WolfieGlos

Evening All ! Skipped this section 5 months ago, so thought I'd come back and say Hi to all! Currently a year into my astro journey, started slowly with my DSLR and lenses and no tracking...slowly progressing upwards with the equipment...and the editing and learning the software to do so. 73 images to date, and have learnt a lot so far and enjoying it, and I wonder how much more I will know this time next year! First successful image was NGC 7000 last December with a 200 f/2.8, August was IC 1848 with the Evostar 72ED, and I have recently got back from an overdue honeymoon to Australia, and of course just had to capture some Milky Way shots whilst there! Couldn't believe how much I picked up with a Full Moon in the sky, stock camera and no tracker....and luckily a wife sleeping after a very long day! 🤣 Hopefully shows my progress to date, always open to comment/criticism on my images. Noise and tilt seem to be my biggest enemies.....well, other than the dreadful UK weather.... Look forward to joining in more and gaining/imparting knowledge! Chris NGC 7000 - Canon 77D + EF 200mm F/2.8L II, f/2.8, ISO 800, 200x 20s light frames, stacked in DSS, edited in GIMP and Starnet++ IC 1848 - Canon 800Da + Evostar 72ED @ 420mm, f/5.8, ISO 1600, , 257x 90s light frames, 61 darks, 52 bias, 71 flats. Stacked in Siril, edited in Siril, Starnet V2 and GIMP. Milky Way over Uluru - Canon 77D + EF-S 10-18mm @ 10mm, f/4.5, ISO 1600, 40x 20s light frames, 8darks, stacked in Sequator, edited in Siril and GIMP.

A little late to the party, but I use the same scope, and DSLR and a star adventurer. Attached is a picture of my setup (yes, the camera was upside down!!) SW 72ED + FF + Canon 77D / 800Da, Baader red-dot sight, ZWO ASI120MM Mini + 30 f/4 guidescope. This literally **just** balances in RA, with the SA counterweight at the end of the shaft. The only way I can balance it, is putting the guider onto a ballhead at the bottom the SA bracket. If I mount the guider on the scope, it will not balance....short of buying additional weights! I do not use a longer dovetail for this, just the standard one supplied with the 72ED scope. It even falls just right to enable the red-dot polar illuminator to stay mounted. My weak point is definitely the tripod, it's fine for the weight limit but the legs are a bit flimsy when extended. Polar alignment is an issue for me as well, particularly with my tripod. What I do now, is polar align in the scope but then I do NOT turn on tracking. What I do next, is locate my target by altering RA and DEC and then note down the marking on the date graduation scale. I then rotate the clutch back to enable polar alignment, then align and turn on the SA. I then carefully rotate back to the same date on the circle.....and voila. It's not perfect, but it's pretty close. I then just check to make sure the polar alignment is still OK. I generally guide for between 2-4 minutes with no issues, but have done 10 minutes with a 300mm lens.

Thanks 😀 It was tracked on the SA 2i, so quite easy to image the Moon. When the UK weather sorts itself out anyway... And agreed on the portability, but I only image DSO's with a guider. So something for the OP to bear in mind if wanting portability and possibly expanding to imaging.

I've had the SW 72ED since April, used purely for imaging. Despite collimation issues in the corners, it's been a good beginners scope to me. I imaged the Moon 2 nights ago with a DSLR, single shot between the clouds. Cropped and enhanced with Siril wavelets.

I have a stock 77d and a modified 800d; both have articulated screens, wifi and the same sensor. The wifi works well for me, but it is a bit of a chore to get an image off of the camera, to the phone, to upload to astrometry to platesolve. Got my modified camera from astronomiser, http://www.astronomiser.co.uk/ . From the point of order, I had it in under a week. Superb service, highly recommended.

Well, I'm back and the weather here in the UK is beyond terrible. I ordered the Astrodymium tilt adjuster before I left, I had 1 shot on Friday, which I tried without the adjuster and got 21% tilt. After that single frame, it clouded over....and rained. So then Saturday, as it was clear despite the forecast saying otherwise, I decided to just have 1 go with the rotater, and see what happens. Wasn't even fussy about where the raised edge would be. I added the 0.2mm thickness adjuster between a 5mm spacer and my T-ring, aimed at the same target as the night before......and I got 5% tilt on a test shot. As it was clear, I decided to stick with it (Ring Nebula, so a massive crop on the image anyway)..... and I got varying results of between 5-10% tilt during a 1 hour session...so massively improved! That put's me at circa 60mm backspacing. Next time we get a break in the clouds, I will keep the same camera angle/rotation but try different targets to rotate the scope a bit more and see what it gives me. I'm tempted to refine it, but on the other hand...I'm also tempted to stick with it !!!!

