was the measurement of the Primary’s focal length, which I measured with the corrector plate removed. I don’t think it matters too much, and hopefully is partially compensated-for by my back-solving of the focal length of the Secondary to achieve 2700mm in OEM configuration. (Re-)Collimation I now had knowledge of what was mechanically going on behind the mirror and what the collimation bolts did! As mentioned, those 3 bolts are the only things attaching the primary mirror support assembly to the rest of the scope, and they basically point the mirror around the inside of the tube. The secondary is fixed, the visual back attachment is fixed, the only thing that you can change is the orientation of the primary inside the tube. Thus collimation involves aligning the primary’s axis as well as possible with the visual back’s axis and the centre of the secondary. If either of these are out of place, it’s an exercise in compromise. A popularly suggested method for aligning Maks and SCTs etc is the “hall-of-mirrors” method. But I’ve found it unsatisfactory: it can tell you if you’re reasonably close, but if you aren’t it doesn’t tell you what to adjust to get it right. I’ve found that star-test collimation is much more intuitive and sensitive. Point at something like a 2nd-mag star, ideally Polaris because it stays still, on a night of not too bad seeing. Using at least a 10mm eyepiece, and very slightly defocusing, you'll notice a set of concentric(ish) rings around a small hole with a point in the middle. Very likely though, the doughnut you see will be "squashed" towards one edge. Establish which collimation bolt best corresponds to that squashed position, by putting your hand over one side in front of the scope and seeing where the gap appears in the view: the bolt closest to that gap, or the one opposite, is the one to move first. Adjust that collimation bolt, and the squashiness will either improve or dis-improve. One proviso: as you turn the collimation, the star will move out of view, so have your controller handy so you can keep it in view during the process, to avoid spending 10 minutes re-discovering Polaris at high magnification (been there, done that). Keep going through that process until the ring-pattern is as symmetric as you can make it. I find that it comes right quite suddenly at the end. You could go one step further to do super-fine collimation (I often don't bother) by going to super-higher magnification, getting to best focus, and "symmetricizing" the Airy disc, but to do that you need almost perfect seeing which is rare. Whereas symmetricizing the doughnut can be done on more ordinary nights and gets you very close. Once there, it should hold reasonably well for the future. People call catadioptric collimation a "dark art", and one of the reasons I think is that the various internal designs are often very different, and collimation is doing different things "inside". And they never tell you what's inside, so you are effectively adjusting something by blind trial and error hoping that whatever it is lines up. If you’ve got this far, well done! And thanks. I hope this will prove useful to anybody else with a reason to want to know how this scope and its siblings (Skymax 150, 127 etc) actually work inside. Cheers, Magnus
  38. 17 points
    Still and clear. Main target - a couple of doubles in Ophiuchus (low, south). Bresser Dob. Having recently operated at nightfall, it was good to see so many stars on show at this time! Targeted Cebalrai - in the same FOV I saw the Summer Beehive Cluster IC 4665 - large, loose, and bright. Then easy hops (in roughly 2deg stages) to 70 Oph (binary, close match, 5.9" separation). Going from x35 to x64, got the split. The clearly orange secondary lay at about 2 o'clock. I then aimed at 71 Oph with its bright, close field star, both "above" 72 Oph, also with a bright field star. A hop down led to Sigma 2276 - a triple system, visual double, matched, 7.0". A beautiful matching pair of eyes, very close at x35 - nice and clear, not too bright, with fainter stars all around. Even nicer at x64. After 3am, the sky was getting lighter, esp. low south where more Ophiuchus doubles awaited, but getting started there would have been trickier. After a successful aim, I had a quick look at M13 (some detail x127), then noticed Jupiter, low, east of south, and Saturn further east. (Mars was further east again, behind a house). All too low for the Dob, so I put the AR 102S frac on the job. What a delight to see Jupiter again - two belts - Ganymede and Io close on one side, Europa close on the other, and Callisto further west. Good at x75, less sharp at x150. Blackbirds started up at 3.40 - lovely. Over to Saturn - again, great to see it after a long break, and with the rings well tilted towards Earth. A faint Titan was easily seen to the west, x60, x100. Finished after two hours - little else on show but the gas giants by then. Nice haul - 2 doubles, 2 planets, 2 clusters (open, globular), and 5 moons. Doug.
