alexbb

Thank you, Martin!

Thank you, Margin and Craig! I sold the 200/1200 newton. At F/6 I never had issues with it, but it was too large for me to handle lately. I want to travel more so I downsized my gear. The bulkiest setup I use now is a dual 102 F/7 refractor setup on a GEM45. Also the EQ6-R went away, but I don't regret it compared to the GEM45 which is much lighter and more precise.

Thank you both very much!

Thank you very much!

This is another finished target for this season. I (quite) recently bought a TS Photoline 102 ED with FPL53 which performs surprisingly well for a doublet. So I put it to tests and imaging, in parallel with an older FPL51 AstroProfessional 102 ED doublet. The blue color correction is much better in the newer TS. I shoot luminance often with both and then take the highlights from the better scope. For this image I also used some older data that I had available, shot with a 130PDS, but that maybe only made my life more difficult. Not that otherwise I shot data through the refractors in a single panel with reducers/correctors, but also in 2 panels with no reducing correctors. Same about the RGB. Some shorter exposures from the backyard, some from a dark site, most of the G data from a dark site, B and R from home (clouds came in at the dark site) and a lot of other adventures. But in the end I managed to put them all together and made an image out of them. You can watch it in full resolution and see other details on astrobin: Great Orion Nebula Clear skies! Alex

I've been mostly collecting data only lately, all waiting to be processed. I wanted to acquire more OIII on this from a dark site, but with the current COVID restrictions (it is forbidden to be out after 23) I abandoned the idea and instead I'm shooting something else. So I'm calling the latest rendition the final one. Fortunately, light collecting happens faster with a dual scope setup. You can find gear details and watch at higher resolution @astrobin.

I couldn't try the other evening, but I managed this evening. I didn't follow any PixInsight tutorial as the math is simple, so I did it this way: integrated all the darks into a master-dark integrated all the flat darks into a flat-master-dark integrated all the flats into a master-flat calibrated the master-flat with the flat-master-dark and saved as master-flat-calibrated calibrated all the lights with the master-dark and master-flat-calibrated registered all the calibrated lights integrated all the registered calibrated lights You can vary 3. and 4. with calibrating all the flats with the master dark then integrate the calibrated flats. It is important not to try to normalize any of the calibration files when you integrate them. For instance, if you normalize (add an offset and/or multiply) a calibration file, the dark subtraction is no longer reliable. You can play with different combination, weighting and rejection algorithms. And normalization for the already calibrated files. Perhaps also important, disable any optimization when calibrating the flats or lights with their counter darks. And this is the result which is looking good:

Your welcome! I'll try this evening to calibrate the files in PixInsight and see what's not working properly.

Very nice! I'm happy to hear that you managed to overcome the calibration issues.

Congratulations on your choice! I was wondering... are you buying it from TS or from somewhere else? TS seem to have it again in stock quite a long time from now.

The stretched flying bat image has a strongly similar pattern as the master flat does. Are you sure you're not missing any steps in the calibration and stacking, and are the darks exactly matching their corresponding lights and flats (gain, temperature, exposure)? Also, try to avoid any optimization at the calibration phase.

It is most probably due to the AR coating on the sensor. Depending on the angle you're looking at the sensor, you'll see the pattern visually too. It seems to affect the longer wavelengths worse than the shorter ones. But don't worry about it. Calibrate the flats with matching darks for flats and you'll be fine. I had no issues whatsoever.

An idea for aligning 2 relatively light scopes: use a guiding ring at the front of one of the scopes instead of a fixed ring. I bought 2 Primaluce Lab 115mm guiding rings which fit both a 102ED F/7 refractor and a William Optics Star 71 II. Alignment shouldn't be a problem anymore. The guiding rings seem to hold tight enough the scopes and the fixed rings still allows the tubes to tilt a bit, enough for fine adjustments.

