yes, it is possible. I don't like it very much because of the difference of visibility of each night and centralization in the FOV. It demands much processing effort.
I thing that maybe I haven't camera to get good image of this galaxy. I have good resolution: 0.8 arc seconds, but when I call the faint information, the stars become more fat, and I presume all the other thin details.
Perhaps a CCD with similar resolution, instead of CMOS, will capture the faint details with more sharpness.
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Bumping up to ISO1600
Not only noise issue. I have problem with light pollution as sky glow. With 1600 the time of exposition must be small.
With small (7.3' x 1.2') and faint objects the sky glow is the worse occurence. It merges with the object.
I think that with much more low ISO subs I wil get better result than high ISO.
Its magnitude is about 11 - 13, but with galaxy this is relative. Galaxy isn't nebula. The interior details are very small and with very little difference of magnitude.
yes, it is possible. I don't like it very much because of the difference of visibility of each night and centralization in the FOV. It demands much processing effort.
......
Well, not that much effort really. I just copy one image, paste it on the other (which creates another layer), use the opacity slider to blend and the move and rotate tools to register. Easy.
I just copy one image, paste it on the other ... move and rotate tools to register
I stack with DSS, I don't know about any ressources do move and rotate in it. The best way is to adjust the position before start the capture. I can let the camera intalled to don't need adjustment of rotation, but perhaps some adjust of RA or DEC will be needed.
When I tried this mode of capture - multiple night - I hadn't possibility to let all ready between the days. And the more difficult to adjust was rotation.
You called my attention: why do you (me) don't try again, since you (me) have the ease of stationary equipment ? Will you (me) be traumatized with past experience ?
Yes, at that time I lost almost 1 hour by adjusting the position. But, now, it isn't the case ! I will do !
What I do is to refer to a sub from the previous session...I use a copy on my phone/tablet...and attempt to match the rotation of the camera with what I did before. Sounds clumsy, perhaps, but I took a second batch of subs of M42 this past weekend and after stacking the two sets of subs I found I needed to crop the scene by a total of 200 pixels in each dimension. Not perfect, but I can live with it
With an obsy I'm sure it'd be more easily reproducible. As for the weather...it can change enough in one night that it may or may not be a bad thing! I found in my two sets of subs (taken 2 months apart), that the fwhm for the subs are distributed about the same.
I'm still learning of course, refining my technique, enjoying my 1100D
There is another issue with rotation of camera. At least with my focuser the camera can stay with different inclination. What this cause ? Distortion of field.
I had problem with it. When the left side of the photos where well aligned, the right side isn't. And vice-versa. Normally at the periphery.
Stacking all photos in DSS or merging multiple results from stacking different groups of photos, the result was the same: I needed crop the image to eliminate the side with misalignment.
As I said, today I have the telescope and camera assembled full time. This and those prior problems are off. I must return to try multiple nights and ... why not ? ... mosaics, again !
, I reckon MANY more hours ! This galaxy is very faint and small. Perhaps only with a clear and black sky, distant from any light polution.
