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alanjgreen

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About alanjgreen

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    Cumbria. UK
  1. alanjgreen

    c8 edge collimator

    Make sure your sct is property cooled. Set up early and let in acclimatise before you use it (especially if you store it in your warm house). Image quality is affected by warm air inside the tube. - I had a scope coat that I used to put over mine in case of a shower or birds! FLO sell TeleGizmos scope covers for SCTs. - then you can get setup before dark and leave it to cool. Dont go mad with magnification. UK atmosphere affects image once you get over x230 ish usually. If fine focusing is an issue consider upgrade to a feathertouch micro focuser with two speed focusing (best accessory I ever bought for my c11). If you go for external Crawford focuser as an alternative then remember the extra weight at the back will impact balance. A Micro focuser will not impact balance. Alan
  2. alanjgreen

    c8 edge collimator

    Firstly, buy some stainless steel bobs knobs to replace the dodgy collimation screws, you dont want to be messing about with a screwdriver in the dark - FLO sell them. https://www.firstlightoptics.com/bobs-knobs-collimation/bobs-knobs-celestron-8-edgehd-collimation-knobs.html Then (and only when you C8 is properly cooled - after at least an hour outside) do a STAR TEST using minimum x200 magnification by defocus a medium brightness star - Polaris if you can see it - and check the circular diffraction rings...) - if they are circular and concentric then you are collimated (make sure the STAR IS IN THE CENTRE OF THE EYEPIECE) - if they are not concentric then you need to TIGHTEN the screw opposite the tightest patch of rings by a TINY AMOUNT (one eighth or one tenth of a turn) - recheck the results of the tiny adjustment IMMEDIATELY (make sure you re-centre the star before checking the results). If its improved then go a bit more, if its worse then undo what you did and try another screw! - if the star is not in the centre then the results will be inaccurate! Here is a guide: https://www.astromart.com/reviews-and-articles/reviews/beginners/show/eds-guide-to-sct-collimation Buy the Bobs Knobs now but only fit them when you have confirmed that collimation is needed via the star test. If its okay then leave the knobs "in stock" until you need them When replacing the three collimation screws do them ONE AT A TIME and make sure the C8 is HORIZONTAL so nothing can drop on the primary mirror. You also have the option to REMOVE the secondary assembly from the scope then nothing can drop onto the primary. Fit the knobs while having plenty of soft bathroom towels underneath in case of any drops! Once you have collimated for the first time, then its easy! 1. Just make sure you finish with all three screws/knobs TIGHT. 2. Only do the collimation when your scope is properly cooled. 3. Make sure you use an eyepiece that provides at least x200 magnification for the best results. HTH, Alan PS. A visual check of SCT collimation state can be done in the daytime. If you lock the scope horizontal then remove the front cover. Now stand back 5 meters and get your eye level with the centre of the scope. Look into the front of the scope and you should see nice concentric circles like this... If not, then you can do a ROUGH COLLIMATION by turning the knobs to get the concentric pattern seen above!
  3. You would be wasting your money, that's far too much magnification for the planets, image will just be blurry with no detail. For Jupiter and Saturn you need to try a range of magnifications from 125-200x to get the sharpest view. The sharpest view will be with the planets appearing small in the eyepiece. They are a long way away and will never be big in the eyepiece Its almost impossible to get a sharp image of Mars so it can take more magnification, up to 300-350x. Magnification is calculated as scope focal length divided by eyepiece focal length. I think your scope has 2050mm focal, so the 13mm is giving around x150 which should be fine for Jupiter and Saturn. 10mm eyepiece would give around x200 and above that you are likely into blurry images unless the nights atmosphere is above average. You could try the standard Baader mark IV zoom (without Barlow) this would let you tune to the sharpest view (more important than size) but I would forget the zoom barlow, when combined with the Baader zoom it's way too much magnification for your C8 scope. Alan
  4. alanjgreen

    Astronomik 2" Hb (H-Beta) filter for sale

    Now reduced to £95 plus £5 special delivery next day insured postage.
  5. alanjgreen