The data for this one also was waiting to be processed. I hoped to get more for it, but it starts to get low and neither the clouds don't want to go away in December. So I call it enough for this season. This is a combination of HOO + RGB. I wanted to shoot again RGB with a new refractor, but the newtonian data is all I had for it. Lately I enjoy more RGB colours with narrowband data to enhance it, but I'm posting some intermediary RGB, HOO and starless HOO images too. And the astrobin link: https://www.astrobin.com/umkbwp/ Clear skies! Alex

Thank you all so much! I will process one day a simple HOO combination too. For this one I tried to keep all the stars in the image. They can distract the eye from the nebula even though they're a little reduced.

This is one of the first targets I shot and was happy with since the beginning of my astrophotography journey Almost 4 years later, I decided to shoot again this nebula, this time with better gear and traveling to darks skies for most of the data. Even though it resembles the old image's colours, this new one is more accurate from the real colours point of view. Most of this nebula is made of ionized gases which emit light at certain wavelengths. Most of the emission of the hydrogen comes out as deep red, whilst oxigen emits a blue-green light mostly. But, besides the emissions in this area, the region here contains also dark nebulae (dust blocking the light behind) and reflection nebulae (easily visible at the trunk's tip). Named by its appearance in visible light as Elephant trunk, it is also described by many as a lady with long hair seen from the back. This whole region spawns over more than 3 degrees on the sky at over 3000 light years away. In comparison, the moon seems only 0.5 degrees wide. Another star in this show (pun intended) is Herschel's Garnet star, or Mu Cephei, the brightest star in the image. It's about 100000 times brighter than our sun and it's also one of the largest known stars. Its radius is larger than the orbit of Jupiter around our Sun. I started capturing data for this image early this year and ended this summer. I shot 2 panels in order to capture the whole area and I exposed more than 40h in total. I've been quite inactive lately unfortunately. You can watch the image at full resolution on astrobin or on Flicker. And the old image here.

Hello! Can you post some pictures of the setup? Unless the OTA's a lot shorter that it used to be in the beginning, there must be something misplaced in your setup. Though, reading your description, it seems correct. My ED72 is the first iteration and I'm having difficulties to achieve focus, but the other way. I found that the proper distance with the dedicated corrector is more than 55mm. Adding ~5mm doesn't allow me to reach focus due to lack of inward travel. I knew that newer versions OTAs are 10mm shorter than mine in order to accommodate a 10mm wide rotator, but it's possible that newer ones are even shorter?! The distance between the focuser and the lens cell is ~198mm for my OTA.

I'm installing/removing the OTA(s) with the gear switches unlocked to prevent any accidents. I suppose you could do that with the switches locked if you are very careful, but I don't want to take any risks. You should aim to balance the whole system so well that the scope doesn't rotate by itself unless you push it by hand. The bearings are so smooth and allow the mount to rotate so easily compared to the SkyWatcher mounts, there is virtually no chance to forget to re-engage the switches without noticing.

1. I don't know, I never used Polemaster, but I heard that it about or exactly the same. If I had direct visibility to the NCP area, I would first use the iPolar, then recheck and readjust with polar drift align. 2. Yes, it's irrelevant with platesolving. 3. As far as I know, the worms are made of brass and the worm wheels of brass (or read somewhere steel, but I don't find this information on iOptron's website). As far as you don't push anything too hard, I don't believe there is any issue if you keep the gear switches locked, but accidents can happen.

You can read my review about the GEM45 and also about tuning an AZ-EQ5 mount here: Or about my experience with darkframe To summarize, the GEM45 exceeds my expectations in how is performing. With about 10kg of short scopes, it still guides <0.8" total RMS. Depending on seeing, it can even stay below 0.6" total RMS for most of the session. I'm disappointed by the software and mounting the head on the tripod. And you need to be very careful with handling the mount. On improving the HEQ5, I would not expect miracles from tuning, though I heard about some excellent results for others. I know that that just wasn't the case for me. On the other hand, there are plenty of tutorials on how to disassembly the HEQ5, you can order yourself new bearings and new worms and replace them. I ended up spending more on my AZ-EQ5 than to buy a new GEM45 and the GEM45 tracks and guides so much better. Until now, at least. Here's a typical guiding graph for the GEM45. Not the best, not the worst.

