Search found 146 matches

by mAnKiNd
Thu Sep 13, 2018 12:55 pm
Forum: Deep Sky Imaging
Topic: sticky exposure length or sticky gain/offset for sky-limited exposures?
Replies: 41
Views: 5669

Re: sticky exposure length or sticky gain/offset for sky-limited exposures?

Thanks Brian, Dialing in offset is indeed important, I ran into the same issue once where I didn't have any offset and my calibration frames did not work properly either. I noticed on my last run of the smart brain analysis that it automatically pushed my offset value to max, perhaps to avoid this s...
by mAnKiNd
Thu Sep 13, 2018 12:24 pm
Forum: Gallery
Topic: IC 5070 Pelican Nebula
Replies: 6
Views: 1216

Re: IC 5070 Pelican Nebula

Hi Dave, Thank you for the taking the time to explain your workflow, which sounds like textbook procedure and surely leads to great results, as you've demonstrated :) I can only add comments from my experience and hopefully I can be of help. I've followed a similar workflow as yours as well when tra...
by mAnKiNd
Thu Sep 13, 2018 1:42 am
Forum: Deep Sky Imaging
Topic: sticky exposure length or sticky gain/offset for sky-limited exposures?
Replies: 41
Views: 5669

Re: sticky exposure length or sticky gain/offset for sky-limited exposures?

oopfan wrote:
Thu Sep 13, 2018 1:17 am

I've decided that my next challenge will be SHO of a part of the Soul Nebula, specifically here.

My sensor's FOV closely approximates hers. It's nearly exact in the vertical dimension but my width is wider.

Brian
That sounds awesome! Go for it :)
by mAnKiNd
Thu Sep 13, 2018 1:41 am
Forum: Deep Sky Imaging
Topic: sticky exposure length or sticky gain/offset for sky-limited exposures?
Replies: 41
Views: 5669

Re: sticky exposure length or sticky gain/offset for sky-limited exposures?

Brian thanks. It's my understanding that if I were to use the smart brain (whose exposure setting analysis is based by default for a 1 hour stack) to figure out the best exposure & gain for each channel, say to achieve max. dr, then with that 'equilibrium between channels' in place, one could simply...
by mAnKiNd
Thu Sep 13, 2018 12:52 am
Forum: Deep Sky Imaging
Topic: sticky exposure length or sticky gain/offset for sky-limited exposures?
Replies: 41
Views: 5669

Re: sticky exposure length or sticky gain/offset for sky-limited exposures?

Or perhaps simply just use the smart brain on each channel for finding the max DR sky limited exposures, acquire calibration files and simply stop looking for unified settings, base it all on total integration time.
by mAnKiNd
Thu Sep 13, 2018 12:45 am
Forum: Deep Sky Imaging
Topic: sticky exposure length or sticky gain/offset for sky-limited exposures?
Replies: 41
Views: 5669

Re: sticky exposure length or sticky gain/offset for sky-limited exposures?

..though I'm not sure how one could keep the narrowband channel at the same exposure & gain/offset as the RGB channels and still get a decent single exposure histogram. Perhaps, treat the narrowband channel differently. Max DR for LRGB channels and a higher gain for the narrowband channels. If it's ...
by mAnKiNd
Wed Sep 12, 2018 10:45 pm
Forum: Deep Sky Imaging
Topic: sticky exposure length or sticky gain/offset for sky-limited exposures?
Replies: 41
Views: 5669

Re: sticky exposure length or sticky gain/offset for sky-limited exposures?

I always liked the idea of keeping gain, offset, and exposure the same. Not only do I get to reuse darks but I also get to set the exposure based on maximum light using the luminance filter. Having a full-well depth of a mere 15000 electrons makes me painfully aware of accidentally saturating stars...
by mAnKiNd
Wed Sep 12, 2018 9:58 pm
Forum: Deep Sky Imaging
Topic: sticky exposure length or sticky gain/offset for sky-limited exposures?
Replies: 41
Views: 5669

Re: sticky exposure length or sticky gain/offset for sky-limited exposures?

It is also important I feel to ask what do we define as our target in our optimised livestack? Is it a target SNR value? Bit-depth? Or is it not empirical and simply an aesthetic judgement?
by mAnKiNd
Wed Sep 12, 2018 9:53 pm
Forum: Deep Sky Imaging
Topic: sticky exposure length or sticky gain/offset for sky-limited exposures?
Replies: 41
Views: 5669

Re: sticky exposure length or sticky gain/offset for sky-limited exposures?

I've read about people keeping gain and offset the same. Some people opt for keeping the stack size the same and adjusting exposure, and others who keep the exposure the same and adjust the stack size. They are equivalent but keeping the exposure the same allows you to use the same darks. Brian Ind...
by mAnKiNd
Wed Sep 12, 2018 9:48 pm
Forum: Deep Sky Imaging
Topic: sticky exposure length or sticky gain/offset for sky-limited exposures?
Replies: 41
Views: 5669

Re: sticky exposure length or sticky gain/offset for sky-limited exposures?

Having said, it is often recommended to vary gain/offset and is often done in imaging techniques, for example, Mr. Rista and others wrote many times on the CN forums about using the following gains for the ASI1600: L: G50 O50 RGB: G75 O50 NARROWBAND: G200 O50 ...all of them sharing the same offset s...