Hi Sien. Glad you managed to get a better result than me, usually I’m quite a patient person but not on this it seems! That’s at interesting topic you’ve linked there, quickly skimming it, it looks promising. Interesting you say about mosaics, that’s not something I’m considering for a while yet, but if the stars are in 1 corner only, could you just keep the eggy stars on an area of overlap? I didn’t get to test that device from FLO even though it arrived in time. I’m now away down under for 3 weeks, hoping I can catch the Milky Way whilst here, but keep us updated if you try the tilt adjuster or Astrobin guide 😊

Hi @Sien, erm, sadly not very well!! That first night when I had the scope back was near perfect. I should have left it alone, but I tried varying ranges of spacers and camera rotations and I am back to square one, with tilted corners varying from 15-25%. Annoyingly in the same corners as previous. I’ve also purchased an Astro modded dslr; a canon 800d which has the same resolution as my stock 77d, and I get the same problem in the same areas of the image. So I know it’s not the camera and FLO fixed a problem in my scope, and so it must be in my imaging train somewhere. I didn’t try going up to 60mm backfocus, I stopped before then as it got worse the more spacing I added. But to be honest, I’ve given up trying to fix it for now and I’m accepting eggy stars in the corners and cropping the worst parts out. Not the result that I want, but I also want to image rather than waste clear nights solving problems! Funnily enough I saw this today on FLO’s homepage showing new items, which I’m going to order and see if this finally sorts it out. There’s also an M48 option, but I’ve queried with FLO and the M42 option fits over the threads on the stellamira flattener. https://www.firstlightoptics.com/adapters/astdym_m42_tilt_adjuster.html I have clear skies predicted later this week so I will test it if I get it before Sunday, but otherwise I won’t be able to test until the end of October 🙈 What have you been trying to remove the tilt and eggy stars?

Hi Sien, Yes, using a field flattener 🙂 Agreed it's not best to rely on just the software, but I could see the eggy stars for myself. I do usually crop the images, but a full frame shot (i.e. M31 will fill my entire frame) will show up the problems. It's been a while since we were posting above, but an update on what happened to me. So I was in constant contact with FLO support about this, and in the end to their credit they actually took the scope back under warranty to have it checked over. I now have it back, and whilst I haven't been informed exactly what was wrong, it did require adjustments and correcting, and is now working very well! 😄 Whilst I have only just had it back and have used it so far for only 1 nights worth of imaging, my tilt value is very low (varies from 2%-8% across 150 subs....MUCH better than previous 25% and higher). But this new reported tilt value may also be off slightly due to backfocus, as I can see eggy stars in the far corners. I have a 5mm spacer added already, and it looks like it needs more as the streaks are inwards, so I will be continuing to alter this in the coming days with the predicted perfectly clear skies we have here (and typically a near full Moon......). But if the report from the ASTAP software is showing the below values with incorrect backfocus, (Siril gives a very similar reading too) then (in theory) improving the backfocus should make the corners better and lower the reported tilt. However, if this is the worst tilt that I get from now on, then I'm happy!

I’ve recently been through a similar route, having started nearly a year ago, although I started off with a stock DSLR and a few lenses. I still use these so can’t comment on the Astro camera route, but that is probably my next decision on expenditure; modified dslr or Astro camera. I started with the Star Adventurer 2i, and still use it, and the only thing I would add is that if the Samyang lens doesn’t come with a lens collar then definitely get one, as that will allow you to rotate the camera and frame your target. I would then mount it onto the Star Adventurer L bracket, and don’t bother with a ball head as it will always move even slightly. I then added guiding to my setup, and recently a short refractor, the skywatcher 72ED, and it works great (collimating issues aside). Depending on the size of scope you eventually want to upgrade to, you don’t necessarily need to upgrade the mount; it’ll work fine for longer lenses and small scopes * with guiding I would add * The weakest part of my setup now is the K&F camera tripod I have; it’s rated, apparently, for 25kg but it wobbles like jelly when higher than 1 (of 3) click of the legs. It means I’m currently kneeling on a gardeners knee mat to polar align etc, so maybe look at getting the skywatcher tripod which you can buy with the Star Adventurer, it will be a lot more stable from the outset and will be better suited for a scope in due course.