    Nebula Filters

    I've owned and used Astronomik, Castell and Skywatcher. They are not all the same. The Skywatcher OIII was fine until I got an Astronomik OIII to try, it showed the Skywatcher to be terrible, it's been in my loft for 4 years, I can't bring myself to sell it to someone else. The view through the Astronomik is so much MORE - more nebula and more stars to make the field more pleasant and natural There was absolutely no comparison! The skywatcher UHC when compared to the Astronomik UHC I then purchased to replace it was less bad but still no match for the Astronomik. I now also have a 1.25" Castell that I use with binoculars and this seems fine for that purpose. I have not compared it directly with the skywatchers as I can't face using them again. If your budget allows Astronomik then pick up a 2nd hand one and save a few quid. There was a 2" UHC on astrobuysell earlier in the week. They are scratch resistant and have a 10 year guarantee! You do get what you pay for! - Shop around as prices vary, Modern Astronomy and Widescreen Centre seem to be about the cheapest places to buy Astronomik filters if Astronomik is way over budget then grab the Castell from 365astronomy, they are good value for money for sure. Alan
  6. alanjgreen

    Wanted: TeleVue Ethos 3.7mm SX eyepiece

    Looking for a used TeleVue Ethos 3.7mm SX eyepiece. It must be in excellent condition and have the original TeleVue box and end caps. Willing to pay up to £300 (excluding postage) for the right example. I would also need to see photographs of the actual eyepiece before agreeing a deal. Send me a PM if you have one that you want to sell... Thanks, Alan
  7. Ha Ha Ha, you're right Still Big Dobs chance will come once the Milky Way swings around a bit more to be better placed from the shed. Main thing is that (1) cooling is no problem with the Borg and (2) I can get down to the southern horizon easily too, for instance last night I managed to pick off M6 for the first time with night vision, it was small but clearly a Butterfly! M7 was stuck low behind my shed so probably need another month before it clears it to pick that off. Shows that one scope is never enough...
  8. Date: Sat 9th June 0020-0215 Scope: Borg 89ED f6.7 (fl 600mm) on SkyTee-2. Night Vision: PVS-14 with Photonis 4g INTENS. Eyepieces: 55mm (f3.2 x11), 35mm (f5 x17) Filters: Astronomik 6nm Ha CCD. Introduction We are now into June and up here in Penrith that means no darkness and about an hour of “deep dusk” before the sky brightens once again from 2am onwards. To the North the sky never goes dark at all. This creates about a 2-hour observing slot where at least I can see the main constellation stars to enable me to use the red dot finder to align the scope to something in the sky. Start Low… I had the 55mm Plossl and 6nm Ha CCD filter loaded together with my PVS-14 Night Vision Device (NVD) attached to the eyepiece with the TNVC/Televue afocal astronomy adapter. This turns my Borg into an f3.2 scope with a magnification of x11. The NVD provides a 40 degree field of view (fov). I’ve had three sessions on Sagittarius since late May and last night after an initial alignment on Antares and a pan around the low summer targets (Lagoon, Triffid, Swan, Eagle) revealing that wet sky conditions low down were rendering the view inferior to previous sessions, we had had heavy rain around 4pm and the sky still remained in a wet state. …Then Aim High! I decided to re-align to a new target area of the Milky Way around Cygnus (higher in the sky). I used the red dot finder to align to Deneb and started to move down using the SkyTee-2 slow-mo controls until I found the North American nebula which was bright and showing its whole structure. It was just slightly bigger that the fov of the eyepiece so I had to use the manual controls to investigate. I discovered a whole wispy section moving off the north side of the nebula that I did not know was there. Having spent many years looking at these targets with much larger scopes, it’s hard to really comprehend how easily they are seen with tiny aperture when you add Night Vision and a decent Ha CCD filter into the equation. Sitting to the left of the North American was the Pelican, the vertical streak of its “beak” was clearly visible alongside two other straight sections, and it looked like an “F” rotated at 45 degrees to the right. There was plenty more nebulosity on view but this basic “F” shape kept catching my eye. At the edge of the fov I could see a curvy section just off to the left of the Pelican (IC 5068) and centred it to observe it. IC 5068 appeared brighter than the Pelican and seemed to make the shape of an “opened palm of a hand that was holding the Pelican in place in the sky” Next, I opened the clutches of the SkyTee-2 and changed to “nudging” the scope by hand to see what other shapes I could “discover”... Below the North American, I bumped into a “backward C shaped nebula” (near 68 Cyg) which was almost large enough