Hello, Neil! I don't think there's such a thing in the SkyWatcher mounts, except for the EQ8 with absolute encoders. I've been less active lately and missed the activity on this thread, but I answered to Hadyn on PM for his question. I'm attaching to the thread too a video of the washer/clutch case. Alex 20201031_142646.mp4.74c708b9bffa5984567ed6914da60ca7.mp4

It seems that I got less active lately in this hobby, mostly due to the pandemic, directly or indirectly. However, I'm planning to move from where I'm living now in the close future so I started replacing my gear with lighter and better items. One of the items was the mount. I still have a tuned SkyWatcher AZ-EQ5 and a stock SkyWatcher EQ6-R. I used both quite a lot, I passed with them long time ago 1000h of exposure. And recently I bought an iOptron GEM45. The AZ-EQ5 is in the lightweight mount class, but performs quite poor for astrophotography. The original RA worm was a crappy one and I sent the mount to DarkFrame for tuning. I received it back the same, I only lost time and money. I then purchased 2 new worms from China via OVL with some help from FLO. The new one (I didn't test both) have a larger PE than the original one, but a smoother one. The p2p PE of the new worm results in a >60" deviation. When pointing close to the NCP, it guides well below <1.0" total RMS. When pointing towards the celestial equator, the performance drops significantly to 1.0"-1.8" RMS. I always need to use short exposures in PHD to guide it smoother. In total I spent for the AZ-EQ5 perhaps more than 1800 euros with the tuning, the new worms and deliveries. A lot pricier than stock in the end, but it still has 2 big advantages: mine came with a foldable (towards the mount) pier style tripod and it's light, I can carry the mount with the tripod folded in one hand. The mount and the tripod weight less than 15kg. The other advantage is that I can use the second saddle for the second scope. I used this combo more than a couple of times, with short focal length refractors and all went well. A SW 72ED + an ASI1600 + a finder/guider mounted as counterweight as close as possible to the RA axis, perfectly balances a SW Esprit 80 and a Canon 550D. The EQ6-R is a lot heavier mount. The head itself weights about 17.7kg, it has a handle, but even standalone it seems a lot harder to carry than the AZ-EQ5 assembled on the tripod. The 2" tripod for the EQ6-R weights about 8kg. Definitely I cannot carry both the mount and the tripod in a single trip for a longer distance. The performance and weight capacity are decent though. Mine has quite a large backlash on both axis, I cannot feel it at hand, but it's obvious when slewing at slow speed. It doesn't bother me for imaging, anyway, since I balance the mount a little east heavy. At most I put a single 200/1200 newtonian and camera on it or a dual setup consisting of a 150/750 newtonian and + a 102/714 refractor and camera, one on top of the other. Weight was not an issue, but a larger momentum + wind affected the guiding performance a little. Towards the NCP it guided excellent at 0.4"-0.6" RMS, but closer to the celestial equator, the performance varied and dropped for this mount too. On Orion, at times the guiding stayed below 1.0" total RMS, but many times it went worse than 1" total RMS. I believe that I never put a scope on this mount and looked through it, I only used it for AP. One thing that bothered me for a while was that the mount was stalling at times due to insufficient power. None of my domestic 12V power sources that I used for the AZ-EQ5 was good enough so I used a 15V 8A source to power the mount. I recall paying around 1300-1400 euros for the mount about 2 years ago. I used the SynScan app on Windows to drive the SkyWatcher mounts. The app mimics the functionality of the hand remote. The AZ-EQ5 doesn't have a polar scope and I believe I never used precisely the polar scope on the EQ6-R either. The app allows you to perform a 2/3 star align, then it figures out the polar error and you can then perform a polar alignment routine aided by the software. You can select a star for polar alignment, slew to it automatically after select, align in center, then the mount moves a little and the software tells you to adjust the altitude and bring the star in center, then it moves again and tells you to adjust the azimuth and bring the star in center. Simple as that. If you're way off initially with the polar alignment, you might need to realign once or twice again. The SynScan app + drivers are also much simpler than the EQASOM and can be used for controlling the mount from other programs via ASCOM or for pulse guiding. Now, to the more recently acquired mount, the iOptron GEM45. I spent a lot of time researching what mount would suit my needs. Lightweight, good performance and not astronomically expensive. After many reviews read for the CEM40, I decided to go for the GEM45 as both share the same components. I only saw CEM60's and the older 45 eq. All my astrofriends' CEM60's