I captured this on 7/26/22 at Monkton (Bortle 3-4). Turns out capturing it was much easier than processing it! I reduced the stars in this image but I think it could be processed much more elegantly than I've done here. I'd be thrilled to hear how others have minimized the stars in their images.
AT60ED w/ field flattener
ASI2600MC Pro (OSC camera)
SkyGuider Pro with guiding via ASIAir Plus using an ASI120mm mini and a 30mm F4 guide scope
Optolong L-Extreme dual-band filter (H-alpha, O-III)
300 second exposures x 20, with dark, flat, and bias calibration frames
Stacked in DSS and processed in Photoshop
Hi Greg, another wonderful image, thanks for sharing all of these and taking the time to share the details of your captures as well. Helps others starting up and with the same equipment. I'm glad to see this because I have the 2600MC (traded in my asi071mc) and was using it with my 11" edge. Given it's slow speed, I thought just capturing color of the galaxies is going to be good for me. I haven't tried it with the Optolong filter yet.
A couple of places to do star shrink in photoshop. There are a set of tools called DSLR_Tools (I think Noel Carboni wrote them). They get loaded into actions. I find the Shrink Stars very useful. These are inexpensive tools. If you want cadillac functionality in photoshop then get to know a guy named Russell Croman who writes superior filters for photoshop. One of them Gradient Xterminator does a better job than similar filters in other tools to get rid of color casts or gradience in your images. It's one of the most used by the ASTRO-images.
Now, after many years, he's just published a couple more: StarXterminator (removes stars) and StarShrink (does what you want). They are superior solutions, but a bit more expensive. Just look up Russell Croman to find the reference. I think rc-astro.com, and look under his resources tab. Best of luck!
Terri
@terri Thanks for the suggestions, Terri! I've tried Starnet++ (v2) on this stuff but it does leave quite a bit of artifact behind and requires some cleanup. I will definitely try Star Shrink to see if it's any better. I also bought Gradient Xterminator and I think it does a nice job, although I have to say I haven't been too bothered by gradients of late using my ASI2600 in fairly dark skies. I also use the Astronomy Action Tools (from ProDigital Software; a.k.a Carboni's Tools) which works okay sometimes -- sometimes not. 😕
Thanks again, Terri!
Greg, seems like you're diving in with both feet maybe I can provide some feedback here (but remember the source, i am no AP expert). I think this image, while wonderfully detailed and colored, may have a gradient you're not seeing because your system isn't calibrated. It could be a bit of green I use a monitor calibration tool on all of my PCs/Macbook. Try RC on this image to see what comes. And of course it could be me as well.. Let me know if you don't want feedback (which is fine too). I generally want people to tell me when something is off so I can learn from it. And like all things, feedback is worth every penny you pay (smile). It looks the same on all of my platforms. Maybe a green cast, and if you have Pixinsight use SCNR or gradient xterminator and see what it does.. maybe good/maybe bad.
Terri
Greg, seems like you're diving in with both feet maybe I can provide some feedback here (but remember the source, i am no AP expert). I think this image, while wonderfully detailed and colored, may have a gradient you're not seeing because your system isn't calibrated. It could be a bit of green I use a monitor calibration tool on all of my PCs/Macbook. Try RC on this image to see what comes. And of course it could be me as well.. Let me know if you don't want feedback (which is fine too). I generally want people to tell me when something is off so I can learn from it. And like all things, feedback is worth every penny you pay (smile). It looks the same on all of my platforms. Maybe a green cast, and if you have Pixinsight use SCNR or gradient xterminator and see what it does.. maybe good/maybe bad.
Terri
Oh my gosh, the feedback is like gold to me, Terri! Please keep it coming (as long as you have the time to provide it). Eh, judging by some of the gorgeous photos you've done, you're an expert to me!! 😀 Yes, I must confess, I'm not using a very good monitor to process images and -- I'm VERY embarrassed to say this since I used to have a side business calibrating TVs and home projectors -- I haven't calibrated my monitor!
I'd love to try/buy Pixinsight, but it just seems like it's overly complex for me at this stage of my 'know-nothingness'. Haha...
I'll work on this a bit more. Thank you again, Terri!!
Greg, seems like you're diving in with both feet maybe I can provide some feedback here (but remember the source, i am no AP expert). I think this image, while wonderfully detailed and colored, may have a gradient you're not seeing because your system isn't calibrated. It could be a bit of green I use a monitor calibration tool on all of my PCs/Macbook. Try RC on this image to see what comes. And of course it could be me as well.. Let me know if you don't want feedback (which is fine too). I generally want people to tell me when something is off so I can learn from it. And like all things, feedback is worth every penny you pay (smile). It looks the same on all of my platforms. Maybe a green cast, and if you have Pixinsight use SCNR or gradient xterminator and see what it does.. maybe good/maybe bad.
Terri
Well, I made another attempt at this (STILL with an uncalibrated monitor, though!). I actually stacked and did initial processing in Astro Pixel Processor to reduce stars, but not remove them completely. I did a bit more processing in Photoshop and ran Gradient Xterminator and I think (?) it took away some green cast, but I'll defer to your calibrated monitor, Terri. 😀
The image is just so 'crunchy'. Is that the right word? I have a feeling I need a lot more time on this target to reduce some of that and get more SNR since I only had about 100 minutes of exposure on the nebula.
Greg
Greg, I only have a phone with me now but the color cast looks gone to me.
Terri
Greg, I only have a phone with me now but the color cast looks gone to me.
Terri
Thanks for taking a look, Terri! I pulled out my old X-Rite Eye-One Pro I used to use for TV/projector calibration but couldn't get it to work with Win 10. 😕 I ordered a Datacolor Spyder to replace it so, hopefully, I'll be able to recognize image casts a little more easily.
Thanks again!
Greg
Greg, the strong color cast is gone. Nice work!
Terri