  39. 17 points
    I wanted to collect Ha for this one but time ran out--the galaxy hit the treeline leaving only about an hour of imaging. Maybe next year. I was only able to capture 22 green subs. It will be rainy for a week, then the Moon will come and I am afraid that's it for M100 for me. I think I eked by with the green I have. 22 subs is almost 2 hours. I was shooting for 4 for each of RGB. Seeing was unusually good during this shoot. TOA 130 with ASI 1600 and Astrodon series DE true balance filters Red: 42 300 sec sec Green: 22 300 sec Blue 49 300 sec Lum: 96 300 sec This is the first attempt--binned in software 2x2
  40. 17 points
    hi everyone. nothing special just a few things from tonight with my ace wife scope was set up and cooling by 5, then colimated later on. aligned the nexus on arcturus and polaris using skysafari6 pro(loads better than 5) set out on all the usual targets but seeing/contrast was poor. then after midnight wow, the sky came alive m51 has lovely joining spiral arms lots of definition put the 8e in and the sky took it no problem m101 not quite as good but spiral arms everywere m81/82 not the best but taking 300x no problem makarains chain was brilliant heather had 6 galaxys in the fov using the apm 20 well cool. whale galaxy ,fireworks showing good detail as was m22 havnt seen that for a while. then on to the old favourites m13 , m57 lovely colours m27 then the veil and cresent absolutely amazing, cresent was almost the best i have seen it. god its great to be out, wish i would of gone to my dark site now cheers everyone
  41. 17 points
    Hi All, just finished a process of my M101 data taken a few days ago. All subs are 6 minutes, binned 1x1, total integration time 6hours 24 minutes. L x 13, R x 18, R x 15, B x 18.
  42. 17 points
    Hi all, First post on Stargazers Lounge, though I've been looking at this site for quite a while. I made an aborted attempt at astro-photography a couple of years ago, got a certain distance with it, but then gave up. Under lock-down, all the clear nights recently have tempted me to have another go. A couple of attempts in, and here's the first decent picture I've managed - The North American Nebula which is just starting to rise in the West. This is taken with a Sigma 150-600mm zoom lens at 190mm mounted on an HEQ5 mount, and using a Skywatcher finder scope with a QHY5LII colour camera mounted on a side-bar for guiding. The standard Sigma lens foot is far too flexible for astro work, so I've clamped up the lens barrel with another lens collar to mount it to rigidly to the dovetail bar. At just 190mm, this arrangement seems rigid enough for tracking., and I managed 20*300s exposures before giving up at 3am. Any comments/feedback or suggestions for improvement welcome.
  43. 17 points
    Here is a compiled image of Venus changing phases from January 18th to May 11th. Best or decent images were picked and gathered into a composite! All photos are in their apparent size. As Venus travels around the Sun and viewing this from Earth it makes phases like our Moon. Gear used: Celestron Nexstar 127 SLT ZWO ASI120MC-S GSO 3X Barlow Sharpcap Photoshop Update: Another Venus capture added that due on May 11th
  44. 17 points
    The power of dark skies and fast optics I am going through some files on my hard drive. Two years ago I made a trip to La Palma with a rented Canon 300mm f/2.8 lens, a star tracker (Astrotrac) a dslr and a intervalometer. This is one of the images as a result. The lens was used wide open. The camera was a Canon 5ds. 50 megapixels per shot (which is nice and the Astrotrac could handle that unguided for up to two minutes), but a lot of banding noise and not very sensitive to red. 40 times 90 seconds exposure at iso 1600. For the record: This lens (wide open) has "dark lighthouse beam" artefacts on stars. I have corrected it for Rigel as I found it distracting. All the other stars still have this artefact (e.g. lop left). I certainly will return to La Palma when the situation normalises.
  45. 17 points
    Whilst observing the sun in Ha today, it dawned on me just how ludicrous I must look, tucked away in my observing hood. For the benefit of the forum, and to cheer you up, this is how I looked! The lengths we go to to get the best views. I must say it does make a real different to the contrast and visibility of fine detail in the proms so is well worth the funny comments from Mrs Stu. All other similar contributions welcomed to share my pain
  46. 17 points
    The daytime weather was curious here in Cheshire yesterday, with a rapid drop in temperature. It was cloudy all evening, but when I went outside to protect the hanging baskets about 11 pm I noticed it was clearing. I went back inside after a few chores to find that the house lights were very dim. I then heard a few burglar alarms up the road going on. Looking up and down the road I realised that the whole village had a power cut, with all the streetlights off and most houses. Surprisingly my house had at least some power, although I immediately switched off all the lights. Back outside, I quickly set up the Tak TSA 120 and started observing. The sky was very transparent and of course the background light level was very low. I spent the next couple of hours galaxy hopping in Leo Coma and Virgo, as well as the usual suspects like M51 and M81/2. What a night! Power was re-established at 1.30 am. Thank you Scottish Power!
