Stacking subs from different cameras

[RickS (Rick)]

I'm experimenting with stacking OSC data from a QHY-12 together with LRGB data from a SX-H18 using a mixture of tools (Maxim, Registar, CCDStack and PixInsight so far). The results are starting to look promising. Has anybody else done something similar? I'd be happy to receive advice from the wise I'm also happy to share what I learn if anybody is interested...

Cheers,
Rick.

[jase (Jason)]

Hi Rick,
Indeed, I've performed various levels of data scaling before to produce a composite image from different focal length instruments. When a opportunity arises that I can reuse data previously collected, I tend to opt for downsizing a luminance to match a wide field image. I have also done the opposite, but only with chrominance data. Luminance data being upscaled tends to lose its resolution if not done carefully. If you have a quick search on data scaling / upsizing on these forums you'll see some of the results I've produced. Happy to answer any questions you may have.

Cheers

[RickS (Rick)]

Thanks, Jase. I'll check out the threads on data scaling. I'm sure they will be illuminating!

I'm using two different cameras on the same scope and image scale is only a little different. The main challenge I'm having is trying to get some consistency in the colour.

Cheers,
Rick.

[RickS (Rick)]

Originally Posted by RickS

Thanks, Jase. I'll check out the threads on data scaling. I'm sure they will be illuminating!

And they were Some great pics of the Cat's Paw and M83 too.

[jase (Jason)]

Originally Posted by RickS

I'm using two different cameras on the same scope and image scale is only a little different. The main challenge I'm having is trying to get some consistency in the colour.

Thanks for checking those out Rick.

If you're not working with huge differences in image scale, I would have thought the process would be relatively simple. It gets more complex after registering if you need to shrink or bloat stars in order to match a layer. Upscaling colour will introduce noise so blurring will combat the issue.

The two tools of choice for getting colour consistency between two images is the curves tool and channel mixer in photoshop. The curves tool can be used just like any other non linear stretch function but selecting specific channels provide brute force work. For finesse work, the channel mixer comes in. Here you can determine what shade of red is required by mixing in variations of blue and green for example. Very powerful. There are other tools out there. Depends on what you wish to achieve.