to fill the fov (Sh2-119). This nebula was less clear than the others observed so far but still easy to see. I headed back to Deneb to start a pass into Cygnus. As I found Deneb, I immediately noticed three spread out patches of nebulosity, two were small and circular while the third was a longer streak of nebula (Sh2-115 & Sh2-112). I panned right into Cygnus. Wow, there is just so much nebula! I ended up doing a “grid sweep” style manoeuvre with the scope as I panned and stepped my way down through the Cygnus region. The star attraction was the thick black lane section around Sadr which was bright and beautiful. But there was so much more nebulosity than “just this Sadr bit!” The clouds of shape was varying in brightness and density and the size of the area covered was HUGE. Sh2-108 stood out brightly. At one point I happened upon the Crescent nebula, it was pretty small but bright and showing the full curve (at x11) around three bright stars. Now it was time to head left over to the Elephant Trunk and Sh2-131. I returned to the North American nebula first then used this to get my height correct as I panned left and eventually straight into the sh2-131 nebula. It appeared as a large fuzzy “brain” to fill the whole fov. The centre section was much harder to see and appeared as a “dark hole within the surrounding fuzz”. I could see several black lanes coming and going within the nebulosity and used the nearby Garnet star to try to orientate myself with Sky Safari. I do not believe that I saw the Elephant trunk within the nebula but there was plenty of darker “black bits” at other locations within sh2-131 (using a mirror diagonal was also adding confusion to my brain! [I hope to get it later in the season when I get the 20” mirror and NVD onto this target] I panned up from sh2-131 looking for Sh2-129 (Bat wing nebula). It was easily located but was pretty faint compared to some of the other nebula that I had picked out so far. I panned down from IC1396 and located Sh2-132 which appeared as a bright patch of nebulosity. A quick look at Sky Safari revealed that the Cave was nearby so I used Sh2-132 as a marker to pan left over to the Cave (sh2-155) and soon bumped into it. I have never seen the Cave region with such low magnification before so the view was hard to recognise! The nebula was a nice size within the fov but there was so much nebulosity that I found it hard to see “just the usual bright bit”. There was a “clear dark side” to the nebula but the nebulosity’s appearance was more of a “cloud” or “cauliflower”. I tried switching to the 35mm for more magnification but the loss of focal ratio caused some of the brightness to be lost. By now, it was starting to get light and the sky was brightening, I decided to head for the Bubble nebula. I can only imagine how tiny it must be at x11 as I never managed to locate it! It was time to pack up. I returned to my eye piece box to discover standing water on top, the dew was really bad! Sky Safari Flight Path Here are some screenshots from Sky Safari with my observing list highlighted Conclusions Writing this report has been a discovery in Sharpless objects! Most of those mentioned in the report are new to me and I have had to spend time using the internet just to find the names for the objects that I observed. It is clear that there must be very few nebula beyond the reach of NV (if they have a Ha component that is) and I am looking forward to getting my big dob onto some of these tiny faint Sharpless objects (for some increased NV magnification). However, it seems Sky Safari do not expect anyone to see these objects as it’s been a real pain to find the names this morning. Looks like I need to “search” for each Sharpless in turn and add them to an observing list to get Sky Safari to show them, a job for the next rainy day. Clear Skies, Alan
  9. And the winner is....... me Thanks FLO!
  10. @mapstar You may have missed this report? I was using Big Dob with military Night Vision and got to target the Crescent with a 6nm Ha CCD filter. The view of the Crescent was "unbelievable" when compared to last year (without night vision and Ha filter) which had been a decent view but Ha brings out nebula to a completely new level of in-yer-face boldness. I am looking forward to the Milky Way making its swing over the top ... Alan
  11. Astronomik 2" CLS Filter for sale This two inch CLS visual filter is in excellent condition and comes supplied with its original Astronomik case (see pics). See https://www.firstlightoptics.com/astronomik-filters/astronomik-cls-filter.html NOW SOLD
  12. 1. With the feedback received, I will cease posting images in my observing reports 2. I shall continue to post observing reports as I refuse to be bullied off this forum! Clear skies, Alan
