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About Space_Plane

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    N. Ireland
  1. Hi Rich, Stumbled across this the other day on CN, a user there seems to have essentially written a book on pixinsight, maybe it'll have some helpful info? https://www.cloudynights.com/topic/680910-new-update-to-my-pixinsight-process-flow-posted-its-a-book-now/ Chris
  2. Certainly a strange one! From memory it was occurring no matter the exposure, 10, 30 or 60 seconds, and I wasn't guiding either. I see some minor diffraction spikes on the bigger stars from being stopped down a bit and oddly they don't seem obviously triangular. I'm out of ideas anyway, no clear nights for a while for any more tests, and I don't assume I can fix pinched optics in a lens Thanks again for your input.
  3. Many thanks @michael8554, I've attached one of the preview subs from that session, auto-stretched straight from the ASIair. Its a bit lower resolution but its particularly noticeable in certain areas. I can upload some of the .fit files later if you think that might help? Thanks Chris
  4. Thanks Roland, yes, it was bought new only a few days ago, 85mm F/1.4 AS IF UMC (if any of that helps!) Manual Focus. I was quite disappointed lol, I'm hoping its just something I'm doing wrong, but I've used multiple other (and much heavier) lenses with exactly the same setup and haven't had any issues like this
  5. Hi, Recently got a new Samyang 85mm 1.4, and as luck would have it, had a clear night to experiment with it on my asi178, attached via geoptik adapter. Did a quick smash and grab on andromeda after taking dozens of different exposures testing focus and how far to step the lens down. I'm relatively confident my PA & tracking etc weren't "too" bad. The attached png of the stack is 20x1min at f2.8, with nothing more than a crop at the edges and 1 set of levels to make the issue more obvious. Best focus I could get was just shy of infinity. All the stars are triangles! Any ideas? Chris
  6. Thanks for that vlaiv, was an interesting read (google translate helped me out a bit ) Certainly gives me lots to consider, and typically the lens has increased in price in a "sale" lol, so I have time yet to continue my research!
  7. Many thanks for the input everyone. I was never 100% sure vlaiv if a smaller sensor kindof, sits in the middle / "best" part of a lens and only the bigger sensors receive the worst of the aberrations at the edges, or whether the lens acts like a funnel and all sensors get all aberrations regardless of size. Fascinating Do you remember where you saw some test shots? I quite like the idea of it for the price, but the combination results in 5.82"/ px. Wasn't sure how badly that would affect images, maybe things would be a bit, blocky? Thanks again!
  8. Hi all, I have recently been looking at the Samyang 85mm and considering using it with an ASI 178. Has anybody got any experience with it? I know the 135mm is rather famous and well regarded, unfortunately also twice the price Thought this lens might be worth a try for the slightly wider fov and hilarious f ratio, and hoped maybe the tiny chip on the 178 might "skip" the worst of any potential edge of field aberrations? (if i understand that correctly). Cheers Chris
  9. I am quite intrigued by this, I always just assumed it had to be as close to infinity / spacing as possible, 'virtual' infinity is totally new to me ? Its similar lenses I have at present, all vintage takumars, 55, 135 & 200. When I was out briefly a few days ago it was the 135 I tested, and you're right, it looked about as best focus it was going to get between 1/2 and 2/3 of the travel. It still looked quite soft though, whether that's just how it is, or whether it would be sharper at more accurate spacing / infinity mark I don't know. Hopefully find out next clear night! Thanks
  10. Wow Vlaiv, that's an incredible amount of helpful and useful info, thanks for taking the time to go into so much detail! I'm really rather looking forward to getting to try all these things out, especially the .ser files and gain/exposure settings. Sounds like it'll make a lot of difference. Just need some clear nights lol ? Thanks again
  11. Hi Rich, That isn't something i've come across before, i'm fascinated. I've only used these lenses with a DSLR before, and it was really picky about focus / infinity. The slightest movement knocked it off. Due in part to larger sensor then i presume? I managed to get out the other day and experiment a bit, and with the adapters I have, was about 41.5 out of 44mm. The lens would vaguely focus about half way around the focus ring, but it wasn't great. I wasn't expecting ~2.5mm to make such a difference to the focus. Look forward to getting different extensions and trying to get it sorted a bit better. Cheers
  12. Thank you both for your comments and suggestions, its greatly appreciated! I must have slid the gain and exposure sliders up...and down....and up lol over and over, it mostly looked very blown out on screen, so just took a guess ? I'll try higher gain and lower exposure as you suggest, and certainly more frames, sounds good. Is there a benefit to .ser? I haven't tried it before. The initial images I took had loads of squares all over them at different zoom levels, which led me to debayering & pipp after some research. I'll look into bayer drizzle instead. Lots to experiment with! Thanks again!
  13. Hi all, Just a quick post after spending an hour the other night experimenting with my new zwo178mc-cool. I'm new to cmos cameras, new to pipp and debayering, new to autostakkert etc lol The following is 5 x 10ms images, 0 gain, 25 offset, roughly (and badly) focused by eye on an unbalanced 72ED-R / AZ-GTI I've a lot to learn but it was a fun first outing. Tips & criticism welcome ? Enjoy! Thanks Chris
  14. Hi everyone, Thanks very much for your info & associated discussion, and Rich for your offer. I'll have to read more into your suggestion Olly, i've never tried it. I wonder if i can make it work on my star adventurer ? I haven't quite decided what i'll do just yet, have to think about my spacing a little. The spec of the geoptik says 19mm, the backfocus of the 178 is 17.5mm and the potential adapter above is 5.5mm, for a total of 42 of I believe the required 44mm? Not sure how to best deal with 2mm! I'll be using vintage lenses for now, but I think the m42 -> canon adapter I have will work ok here, seems to reach infinity fairly well on my canon dslr. Supposedly clear spells here over the weekend, might get a chance to start experimenting ? Thanks again Chris
  15. Hi all, I'm just starting down the path of imaging with a cooled zwo 178mc, and have hit a few bumps! ? I purchased a geoptik canon-ccd adapter as I'm planning to use it with short focal lenses for now. Any ideas how best to align the sensor..."squarely" to the adapter, for easier framing etc? Maybe its not as big an issue as I assume? I've seen the following T2 rotation adapter which I think I'd just about have the space for. Anyone ever used them or know if they work ok etc? Any advice & suggestions welcome ?
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