I was doing the Dynamic Background Extraction on IC434 and saw an odd artifact and was trying to figure out if it is an issue with the data or something else. I have the master Light then the sub after the DBE.
Can you let me know what you think? I can faintly see it in the master light as well.
- Scott V
William Optics ZenithStar 73, 0.8x Flattener, ZWO EAF, ZWO ASI120MM Mini Guide
Skywatcher HEQ5 Pro
That is really weird, my guess is that it's part of the data. The first thing I would try is stack the data using DSS and see if it's still there. WBPP can be a little tricky to use especially during the normalization stage of the data. Sometimes complex gradients can confuse the process if the settings aren't perfect. Let's try to eliminate that from the equation first and move on from there, re-stack with DSS. Also, did you dither between every frame when you collected the data? I am noticing a little bit of "walking noise" on the DBE example you processed.
Some people will argue that dithering is a waste of time however, that couldn't be further from the truth. The astrophotographer's motto is "Dither or Die". Experience will tell you dithering between each sub is the the easiest way to eliminate many problems with your data but it also needs to be done appropriately. If you did dither this time, then you need to increase the aggressiveness because there is obvious walking noise.
It's always a challenge to image such a faint object like the IC 434/B33 under this much light pollution. I am curious to get to the bottom of what caused that huge artifact in the center. Keep us posted. If we can't figure this out before next week maybe you can share your data and we can try to figure it out during our next AP workshop on the Wed Feb 1, 2023. However, I hope we can resolve it before then. Run the data using DSS and post the results.
Dan brings up some valid points. Calibration frames are a must. However, aside from that, drizzle can be very useful if employed while processing. Personally, I don't necessarily think drizzle is needed increase the size of the final image in this particular case however it can still be very useful while processing.
One more thing I should mention, I think you needed to be more aggressive when employing dithering since the walking noise is still evident in your image. What image capture software are you using? Do you know where to adjust the aggressiveness of your dithering?
Drizzle and dither go hand in hand. The other thing you must consider (which Dan mentioned), is drizzle creates a lot of extra files but if you have the space-time (get it, hehehe) go for it. Like I said before, drizzle only works if your dithering. In this particular case I don't think the dithering was setup up aggressively enough but I am still curious to see what will be revealed when it's employed while you process your data. Every single process will take that much longer because the file will be larger so don't think there is something wrong with your computer when you are working on drizzled files.
A good use for drizzle is to use while processing. Drizzle will allow you to increase the size of the image while you're working on it allowing you to get a good look at it the fine detail, then when your done processing it you can resample it back down to normal size.
Let's see what you get when you stack this with DSS. Don't forget to drizzle and fashizzle the nizzle.
If it still shows up after stacking your data with DSS then I would buy a kit to clean your sensor. Maybe it's something as simple as that?
I added dark calibration and flat frames. With just the dark frames, the spot is still there. With the flats, the spot was process out when using WBPP. In the flat frames I took, I see a splotch, so there is something in the optical train that I have to get cleaned out.
I attached a screenshot (left to right) of the WBPP with no calibration, WBPP with Darks only, and WBPP with Darks and Flats.
The attached flat (sorry for the green shift, it was just a quick way to view it in PI) shows the splotch.
Thanks for all of the support!
Good detective work, I think you solved your problem. Now you need to find out where the splotch is and clean it. It's so frustrating to find these artifacts especially if you forget to take corresponding flats. It's happened to me more times than I can remember or willing to admit.
The "splotch" may not necessarily be on your sensor but if it is you can try using this kit to clean it off. CMOS sensor cleaning kit
Good luck, I hope you get all those pesky dust motes out of your optical train.
Here is the photo so far with DBE and Spectrophotometric Color Calibration done on it. This is definitely more than I ever extracted from Photoshop.
Edit: I realize I only did a STF, I still need to get it so that the image itself is stretch. I'll reupload it once I get it done.
Here is the final processed image that I did in PixInsight.
I followed Gary T's tutorial, and that really helped a lot!
Well done, I like how you handled the brightness of Alnitak, that can be challenging and often overwhelms the image but not in your case. Your image has good contrast and does a great job displaying the variation of colors in that area. I know you took a lot of subs -- if you have time, I think the image can benefit from the addition of even more subs, to cut through all that light pollution but that's entirely up to you. There are a few minor details that can still be can be addressed or you can leave it the way it is. Over all, it's impressive how much data you were able to extract from those faint subs you showed us in the beginning. Keep it up, this just keeps getting more fun as you go along.