perform better and more consistent than my EQ6-R. The GEM45 is supposed to have a PE resulting in an error less than 14" p2p. The graph for mine says that it's less than 10". The first thing that I noticed when I received the mount it was how small the box it came in was. The mount head is light at about 7kg and the tripod 5-7kg. The second thing that I noticed was what a poor design was made for mounting the mount's head on the tripod. It is unbelievably stupid compared to the SkyWatcher mounts and it's horribly difficult to mount and tighten the mount on the tripod in dark and cold. Again, comparing to the SkyWatcher, a minus is that you always need to disengage very carefully the gear switches and never leave them engaged. The mount does not have a friction clutch as the SkyWatcher has and hitting or pushing hard the components can lead to damaging the gears. So the mount seems very sensible to handling, it requires a lot of care and mounting the telescope(s) on the mount while holding the CW rod with the other hand can be quite damn hard sometimes. However, there is no backlash. After setting all the hardware, the next thing was to connect the remote control + the software. It was clear the day I received the mount. It arrived at 5PM and at 8PM I was out of the city with all the software installed. The iPolar was easy to use, however, you need to connect a separate USB cable for this, the mount does not have a USB hub. You can perform a star align from the hand controller, but not from the Commander app. You can perform a polar iterate align from the hand controller, but not from the Commander. Speaking of star alignment, if you choose a 2 or 3 star alignment procedure, I was used to the fact that the first star can be way off when initiating the alignment. The SkyWatcher mounts' software (hand controller or PC app) took into account the error and corrected it for the next stars. iOptron's software (hand controller only, the PC Commander can't align at all) does not. So you need to search again for the second (and third) star to bring it into the view and center it. Only then the model is taken into account. Moreover, the polar iterate align is a pain and, surprise, the polar iterate align and a retry of star alignment after polar adjustment does not take into account the model it computed at the previous star alignment so all the stars are way off if the zero position is not set very accurate. Searching automatically for zero position seems rather a poor joke. So, after being used to the SkyWatcher software, the iOptron seems soooo limited and counterintuitive. Due to this, I had quickly to learn to drift align with PHD when Polaris isn't visible (it my the case at home on the terrace). Leaving all the poor engineering and software designs, things are getting better. The mount looks very nice and rotates around both axes very very smooth. You can also pull cables through the RA and DEC axis and have them available at the DEC saddle. There's only a USB 2.0 connector on the saddle, that was rather useless for me so I needed to pull a USB 3.0 cable. However, the 12V power available on the saddle is very welcomed to power the cameras' coolers. As I type, I'm imaging with 2 ~70mm refractors one on top of the other + 2 mono ASI cameras. Both scopes weight about 10kg. Guiding performance is always below 1.0" total RMS, ranging between 0.4" and 0.8" total RMS, regardless of the pointing position on the sky. If I manage to convince either the mount or PHD to compensate for the PE, I believe it should perform much better as the error increases to >0.6" only when the guiding switches from East to West or viceversa. Plus, being backlash free, it responses very fast to dithering commands and settles quick and, with the small refractors, it didn't seem bothered almost at all by a mild wind. In the end, I'm very happy with the consistent very good performance of the mount, but still disappointed by the mount attachment to the tripod and the poor designed software and alignment procedures. I'll come back with more reviews for cameras and telescopes that I own or owned. And images, after I manage to process them. I've more than 100h of data waiting in the queue to be processed. Clear skies and stay safe! Alex

If you have data covering the whole (or even wider) area, check this out: https://pixinsight.com/tutorials/multiscale-gradient-correction/

Thank you all very much! This is, in fact, only half of the original resolution. I also started thinking how to compose the multi panel images in order to fit better some more common ratios for printing. At 9260x8730 it should come out fairly large without overscaling the image. I'm currently shooting some R, not sure if it's worth it under the moon, but I don't expect much either. I'll see if I keep the data or not. It's been quite cloudy lately and very unusually cold. We should have 30C+ during the day, but it barely warms to 20C 😮 Not that I complain...

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/