Hi Lee, I hope so! I feel like it's been a long time, a lot of testing and tweaking. Not helped by the late nights at the moment either haha. I have a stock Canon EOS 77D. Correct, it is supposed to be 55mm for the Stellamira too and I started out with no spacers albeit with the standard 72ED push fit and a faulty t-ring which wobbled. These have since been replaced with a screwed fit and a Takahashi T-ring, which has no give in it at all. On my first target (using the original push fit and faulty t-ring) with the 72ED, which was M51, it reports a 63% tilt in ASTAP and actually looking at the individual subs it is quite clear that the stars are very eggy, and to me ASTAP is reporting it correctly. As M51 was cropped quite a lot it's hard to see it in the final image (which I'm quite happy with!), but it is there, and without cropping it is very evident and from the star patterns suggests the backfocus needs increasing. That's why I have been adding spacers. Since I have been trying to collimate, I could actually try removing all spacers as well and see what that does.....thanks for that thought, will give it a shot and see what happens. But at the moment, my subs definitely show eggy stars, not so much of a problem if I'm cropping the image down like above, but a full framed target (i.e. Andromeda, NA, Veil nebulae, etc) will cause me big problems. The below test image from Markarian's Chain shows it quite well with only the very extreme edges cropped off. Not a great image as it doesn't have many frames but taken as an example to see how bad it would be on a full framed shot. The individual subs report anywhere between 45-58% tilt, so similar to M51 above. When Andromeda rises into view again I intend to frame it diagonally from corner to corner to make it fit, but based on the below it won't be great. The bottom right corner is so bad the stars appear out of focus.... I would almost be forced to do a Mosaic. Markarians Chain was the last one I took with no spacers, push fit and faulty T-ring, I got into contact with FLO afterwards who have been VERY helpful, and since those items were replaced (and spacers added) the tilt values and eggy stars have reduced but they are still evident. I'm convinced it's in the focuser so will continue with it, I guess you're right, perseverance will get me there in the end. Cheers, Chris

Thanks @Sien and @AstroNebulee @Sien - I measured along the length of the tube on the side with the thread showing and the opposite side from this, and it was between 1-1.5mm difference. Assuming a perfectly accurate measurement along a tube I'd guess that that's pretty reasonable (?) and probably within tolerance at this price point. Interested though in what you say about moving the lens, given that it is screwed in I had assumed it would be square and the problem couldn't lie here, but will take a closer look at mine now. Well, just an update on an "interesting" week learning about collimating...my word, what have I got myself into 😬 I ordered a collimator (not a starguider like you have Lee....but it arrived in the same "Next Generation" box and the same instructions....must be an Amazon special !), and it was fractionally out, so I made a v-block and dug out the rubber blocking access to the screws. Just digging the rubber out, the screws got altered and this sent it MILES out of collimation. After several hours trying to fix it, and getting it to about a 50mm diameter circle, I dropped it and it broke !! So I ordered another one, and this seemed like it was collimated out of the box when I put it into the scope (I didn't test it as it arrived late in the evening, and I had clear skies...), and I also got a set of longer spacers, so did a test with 5mm spacing, and then 5mm spacing after collimating with the new laser, and below are the results... ......in other words, broadly the same result even if the tilt has flipped from one side to the other, and slightly less percentage of tilt reported by ASTAP. Next up, I thought to actually check the new collimator, and found that whilst the laser dot was small in the scope, when projected over a longer distance the laser became a huge line instead of a dot....I then discovered a manufacturing fault had placed the washer inside partly over the laser!!! Unbelievable. So that's going to be returned, but for some reason, I tried the one that I broke previously.....and it was working again! After FAR TOO MANY HOURS, I managed to reduce the original laser to about a 12mm diameter circle, which is what it was to start with (!). By this time, it was pushing 11pm and clear skies again, so using my printed target, I managed to set the laser to rotate on the inner most ring (theory being, the centre of the laser should be in the middle of said circle shown below). Even if its slightly off centre from where I think it should be....it should get a better result in ASTAP. Right? And the result? With a slight change of backfocus to 4mm..... ........exactly the same. What a time consuming and frustrating week, other than knowledge gained I have literally got nothing better to show for it. Other than the dark circles under the eyes from the late nights 🤣 Still a bit unsure on the backfocus. I tried adding a 10mm macro extension tube prior to this, and it resulted in the star pattern for being too far away, and now by reducing it I have gone the wrong way so will try increasing slightly on my next attempt which may be midweek now looking at the forecast. At least I know it's between 5-10mm spacing, but I think the backfocus is also being thrown off by the curvature/tilt, since the same RAW file shows eggy stars in the bottom left+right, slightly in the top right but they are spot on in the top left. I'm also going to have to try collimating the laser to be even more accurate, but it's requiring so much time to reduce the circle and requiring the absolute tiniest of turns on the screws now. I find it amazing, that a device sold for accurate collimating.....needs collimating itself. Surely they should be sold pre-collimated....🤷‍♂️ Clear skies! Chris

