M51 - Lum only

[vlaiv]

Taken on 7th of May. I wasn't really planning to image this target, I was setting up new laptop with software and configuring everything and testing out focal reducer.

That did not go quite well. FR was plagued by tilt and stars were awful all over the field. I managed to configure most of software, but it turned out that my saved PEC file was unusable on new laptop. After much frustration I decided to relax with a bit of imaging, took the FR away from optical train and pointed scope to an easy target. Seeing was poor, guiding also (0.7-1.0" RMS), temperature rapidly changing - and focus with it, so I was not expecting much from the data. It turned quite decent after all.

Shot in red zone (SQM ~18.5). Total imaging time: 2h.

ASI1600mmc + IDAS LPS filter. 120 subs 60s each, x64 flats and flat darks and I've rebuild dark lib day after with x256 darks. Scope was RC8" F/8, image is binned x2 for effective resolution around 0.98"/pixel.

Calibration and stacking in ImageJ (Fiji), processing in Gimp 2.9.8 - just basic stretch and a bit of noise reduction. I kept it conservative this time - teaching my self not to push the data beyond what it can present nicely

Thanks for looking.

 

[cuivenion]

Nice image, just to let you know the official release of GIMP 2.10 is out now.

[Rodd]

That looks pretty nice for being plaugd with gremlins.  I found myself in the same situation a few days ago--the part about not expecting to shoot this target.  I got a few hours of Ha for future use (Moons was up).  I think this image is going to be great.

Rodd

[vlaiv]

40 minutes ago, Rodd said:

That looks pretty nice for being plaugd with gremlins.  I found myself in the same situation a few days ago--the part about not expecting to shoot this target.  I got a few hours of Ha for future use (Moons was up).  I think this image is going to be great.

Rodd

Thanks Rodd.

This image was captured in the part of the night when gremlins went to bed . They plagued me prior to that when I was trying to setup everything and when I was testing focal reducer. Shooting of this image went more or less as usual - only thing that I can object was changing seeing, poor guiding (not sure if lost PEC is to blame or the fact that mount was sitting in basement for past 6 months and may need a bit of touch up and tweak) and rapid temperature drop probably causing focus shift. I did refocus at one point without paying too much attention to focus precision - I just saw that stars become a bit tighter so I concluded that it was a good move.