rotatux

Nice M1... I personally struggled to frame it (too weak and too small) last year in my H-LP sky and abandonned, so that's some achievement Oh and question about your HH+Flame: what filter did you use ? your colors look like what I get with my UHC...

You definitively have some valuable data in that sub : Some nebulosity and nice colors. Your sub is not that much overexposed, I would say it's reasonnable, so that was your stretching. You will do better focus / tracking next time, learning one step after the other (live view focus, exposure settings, stacking, etc.).

I wish I had my first at it that good Though that's strange all your stars are already burnt at such low ISO, did you use RAW or a cam-produced JPEG ?

While zooming you even get the start of a hint of the Flaming Star Nebula. I like this subject, already had a go at it with an old 135 last year, but being a smaller frame it was more on the center part and only catched the top cluster. Not sure I will have the night to retry it this year :-/ You say 75mm and F4.5... is it a prime or a zoom ?

Do you mean you're tracking by hand, following a star in the cam ? I know this can be done in theory, but achieving it... wow I find the image does not reward your efforts as it should, maybe using shorter subs (and 16bits!) in live stacking could help avoiding trails and enhance final quality. (just a wild guess)

I'm about to flock my tube too, but just a question BTW: is there any risk the flocking material could accumulate water / humidity, and raise condensation, during moisty nights ? or do you combine it with some heating device to avoid it ? PS: what I actually have for flocking is a somewhat thick felt (I mean maybe equivalent to ±15 sheets of paper)

I don't know your equipment and capture settings (how many subs / overall minutes etc), but it's beautiful. Sadly my FoV is even narrower with the MFT sensor, but I'm planning to take about the same framing (which should just fit in the diagonal) with the help of my now stabilized mount and CC-reducer.

@ neil : in your first one it was color-less and quite difficult to distinguish fuzzies from stars, so I much prefer your 2nd for its color and easiness to read. @ nigel : in fact I prefer your first one, which despite less natural (but still good) colors I find more constrasty. You catched nice structure. Still annoyed by that mottling effect (of your processing software?) when zooming in. /Myself must wait for another try at this target with my new cam (since last year) and tightened mount... you lucky, I yet have to find the right cloud-dispersing magic wand Edit @ neil : strangely your 2nd image shows the same mottling effect on the background than Nigel's... same software ?

Thanks for kind comments. Yes I quite like the edge-to-edge consistency of this lens (no coma!), as much as I hate its color-diffraction pattern (BTW no tool for this yet under Linux, I tried generic deconvolution as a wild guess but I must still learn how to use it). For reference, here's the page about tightening this mount: http://nexstarsite.com/Reviews/NexStar102SLT.htm#AltAxis (the last paragraph especially helped IMO).

Here's first output from my session of sept. 22. I got out nearly all night with my Alt-Az mount and a bunch of lenses to test. It's also first light since I tried to fix my mount by tightening hardly the altitude gear as advised by some page on the net; Hopefully on this one it managed 40s exposures with a high keep rate, which it had never achieved yet (whatever the focal). This one is not really a test any more, as I now know what to get of this lens. I let it uncropped so you can appreciate the FoV given by this setup. Thanks for watching. M31 - Andromeda Galaxy Details: Gear: Olympus E-PL6 with OM-Zuiko 200mm/4 at F/5.4 and TS-Dydimium filter on Celestron NexStar SLT Capture: 60 lights (/80% keep) x 40s x 3200 ISO, 13 darks Sky: average (didn't get any SQM, was prb 18-19), 50km from Paris, France Processing: Regim, Fotoxx

You don't tell about capture conditions, so as I wild guess, your star elongation looks approx. perpendicular to the direction of image center. To me this looks more like field rotation, maybe mixed with a bit of coma in angles. About tilt checking during the day with the cam train on, just a rough idea: maybe focus on a the vertical face of a far building, and check focus along a vertical line on live view ?

Don't be discouraged, I too face a mount that doesn't want to be stable enough more then 20-30s (more often 20). My keep rates vary from 22 to 80%, so you're pretty up the score I think if you would read back this thread it would be somewhat the same for others. You're on your way. Nice image, you caught much nebula. However I find it's strangely too noisy given the high number of frames you stacked. Maybe you had to stretch very aggressively ? What ISO were your subs ? Did you shoot low on horizon ?

Here's a last-half moon from last month (this one fullsize, contrary to my gallery). First try at video-like stacking with a proper burst shots sequence. Auto white balance then added some contrast and color saturation. To my surprise some color differenciation appeared, so quite happy with it This was without Barlow, now I'm just wondering for next try whether I should do 130PDS+barlow or 127MAK ? Optically I prefer the MAK, but the focuser and camera coupling is much better on the 130...

Here's some planetary for a change: 2 sample shots of Saturn taken on 2017-06-11. Details: ~120s FullHD @ 30p movie crop mode, Olympus E-PL6 with Celestron 127MAK/1500mm and x3/x2 APO Barlows on NexStar SLT, processed with cvastroalign. (indulgence requested, I'm still learning how to process planetary footage and use cvastroalign) Edit much later: realized this is not in the thread's subject (not DSO), I should not have posted here. Oops :-/