That’s what my Canon 77D has, it’s annoying that you can’t programme multiple bulb exposures. I ended up getting a Pixel Wireless Intervalometer from Amazon, have to say it’s worked flawlessly over the last 7 months. You mount the receiver onto the hotshoe and connect with the supplied cable. It’s still on the first set of batteries and controlled via a remote. I usually set it running 30-45 minutes of images, then go outside and check the alignment etc is still ok, but you can set up to 999 photos from to be taken. Also quite handy after a batch of images, if the clouds have rolled over for a bit I put the cap on the scope and take darks until it’s cleared up. Another option if you have a Star Adventurer like me, is that you can get a cable that connects it to the camera and is in turn controlled via the app on your phone. When I was starting, the cable was sold out everywhere so I looked for other options and never looked back .

Cheers Lee, I’ve got one in order so will give it a go. Agreed on our weather! I had clear skies here all day and evening…within an hour of setting up the scope at 11 last night…clouds everywhere! Even the Moon disappeared!! For what it’s worth I did get some form of rings (within the star shape) and the blue halo around it appeared uniform in the centre of the frame, but not anywhere else. But that may be curvature due to backspacing, so will await the laser and try from there. Thanks for the very quick responses, will report back hopefully with a good result! Chris

Thanks Lee. Out of interest, which laser collimator did you use? If it worked for you I’ll order the same one 😂 Elsewhere I was informed that both a Cheshire and a laser will not work for a refractor and I should instead line up concentric rings on a bright star going in and out of focus. I don’t appear to have any slippage, I’ve never noticed any when focusing, and I have just checked out the mechanism and all is really tightly screwed in so this seems to be ok. I believe my issue lies in the focuser attachment to the tube, ever since the scope arrived some slight OCD on my part never liked how the tube ring wasn’t square to the focuser…I checked this out the other day, and the end of the focuser doesn’t appear to be square to the tube ! I thought it was in the rings, but you can just see a part of the silver thread in the picture. I’ve tried removing it from the tube, but it’s rock solid and I don’t want to force it off. Doing my best to measure , it’s between 1-1.5mm out between each end of the tube. So hopefully I can adjust the 3 grub screws on the focuser to sort this out. Don’t Skywatcher check these before they get shipped 🤦‍♂️ Thanks Chris

Hi, First time post here! Glad I found this, as this is exactly the problem I am having too, and been trying to fight it for the past month or so. I just wish I had found this sooner! I have added spacers, changed the 72ED connection to a screwed fix and even a faulty t-ring which had a lot of play and deviation. My image train is M54-M48 Adaptor, Stellamira Flattener, spacers, DSLR, so it's Interesting you note 60mm backfocus...I have added 2.3mm so far and am running out of threads to screw the t-ring onto, so might need an extender in there too it appears. Having thought all along my issues were backfocus and tilt using the command in Siril, I finally realised the other day having downloaded ASTAP that I have curvature as well, and as everything is now screwed together....that it is probably in the focuser.....and this thread seems to confirm it, so it looks like I need to order a Cheshire now and see if I can sort this out. Just wanted to say thanks Lee for your threads linked here, very detailed and hopefully will allow me to sort mine out! How did you hold the Cheshire in the scope, as they typically seem to be 1.25" whereas the focuser is M54 / M48? Presume you have some sort of adaptor?