  13. Certainly the Lagoon looks similar. The swan is not the same. I was on much lower power and the swan looked more "V" shaped with the rest of the nebula being far greater in size. I really did not recognise it as the Swan, which I have seen many times before with high mag in a C11 and it was a different view and feel altogether. I would say the Eagle was similar but with more head and outer wingspan areas. Next time out, I will get the 27mm Panoptic out for more magnification and see what I get. My hands were cold and I was wearing gloves so I stopped changing eyepieces at this point. You would probably get more of the outer nebula by sticking with the high speed of the 55mm. It's a different view at each speed used... Alan
  14. I have never viewed the stated Sagittarius targets in the big dob but I have for example viewed the Crescent nebula with the 6nm Ha filter in big dob and the difference in brightness is HUGE. The Crescent was better than an image, so bright and so much detail, plus the long focal length of big dob gives me scale too. I can only assume from my own personal use of NV that these Sagittarius targets would move to another level with all the extra brightness and scale on offer from big dob. The detail would be astounding I am sure. The smaller aperture and smaller focal length offers a wider field of view and this is where I struggled with big dob the other night on North American nebula and Gamma Cygni - they are just too big! You may have a very bright image but you cannot get the whole nebula into the view. I have viewed all Sagittarius targets in a C11 SCT and I can say that the M16 Eagle for example was a "puff of dust" at best. The M8 Lagoon was too low to get more than a black lane between two bright patches. Now we are into a whole new ball game... I am lucky to have the best of both worlds. Alan
  15. Date: Wed 23rd May 2345-0245am Scope: Borg 89ED f6.7 (fl 600mm) on Sky-tee2. Night Vision: PVS-14 with Photonis 4g INTENS. Eyepieces: 55mm (f3.2 x11), 35mm (f5 x17), 27mm (f6.5 x22), 18.2mm (f9.6 x33). Filters: Baader 610nm Red, Astronomik 6nm Ha CCD. Moon: 68% First Light: Borg assimilated into Black Ops Astronomy (Night Vision) I have owned my PVS-14 Night Vision monocular now for about a month and so far have concentrated on the climax to galaxy season by viewing the biggest galaxies in an attempt to see as many spiral arms as possible before the sky rotates them away and the darkness disappears. All my usage so far has been with my 20" Dobsonian. With my old enemy, the Moon, also now spoiling my dark skies, it was time to get out the Borg89 and deploy some filters to defeat the moon. Proof of Concept I had setup around 9pm to make sure my red dot finder was aligned with the scope (at least the Moon is good for something ), and to test reaching focus with the Televue 55mm Plossl which needs loads of out-focus! I have been using a short 150mm tube on my Borg as I had previously been using it with Binoviewers. I have screwed an extra 50mm tube into the main scope body but even with the draw-tube fully extended, I could only reach focus by lifting the 55mm Plossl eyepiece about 5mm up & away from the diagonal (Luckily, it’s a click-lock diagonal and capable of holding the eyepiece firmly even when lifted). With the initial testing completed, I moved everything back inside to wait for it to get dark later... Always Have a Plan The plan for the night was in two parts (1) grab some Globulars & Galaxies to familiarize myself with the new setup and then (2) move onto the Milky Way later when it swings into view. Part 1: Find some easy Globulars and Galaxies I was using a manual mount (sky-tee2) and Sky Safari 5 (on ipad) where I have field of view circles on screen showing me what I should be seeing in the eyepiece and allowing me to manually jump around the sky using “2 circles up and 1 circle right” type of movements. M13 – With the 55mm Plossl (x11), M13 was easily located and a tiny fuzzy ball was seen. I added the Baader 610nm Red filter which helped to darken the background but it was only when I switched to the 27mm Panoptic (x22) that the outer stars of the globular started to resolve and a decent view was had. The Globular was still tiny in size but accepting smaller scale is part of the price of "Black Ops Astronomy". M51 – I moved onto the Whirlpool. After messing about on my knees with the red dot finder I got the scope to the right area and quickly located the double galaxy at the eyepiece with the 27mm & 610nm Red filter still loaded. I was impressed to see hints of a circle surrounding the galaxy! I upped the magnification to x33 with the 18.2 DeLite but the background became much darker and although the image scale improved, I felt the circle of arms was less visible that with the 27mm. (The Night Vision device is f1.2 so it responds better to faster scope speeds, scope speed is increased by using longer focal length eyepieces – I have added some spec detail to the top of this report). M51 – Right time to increase the speed. In with the 35mm Panoptic and 610nm filter. Now there was a definite circle of spiral arms twinkling around the tiny galaxy (x17 magnification). The bridge to