One day at a time - Image processing

[Tailspin45]

Off topic, but my daughter asked how big M42 is. I told her about 9000 solar-systems-wide, She asked how big is the solar system. I told her to go here, and she loved it.

[Tailspin45]

I probably overlooked it but... why are you using sharpcap?

Accident of birth? The beat of a butterfly wing creating a chaos effect?

I have a cheap Windows laptop that is my astronomy machine (formerly my microscope machine).

SharpCap recognizes the weird (but inexpensive) SvBONY SV-305 CMOS camera I have, and both got good reviews. And SharpCap runs on my machine, so...

But I'm always open to alternative views, and willing to change my preferences.

[JayTee]

Hey Tommy, et al.

This is a great topic with important information but it is beyond the scope of the beginner's forum. Because of this, it has been moved to the (of all places) image processing forum.

Cheers,
JT

[Tailspin45]

Well, I guess I’m flattered, but I’m sure a beginner.

When I started down this road I wish I’d had the advice of those who have contributed here.

Will other beginners look elsewhere for advice on this?

[JayTee]

Will other beginners look elsewhere for advice on this?

You bet they will, plus having your post in the correct forum helps with the search function within these forums.

You may feel like a beginner but this topic is pretty advanced and is now where it always should have been.

Cheers,
JT

[Tailspin45]

Here's proof that astrophotography post-processing is an art. All these images were produced from the same six frame 90-second stack saved as a FITS file.

I don't think any of these images is particularly good...just different.

[Tailspin45]

Okay, my best and final offer(ing) on this dataset / image stack.

Processed with StarTools, post-processed with Lightroom.

The core is still blown out and my light-pollution filter took out the characteristic green hydrogen leaving mostly blue oxygen.

I guess I should just title this Orion Nebula (M42) Emphasizing Oxygen as if I meant to do that all along?

[Tailspin45]

Thanks to Ivo Jager, of StarTools for the education. I had it completely backward.

When it comes to coloring, in the visual spectrum, Oxygen-III is a teal green, H-alpha is red and blue is usually just reflection nebulosity.

He also warns that SharpCap does a number on files and isn't suitable for proper post-processing.

I am now on a hunt for a new package. Will report back.

[UlteriorModem]

You may have overlooked it but I did ask why you were using sharpcap.

[Tailspin45]

You may have overlooked it but I did ask why you were using sharpcap.

I saw your question and replied that it recognizes my camera and, “ But I'm always open to alternative views, and willing to change my preferences.” Now I wish I’d known why you asked.

[Tailspin45]

Finally had a clearish sky last night. Quick and dirty first look at a stack produced on the fly by SharpCap.

Lots more work to do with the 22 folders of raw FITS frames. (BTW, macOS Observatory really helps organize everything.)

More accurate color than my last effort, I think, thanks to light-pollution filter and more careful post-processing in Lightroom. Happy to see the Trapezium instead of a blown-out blob.

Didn't do an alignment other than to point the mount more or less at Polaris, so sub-images all had to be short. This is 80 500ms exposures, no darks or flats.

Meade 114mm f/5 reflector, SvBONY SV-305 camera.

[Tailspin45]

Weather has precluded capturing a new target, so I've spent the last three weeks trying different image processing packages and have settled on StarTools.

Went back and re-stacked 792 (68m 34s) raw RGB24 (don't ask) M42 frames, saved the result as a 32bit FIT file and went to work on it with StarTools.

Workflow:
Autodev
Crop
Bin (50%)
Wipe
Autodev (redo) with core as ROI
Sharp
HDR
Color
Decon
Life
Stop tracking, denoise

Used Lightroom to tweak the tone curve a very small amount (lights +19, darks -6).

[Ruud]

Plenty nebulosity in this one and cheerful colours too.

[Tailspin45]

You may have overlooked it but I did ask why you were using sharpcap.

So why did you ask? Now that I know how it works, I like it a lot.

You seem not to like SharpCap. Why? I'm eager to know if I'm overlooking something.

[Tailspin45]

Plenty nebulosity in this one and cheerful colours too.

I tried very hard not to prejudice the color rendition throughout the process. I was using a UHC filter for light pollution which certainly affected the results, now that I think of it.

[UlteriorModem]

Sharpcap is typically used for planetary .avi or video capture. In fact it is what I use when I do planetary. I don't know of many whom use it for DSO.

But it appears suitable for your methods so good for you

[Tailspin45]

Sharpcap is typically used for planetary .avi or video capture. In fact it is what I use when I do planetary. I don't know of many whom use it for DSO.

I'd love to know why it's not favored for DSO. As a novice, it seems to handle longer exposures just as well as shorter video captures.

And I do like the helpful ancillary tools.

Do you (or anyone) know of a discussion or review that will educate me on the relative disadvantage of SharpCap for DSO?

[UlteriorModem]

No not really. Frankly I did not even know you could do DSO with sharpcap!

I don't know the program all that well to be honest, as I said I have only used it for planetary. There is no 'disadvantage' that I am aware of.

[JayTee]

SharpCap's direct competitor (price wise) is Astro Photography Tool (APT). Apt is the low-cost leader for DSO imaging software. It would be cool for you to download the full-feature free version of APT and give it a try out and see which one you like better. Here's the link: https://astrophotography.app/downloads.php

Cheers,
JT

[Tailspin45]

It would be cool for you to download the full-feature free version of APT and give it a try out and see which one you like better. Here's the link: https://astrophotography.app/downloads.php

Will do, thanks. I think tried it but have learned a lot in last few weeks and will have a different perspective I’m sure.