Eastern Veil NGC6992 and NGC6995

W7AY · Post by **W7AY** » Sat Aug 10, 2019 5:39 pm

Borg 71FL at f/4
ASI183MC Pro
Radian Ultra Quad Band filter
42 x 180s Gain 111 at -10ºC, 79 Darks, no flats
RainbowAstro RST-135 autoguided with ASIAIR
AstroPixelProcessor (MacOS) with color touchup with Affinity Photo.

wvreeven · Post by **wvreeven** » Tue Aug 20, 2019 12:07 pm

Very nice image! It does seem, however, that there is some vignetting in the image. Did you apply flats?

Wouter

W7AY · Post by **W7AY** » Fri Aug 30, 2019 7:08 am

Good eyes :-). As I mentioned in the original post, "Dark, no flats." This was a quick test of the Radian filter over a couple of nights at my Bortle 5/Bortle 6 home.

The Borg 71FL has lots of dropoff towards the edges when using the 0.72x reducer/flattener (f/4). It is much better with the 1.08x flattener (i.e., at f/6).

I have since tested the RedCat (white version) and will probably be using the latter for wide fields, while relegating the Borg 71FL to narrower fields.

Chen

wvreeven · Post by **wvreeven** » Mon Sep 16, 2019 12:31 pm

Sorry, failed to notice that. Still, great image!