  47. 17 points
    This 2 pane mosaic was the first outing of my FrankenOptics scope on a iEQ30 mount and also my first mosaic. There maybe some interesting learnings for others, so I will describe my experiences in making this image a little bit: -The refractor is a collection of pieces screwed together with tape in two places. The objective cell is a William Optics 80mm f/6.9 FD ApoGrade. This is an upgrade that was sold many years ago by William Optics to convert a semi-APO Megrez 80SD into an APO refractor (Megrez 80FD). The tube is not original, the focuser had variable slack, and the original focal reducer/flattener was OK at the time for tiny sensors, but not for my current APS-C camera (QHY168C). So, I bought a "cheap" focuser (GSO linear) and a not so cheap WO 6AIII reducer/flattener. Long story short, I was not able to completely eliminate tilt and curvature, but enough to my liking (and patience). I taped both the focuser and the variable ring reducer, so I would not inadvertently mess up with the alignment during transportation. There is color fringing in this scope, but it is not that bad (it still is a doublet). So much for the eccentric bit. -The iOptron iEQ30 that I had bought second hand last year turned out to have a periodic error of 60 arc seconds (peak to peak) and at some points a bit steep. I had 4 clear nights in a row for making this image. The first night I could not guide better than 2.5 arcsecond RMS in PHD2 (elongated stars). My image scale is 2.2 arcseconds, so this is not good enough. I improved on this every night until I got to 1.2 arcsecond RMS the last night. Not stellar, but just enough for this image scale. The trick that did it for me was using the Predictive PEC guiding in PHD2, combined with short (1sec) guide exposures. There was also quite a bit of DEC backlash, but that was manageble. I have found some tuning tips for it's big brother, the iEQ45, so I might give that a try in the summer months. - I used a ZWO290 camera as my guide scope and once I changed the driver from ZWO native to ASCOM in PHD2, typical snr skyrocketed from 15-20 to almost 200. The image shapes changed from spikes above a noise floor to nicely formed bell shapes with a nice peak. Strange but true. - I planned the panes in telescopius.com and that worked very good! - Both panes were pre-processed separately in AstroPixelProcessor. Generating the mosaic was a non-event. I followed the guide of the tooltips and it worked on the first try. - Because my wrestling with guiding, the stars are not really round, but because it is a mosaic, it does not show that much. - Post-processed in PixInsight with a final touch in Photoshop CS6 There is a larger version here: https://www.astrobin.com/mgo1hr/ with acquisition details and a mouse over shows a great many galaxies in this image. CS, Anne
  48. 16 points
    Desperate to image something whilst waiting for Cygnus etc to get above the murk I have been concentrating on this little trio of galaxies that I hadn't heard of before searching the area for something to image. I managed to get 14 x 15m subs in Lum over a couple of nights and last night 6x5 mins of RG and B. Apart from the grunt work of calibration which was done in PI the finishing up was done in my new best image processing s/w Affinity in which I have achieved better noise reduction than I ever did in PI! Admittedly this is more data than I normally average on one object.
