Search found 800 matches

by oopfan
Thu Nov 19, 2020 2:29 pm
Forum: Gallery
Topic: Perseus Double Cluster
Replies: 6
Views: 312

Re: Perseus Double Cluster

Thanks, Bruce, but you know, it never fails, every step forward leads to more head scratching and then refinement. We, I mean "I", never seem to be happy with what I've accomplished. I thank you for your kind words!

Brian
by oopfan
Thu Nov 19, 2020 1:20 pm
Forum: Gallery
Topic: Perseus Double Cluster
Replies: 6
Views: 312

Re: Persius Double Cluster

Thanks, Dave. Something I noticed: The diffraction pattern depends on the filter as can be seen in the attachment. I am certain that this is due to the 2mm thickness of the Newtonian Mask's vanes. Long wavelengths (red) diffract more than short wavelengths (green), so red light does a better job of ...
by oopfan
Thu Nov 19, 2020 5:24 am
Forum: Gallery
Topic: Perseus Double Cluster
Replies: 6
Views: 312

Perseus Double Cluster

aka NGC 869 + NGC 884 William Optics ZenithStar 71 Achromat Atik 314E Mono CCD GSO Wratten #12 Optolong Red and Green W12: 26x60s R: 70x60s G: 35x60s Color Combine: W12 => L 67% R => R 33% R + 33% G => G 67% G => B Post-process color calibration not needed due to balanced frame count (planned ahead ...
by oopfan
Tue Nov 17, 2020 2:34 am
Forum: Gallery
Topic: Open Star Cluster M34: Colorful Stars without a Blue Filter
Replies: 3
Views: 222

Re: Open Star Cluster M34: Colorful Stars without a Blue Filter

Hi Bruce, I very much appreciate your feedback. Very insightful. Today, I added the W12 frames that I captured last week with the color frames from the other night. According to my calculations it raised the total signal-to-noise ratio from 60 to 87. There is something interesting happening that I t...
by oopfan
Sun Nov 15, 2020 2:29 pm
Forum: Gallery
Topic: Open Star Cluster M34: Colorful Stars without a Blue Filter
Replies: 3
Views: 222

Open Star Cluster M34: Colorful Stars without a Blue Filter

No doubt, you will read this and ask yourself: Why? To answer that question, I must explain that I have an Achromat refractor, not an APO. The William Optics ZenithStar 71 was marketed as "APO-like", and the price point was good! Well, I discovered only later that a lot of people are unhap...
by oopfan
Thu Nov 12, 2020 8:43 pm
Forum: Other Astro Imaging
Topic: Luminance filter vs Wratten #12
Replies: 8
Views: 1755

Re: Luminance filter vs Wratten #12

Exactly my thoughts!
by oopfan
Thu Nov 12, 2020 4:12 pm
Forum: Other Astro Imaging
Topic: Luminance filter vs Wratten #12
Replies: 8
Views: 1755

Re: Luminance filter vs Wratten #12

Robin,

This filter would probably be helpful, but I would have to 3D-print a custom holder to fit my filter wheel.

Brian
Edmund Blue Bandpass 475CW 50FWHM .jpg
Edmund Blue Bandpass 475CW 50FWHM .jpg (82.43 KiB) Viewed 1698 times
by oopfan
Wed Nov 11, 2020 10:02 pm
Forum: Other Astro Imaging
Topic: Luminance filter vs Wratten #12
Replies: 8
Views: 1755

Re: Luminance filter vs Wratten #12

Hi Robin,

I will look into a narrow blue filter, but the downside is the increased integration time needed for the blue stack.

Thanks for your help,
Brian
by oopfan
Wed Nov 11, 2020 12:48 pm
Forum: Other Astro Imaging
Topic: Luminance filter vs Wratten #12
Replies: 8
Views: 1755

Re: Luminance filter vs Wratten #12

Hi Robin, Next opportunity, I will image M34 again, and capture a stack of W12, R, G, and B. First, I'll use APP to try to create a color image using W12 as L. Hopefully that will give acceptable results. Second, I'll borrow a technique from narrowband to create a bi-color image from two channels: 1...
by oopfan
Tue Nov 10, 2020 8:50 pm
Forum: Gallery
Topic: Open Star Cluster NGC 1664 using a Newtonian Mask
Replies: 4
Views: 550

Re: Open Star Cluster NGC 1664 using a Newtonian Mask

Thanks for reminding me of NEAT, Dave.

Here is the same image of NGC 1664 as posted earlier, but now employing NEAT for noise reduction:

Brian
NGC-1664_W12-50x85s_APP-CON0-G95-S15-3-25_filtered.jpg
NGC-1664_W12-50x85s_APP-CON0-G95-S15-3-25_filtered.jpg (389.5 KiB) Viewed 528 times