Practice on M101

[Brian]

Had a go at M101 last night. 50x30sec on my sony a6000 through C8 sct on a Celestron AVX. Guided with zwo 290 mini through a ct80. I took a handful of flats, darks, and biases.

I think the polr alignment wasn’t quite dialed so the dec tracking had errors of 4” at times so I limited exposures to 30 sec. Also, I have only experimented with calibration frames a few times. What I am puzzled by is that the flats don’t cancel the vignette quite right.

Advice and feedback is welcome!

[Don Quixote]

I am no AP expert so I have no advice. I just want to tell you I am enjoying your image. Thank you for sharing.

[Lowjiber]

Nice Pinwheel, Bryan!

Keep 'em coming, my friend.

Clear Skies

[STEVE333]

Hi Bryan - You have a nice start on this tough target.

Your processed image has the black level clipped so can't check it for vignetting.

If you can post a link to one of your Raw images both before and after Flats correction we can take a look at it.

Steve

[Brian]

Thanks Steve. I’ll post the raws when I’m in front of a computer.

[Brian]

So here are links to the master calibration images from DSS and also a stack without applying calibration:

Stack without cal:
Flat:
Dark:
Bias:

Advice on getting better calibration images is appreciated.

[STEVE333]

So here are links to the master calibration images from DSS and also a stack without applying calibration:

Stack without cal:
Flat:
Dark:
Bias:

Advice on getting better calibration images is appreciated.

Thanks Brian for posting these- Just going to a late lunch. I'll take a look later today if I can.

Steve

[STEVE333]

I didn't have any success Brian.

The size of the "Stack without cal" image was much smaller than the size of the other 3 Cal images. I Resampled it to make it match the 3 cal images, but, still didn't work. My "corrected" image came out with very strange colors. Not sure why.

Sorry I couldn't help.

Steve

[UlteriorModem]

So here are links to the master calibration images from DSS and also a stack without applying calibration:

Stack without cal:
Flat:
Dark:
Bias:

Advice on getting better calibration images is appreciated.

That's cool but the calibration files should be applied to each sub frame not against one that is already stacked

Any way you can publish the sub frames?