the nearby NGC was not seen. Finally, I moved to the 55mm Plossl (x11) and was surprised to see a tiny circle surrounding the galaxy. Seems incredible that you can pull out arm structure at x11 with a 68% moon nearby! M101 – Onto M101 nearby. With a bit of faffing I finally got the small-ish hazy patch centered. It was still a decent size in the 55mm with 610nm filter but with no detail seen within. I decided to remove the 610nm filter “just for a laugh”. The galaxy became brighter with fleeting glimpses of what looked like a circle arm structure (similar to M51) but thicker/chunkier. This structure was only glimpsed with averted and much concentration but an astonishing result really considering the Moon and tiny magnification. Part 2: Exploring the Milky Way I used the red dot finder to centre the scope on Antares which was pretty low to my southern horizon but easily located. M4 – I had the 55mm Plossl loaded with no filter. When I looked in the eyepiece I could see a large bright well resolved patch of stars next to Antares. “What’s that?”. Consulting Sky Safari, it was M4. It appeared much larger and more resolved than M13. I have never viewed M4 before (it’s too low for my Dob from my Obsy/Shed) so that’s a new Messier for my list! M80 – I navigated over to M80 which turned out to be a disappointment after M4. It was just a tiny fuzzy star at this low magnification. Right, onto the main event. I decided to just pan up through the sky until I bumped into some Nebula. I attached the Astronomik 6nm Ha CCD filter to the diagonal. M17 Swan – 55mm. The first nebula that I happened upon was M17. Although, I did not recognize it as M17. I had to consult Sky Safari to try to work out what I was looking at! (I have viewed the Swan many times and I know what it looks like – or I thought that I did until now. Wow!) It appeared as a white hot upside down “V” surrounded by nebula on all sides (So much more than the usual “tick”). The familiar circle of nebula to one side was there if you looked but it was lost in the full (previously unseen by me) nebula structure. M17 – 35mm. Image scale improved and a second lovely view of this nebula. Maybe it was slightly dimmer with the loss of focal ratio but memorable for sure. (this is the nearest image I can find to what I saw) Now, knowing where I was in the sky meant that a quick pan over to M16 Eagle was next… M16 Eagle - 55mm. “I can see an Eagle”. What more can I say, it looks like an image! I can see the head, the outstretched wings and a very bright body. M16 – 35mm. "I can see the Pillars of Creation". Admittedly, they were tiny! But black gaps in the bright body are there. Never thought I would see them and definitely not with an 89mm scope! (this is the nearest image I can find to what I saw) What could beat that? Well, I only had a few minutes to wait before I stumbled onto the M8 Lagoon nebula. Wow, that just beat the Eagle nebula hands down. I was mesmerized! The view was so good that I am struggling to find an image on the internet to match the view! M8 Lagoon – 55mm. Wow, the nebula is so bright and thick that it stands out and punches you in the face. It looks like you are looking into a swirling black hole. Plenty of variations is brightness within the thick nebula help to give the view real depth. M8 – 35mm. The detail is breath-taking, lovely long dark lanes revealing lovely shapes and structures within the very bright nebula. I could not tire of this view! (this is the nearest image I can find to what I saw) M20 Triffid – 55mm. Seen in the same field of view as M8. It was a poor second to the Lagoon mainly due to its small physical size at the eyepiece (Remember this is x11 magnification). However, the 3 pronged black lanes within were clearly visible. M20 – 35mm. View much improved with larger scale. Lost some brightness from the nebula due to loss of focal ratio but the inner detail was easy to see. (this is the nearest image I can find to what I saw) Beaten back by the Dew I moved onto Cygnus and the North American nebula but the view seemed poor in comparison to what had come before. This surprised me as I can see the bright North American nebula naked eye at x1 magnification using Night Vision and a 1.25” Astronomik 12nm Ha filter. A quick look with my torch down the front on the scope showed that the Borg had succumbed to Dew Final Thoughts I had a great night. The view of the Lagoon will stay with me forever! The weather is set fair here in the UK so I know that it won’t be too long before I get outside again. I still can’t get over the fact that Night Vision can defeat the Moon. I live in a dark place, SQM 21.6 and when the Moon is up then I am forced to stay indoors – NOT ANYMORE! Clear Skies, Alan Note: The images that I added are not mine. They are the closest I can find to what I saw, although I only observed them in black and white (no colours) but with varying shades & brightnesses in-between.
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