  49. 16 points
    I hadn’t planned to observe tonight because of the cold wind, but it dropped during the evening and I couldn’t let the clear sky go completely to waste. I also couldn’t face putting a large scope out or having too much kit to put away, so yet again these two have given me some observing when otherwise I would have had none. These two being the Zeiss Telementor II (63mm f13.3 achro frac) and the TAL Alkor (65mm F7.7 newt). After comparing them on doubles the other night (where I would put the TAL as a winner on points), I thought I would try some DSOs tonight, just to see what is possible with a tiny aperture and skies that are about mag 5 NELM tonight, fairly decent transparency too. Having checked out the Double Double, I went for M57 first. Finding it was fairly straightforward using the Rigel on the TAL then the RACI () on the Telementor. Starting at medium power (x88 in the TAL and x67 in the Telementor) there was an immediate difference in contrast, with the refractor on top. Upping to x133 in both scopes and whilst the Ring Nebula stayed very much an indistinct round blob in the Newt, the contrast in the refractor showed it as a clear ring with averted vision. Round one to the frac! M13 next, and I must say a similar story. Straight in at high power, I was surprised how large and detailed the image was. Clearly not resolved, but in the Telementor it was definitely showing speckling and some sparkling of stars with averted vision. The TAL remained steadfastly a round ball, brightening towards the centre but with little definition to it. Round two to the frac again. Could the little newt pull itself off the ropes or would it be a third round knock out? So, could I spot a galaxy under these conditions with such small scopes? As good a chance as any I would have, given the position of M81 and M82 currently. Unusually for here, the little triangle of stars that forms the star hop for me (between h Ursa Majoris and the little line of stars starting at d UM) was just about visible with the naked eye. This made finding them fairly trivial and I quickly had M81 in the x67 view of the refractor looking surprisingly good. A fairly large oval, brightening in the centre. Finding M82 was a bit more of a challenge but I soon picked that up too, a thin line of light with some vague hints of definition/mottling in the centre. Moving to the TAL, it was clear that it was to be a knock out. M81 was much less distinct and M82 was virtually invisible. I picked up vague hints, but at any power the frac was a clear winner. I popped back inside to get my 24mm Panoptic and was delighted to have both galaxies framed beautifully in the field of view at x35 and just under 2 degrees. It was a remarkably competent and pleasing view of these two galaxies given the tiny aperture and far from ideal DSO LP levels. My night vision was not particularly well developed either, so under a dark sky and better dark adapted it would do even better. Just as I was surprised that the TAL won out on doubles, I was equally surprised a how much difference there was in the Telementor’s favour on DSOs. A quick but fun session, showing the benefits of refractor contrast in this battle of the titans, the Peashooter overcoming a challenging 2mm aperture deficit to deliver the win!
  50. 16 points
    As yet another glorious day drew to a close, I set my Tak DZ on its mount in the obsy to cool ready for a night of double star exploring. As the Sun dropped behind the high tree line to my west I rolled back the roof and scanned the sky for Venus. The sky was still very bright, as although the Sun had set from my location, it was still well above the actual horizon. Within only a few seconds I'd found the planet and rapidly aimed the scope at it. The view was excellent with surprisingly steady seeing. I first looked at Venus using a 35mm Ultima and saw the most perfect little crescent holding onto a darkened globe, while set against a blue sky. It was a bit of a wow moment! Even the little 6X30 Tak finder showed the perfect crescent of Venus as its now quite a large object. DZ getting all excited like a dog waiting to go walkies. Premature sunset. Venus in the DZ showed a silver white, ice cold image, and was razor sharp. The dusky cloud tops were in stark contrast to the brilliant silver limb and especially the piercingly sharp cusps/horns. The planet's illuminated side at higher power appeared grey compared to the limb, but the greyness was not uniform. Leading away from the terminator were gentle whisps of deeper grey shadings divided in places with lighter areas. The darkest regions were where the terminator meets the bright polar regions. Using the Wrattan 15 yellow filter which is supposedly ideal for viewing Venus, I remained unimpressed, as it did little if anything to improve the contrast. However, the Wrattan 80A light blue filter was something else. With the 80A which helps highlight brighter areas, the darker cloud tops stood out well. Usually I have little difficulty in seeing the cloud detail on Venus without using any filters, but the 80A did enhance the view on this occasion. Clouds temporarily stopped play. Later in the evening however the sky was as clear as a bell. I spent some time finding a few double stars, then ended the evening checking out a couple of summer delights, M13 and M57. M13 was a bit lacklustre as there was a low gibbous moon now flooding the sky with its light, but when I increased the power using my 3.4mm HR giving 235X, the globular burst into an explosion of countless stars set against a nebulous backdrop. Glorious - and its going to get better! M57 revealed its 13.2 mag companion star just outside the nebulous smoke ring. Then the double double and Albireo before my darling wife came to tell me it was getting late and I'd played out long enough. Now I'm no double star expert but only a tinkerer. The sketches below show the eyepiece view but without the colour, as I've no idea how to do colour in negative. Perhaps I should have made colour sketches on a white background! The view is also prism reversed just to make things more awkward, but the basic idea of what the doubles were like is still there. I suppose the eyepiece view is always going to have a power about it that no drawing could ever replicate. Something for me to work on!
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