Search found 11 matches

by RickEvans10473
Sat Oct 03, 2020 1:55 pm
Forum: Gallery
Topic: M31 Andromeda core globular clusters map
Replies: 6
Views: 528

Re: M31 Andromeda core globular clusters map

Wow. Very impressive. I will be looking at my own M31 core image to see how many globulars I might have picked up.
by RickEvans10473
Sun Aug 26, 2018 10:00 pm
Forum: Deep Sky Imaging
Topic: Artifacts with dark frame subtraction
Replies: 20
Views: 5241

Re: Artifacts with dark frame subtraction

Hi Robin, As promised I tested dark frame subtraction using the Raw16 color space and there were no artifacts. I have not had a chance to play with the live flat frame subtraction but did use SharpCap to generate. I have a few questions about version 3.2. I see it's beta and expires on September 30....
by RickEvans10473
Thu Aug 23, 2018 1:47 pm
Forum: Deep Sky Imaging
Topic: Artifacts with dark frame subtraction
Replies: 20
Views: 5241

Update Re: Artifacts with dark frame subtraction

Hi Robin, For the first time since since last posting I got a clear, albeit moon lit, night here in the US Mid Atlantic States. I was able to test the dark frame subtraction on M13 and M27 in RGB24 mode using Version 3.2 The good news is there were no artifacts when using Version 3.2 .To be sure I u...
by RickEvans10473
Thu Aug 16, 2018 3:33 pm
Forum: Deep Sky Imaging
Topic: Artifacts with dark frame subtraction
Replies: 20
Views: 5241

Re: Artifacts with dark frame subtraction

"Hi, please retest with 3.2.5696 when you have a chance - I have made significant changes to the dark subtraction code that I think will reduce or eliminate this type of artifact. There are a lot of different cases to cover in the dark subtraction, so I hope I (a) found them all and (b) changed...
by RickEvans10473
Wed Aug 15, 2018 1:57 pm
Forum: Deep Sky Imaging
Topic: Artifacts with dark frame subtraction
Replies: 20
Views: 5241

Re: Artifacts with dark frame subtraction

Hi Brian, "It appears that the artifacts are only happening on the brightest stars. Perhaps the camera's pixel scale and the telescope's focal length have led to severe undersampling. SC could be misinterpreting stars as hot pixels. The pixel size is 4.63 um so if the telescope is relatively sh...
by RickEvans10473
Wed Aug 15, 2018 3:10 am
Forum: Deep Sky Imaging
Topic: Artifacts with dark frame subtraction
Replies: 20
Views: 5241

Re: Artifacts with dark frame subtraction

Un-subtracted light frame
M092_00001.png
M092_00001.png (519.13 KiB) Viewed 2355 times
by RickEvans10473
Wed Aug 15, 2018 3:07 am
Forum: Deep Sky Imaging
Topic: Artifacts with dark frame subtraction
Replies: 20
Views: 5241

Re: Artifacts with dark frame subtraction

Hi Robin

You asked: "do you have a copy of the dark frame that you were using and an unsubtracted light frame that you can share?"

Dark Frame
dark_10_frames_0.0C_2018-08-09T00_23_04_5555.png
dark_10_frames_0.0C_2018-08-09T00_23_04_5555.png (867.83 KiB) Viewed 2355 times
by RickEvans10473
Mon Aug 13, 2018 3:00 pm
Forum: Deep Sky Imaging
Topic: Artifacts with dark frame subtraction
Replies: 20
Views: 5241

Re: Artifacts with dark frame subtraction

"Yes I see the artifacts. I am sure that Robin will solve." Certainly, hope so. The only reasons for me "upgrading" to the paid license of 3.1 is 2.9 would not recognize my ASI294MC Pro and I liked the convenience of real time dark frame subtraction. I hope the flat frame subtrac...
by RickEvans10473
Mon Aug 13, 2018 1:45 am
Forum: Deep Sky Imaging
Topic: Artifacts with dark frame subtraction
Replies: 20
Views: 5241

Re: Artifacts with dark frame subtraction

M22 Image deleted in last post
M22_cropped_23_04_g3_ap154.jpg
M22_cropped_23_04_g3_ap154.jpg (384.08 KiB) Viewed 2417 times
by RickEvans10473
Mon Aug 13, 2018 1:42 am
Forum: Deep Sky Imaging
Topic: Artifacts with dark frame subtraction
Replies: 20
Views: 5241

Re: Artifacts with dark frame subtraction

Brian, Unfortunately, I don't have an Autostakkert image for the image in the original posting. Actually there should have been two images in the original but for some reason the second image was not posted. Below is an image of M15 stacked images dark frame subtracted by SharpCap 3.1. For the M22 i...