This particular camera came with a front adapter that is not quite large enough ID to fully illuminate the corners. I did not bother to take a flat, but it is definitely needed. There is approximately 5% light fall-off in the very corners due to this restriction. That's not a huge amount and can be handled by a flat frame. (see image below)

Rolando

-----Original Message-----
From: AaronW <aaron.wilhelm@...>
To: main@ap-ug.groups.io
Cc: main@ap-gto.groups.io
Sent: Fri, Jun 25, 2021 1:14 pm
Subject: Re: [ap-ug] M5 - the lonesome Globular

Beautiful!

I am also quite interested in the 6200 and how it works with refractors in the 130mm range.  I have a William Optics Fluorostar 132mm refractor that is advertised as fully illuminating a full frame sensor (such as the 6200), but I have heard several reports of terrible corner stars and severe vignetting (the kind that flats cannot fix) when paired with this particular scope from WO.  Did you have any trouble fully illuminating the full frame of the 6200?

Best,

Aaron

On Jun 25, 2021, at 8:39 PM, Roland Christen via groups.io <chris1011=aol.com@groups.io> wrote:



Hi Astronuts,

While trying out the new ZWO 6200 MC Pro color camera that George graciously lent me, I was rummaging around the early evening sky trying to find something bright and colorful to image. There really isn't much available between the rich galaxy swarms of Spring and the later Milky Way treasures of Summer. I spotted this Glob sitting all by itself in what seems like empty space, at least so it seems from my light polluted site.

The real reason for shooting with this camera was to check out the spacing requirements of our Quad TCC and the 130 GTX refractor. I was also interested to see what kind of resolution to expect using the tiny 3.75 micron pixel CMOS chip with a mere 655mm focal length and 130mm aperture. So, without further ado, here she be:

https://www.astrobin.com/jfm6hf/

The image had to be cropped from the full size in order to upload it to Astrobin. Full size color image is an insane amount of mega-pookles.

Rolando

--
Roland Christen
Astro-Physics

Hi Mike,

I use MaximDL for most of my processing. Since the center of the cluster is so bright compared to the rest of the image, i use Digital Development filters to suppress the center while bringing out the outer parts. Then in Photoshop I select this center part with heavy feathering and layer it on top of the normal stretched image. This works well for some galaxies too where the core is so bright that it saturates before the outer parts show up.

Rolando

-----Original Message-----
From: M Hambrick <mhambrick563@...>
To: main@ap-gto.groups.io
Sent: Sat, Jun 26, 2021 8:17 am
Subject: Re: [ap-gto] [ap-ug] M5 - the lonesome Globular

Great image Roland

What is your processing method for images of globular clusters to bring out the detail in the center ?

Mike

--
Roland Christen
Astro-Physics