Search found 828 matches

by oopfan
Wed Feb 17, 2021 11:29 pm
Forum: Gallery
Topic: M47 (Open star cluster) & M42 (Final revision)
Replies: 13
Views: 332

Re: M47 (Open star cluster) & M42 (Final revision)

Rick, Star quality improves as we move on to cameras having a greater Full Well Depth (FWD). Your camera, using gain 115, has a FWD of only 4,000 electrons. My camera has only one gain setting, so FWD is fixed at 13,400 electrons. If you were to choose your lowest gain, then FWD would be 15,000 elec...
by oopfan
Wed Feb 17, 2021 4:04 pm
Forum: General Discussions
Topic: NGC7635+M52, re-processed with 2 year gap
Replies: 3
Views: 139

Re: NGC7635+M52, re-processed with 2 year gap

Thanks, Dave. Your statement rang a bell: The Subtractive Chromatic Noise Reduction (SCNR) technique is used to deal with green noisy pixels (a by-product of having 2 green pixels for every blue and red pixel in the camera sensor matrix). This is a 'one click' operation in Siril. I have virtually no...
by oopfan
Wed Feb 17, 2021 5:29 am
Forum: Gallery
Topic: M47 (Open star cluster) & M42 (Final revision)
Replies: 13
Views: 332

Re: M47 (Open star cluster) & M42 (Final revision)

Hi Rick, I haven't imaged M47 but I can show you my Perseus Double Cluster from a couple months ago: Perseus-Double-Cluster_W12-26x60s_R-70x60s_G-35x60s_APP_S15-3-25_SA-35-25_G94_SC_AFF_Denoise-2.jpg I was rushing to finish it before it passed behind trees so I had poor focus in two of the three fil...
by oopfan
Tue Feb 16, 2021 3:29 pm
Forum: Gallery
Topic: M47 (Open star cluster) & M42 (Final revision)
Replies: 13
Views: 332

Re: M47 (Open star cluster) & M42 (Final revision)

Hi Rick, I searched for images on AstroBin that used the ASI183MC. I found this: https://www.astrobin.com/409604/0/ He used SharpCap 3.2 and I assume LiveStack since he didn't mention any other software. He's got a Celestron C8 SCT like you. He doesn't have HyperStar, but he is using a 0.4x focal re...
by oopfan
Tue Feb 16, 2021 2:20 pm
Forum: Gallery
Topic: M47 (Open star cluster) & M42 (Final revision)
Replies: 13
Views: 332

Re: M47 (Open star cluster) & M42 (Final revision)

Hi Rick, I created a side-by-side comparison of your original image and the reworked one. I zoomed in: Rick M47 before and after 1.png I annotated the image to show, what I believe to be, artifacts of aggressive denoising. Can you have another go at it? But this time: 1. No denoising. 2. Show outer ...
by oopfan
Sun Feb 14, 2021 9:53 pm
Forum: General Discussions
Topic: ASI2600MC To take Darks / Dark Flats or Not
Replies: 14
Views: 174

Re: ASI2600MC To take Darks / Dark Flats or Not

Take a look at this:
https://rumble.com/vcqant-brians-late-n ... d-flu.html

300s and 600s stacks from data I purchased. Notice that the exposures aren't 264 seconds and 553 seconds.
by oopfan
Sun Feb 14, 2021 9:47 pm
Forum: General Discussions
Topic: ASI2600MC To take Darks / Dark Flats or Not
Replies: 14
Views: 174

Re: ASI2600MC To take Darks / Dark Flats or Not

Nick,

I'm just telling you what pros do. If you want to go down the path you are on, don't let me stop you. You are just making more work for yourself.

Brian
by oopfan
Sun Feb 14, 2021 8:57 pm
Forum: General Discussions
Topic: ASI2600MC To take Darks / Dark Flats or Not
Replies: 14
Views: 174

Re: ASI2600MC To take Darks / Dark Flats or Not

Nick, You can use one exposure for all objects, or you can sort objects into two classes: medium-to-bright and faint-to-medium. The objective is to choose an exposure that ensures a decent signal-to-noise ratio per frame. The reality is that if your SNR is too low (say less than 1.0) then you are co...
by oopfan
Sun Feb 14, 2021 8:00 pm
Forum: Gallery
Topic: M51 plus and minus HA
Replies: 3
Views: 130

Re: M51 plus and minus HA

Hi Tim, Excellent work! Another thing to consider regarding the bandwidth of an Ha filter, there are two Nitrogen lines on either side of Ha. A 3nm filter will nicely isolate Ha, but a 6nm filter will pass some NII. Not all emission nebulae have strong NII, but enough to make life interesting. I've ...
by oopfan
Sun Feb 14, 2021 7:41 pm
Forum: Gallery
Topic: Color Correction in a non-APO refractor
Replies: 7
Views: 204

Re: Color Correction in a non-APO refractor

Hi Tim,

I like your Beehive very much! And I agree that it looks like the colors fall somewhere between my two images. When and if I ever get another clear night I will try a non-stellar object like M51. I am very curious to see the range of colors.

Thanks,
Brian