Markarian's Chain in Virgo

ZWO 1600mm cooled camera (But cooling was NOT turned on.
StellarVue SV70T Scope.
Captured as 30 second subs in SharpCap Pro - (8bit FITS) I know, should have been set to 16bit.
I captured 60 subs, 30 darks and 30 lights and ran it through the default settings in DSS
Opened it in Photoshop and adjusted levels and curves and discovered the horrible black bar across the top.

Any ideas about the black bar? It does not show up in the individual subs.

IMAGE LINK: https://photos.smugmug​.com …i-Tt8ZvQf-X2.png&lb=1&s=A

Nice set of galaxies. It’s incredibly blue how many there are when you look at the annotated version. Did you do a crop after alignment and stacking?

rdricks wrote in post #19049405
Did you do a crop after alignment and stacking?

No, other than what was cropped in the DSS stacking process.

I love that target...targets... I't one I image over and over. It is so amazing to see that many galaxies packed into a FOV that is perfect for us amateurs. As for the bar, try a few things with DSS and see if you can eliminate it. Stack without the DARKS, or only stack 1/2 of the LIGHTS. See if the bar goes away. I know I used to get odd things with BIAS/OFFSET frames. I've never seen a bar like that caused fron DSS other that framing being off after the meridian flip.

I’m not familiar with DSS, it looks a little like framing is off as TC mentioned. I usually use APP or PixInsight, and crop quite a bit off edges. Give some of his other suggestions a go.

The black bar mystery has not been completely solved but I have finally had a chance to look at the individual frames and with some serious stretching I see the black bar in the individual frames too. Just looking at the frames without stretching the bar doesn't show up.
So I still can't figure out what caused the black bar, hoping it's not my camera sensor going bad, but at least I now know it's not an artifact from the processing in DSS.

hey, was live view on or off? I remember the mirror flipping up causing a bar like that. I always left the mirror flipped up as I shot. Just a thought.

Toxic Coolaid wrote in post #19050324
hey, was live view on or off? I remember the mirror flipping up causing a bar like that. I always left the mirror flipped up as I shot. Just a thought.

This was shot with a dedicated astro cmos camera. No physical shutter on the ZWO 1600MM.

oops....forgot to back to the top and read. That was only on the 1st line