A comedy of errors (NGC 6992)

[peonic]

Whole raft of issues conspired against me (the worst of which being I fell alseep on the sofa whilst cuddling the cat and didn't notice a PHD failure that meant I wasn't guiding for well over 2½ hours!).

Also managed to fail to re-acquire the target after a meridian flip (missed a setting in NINA, it was my first time using it!)

Finally managed to lose guiding completely due to lack of a dew tape for my guidescope, so gave up at 2:30am.

 

So what I was hoping was going to be 3 to 4 hours of data turned into 65 minutes - but it still shows improvement on my previous attempts so I'm going to post it and ask for more pointers!

 

13x300s

ZWO ASI533MC Pro

Optolong L-Enhance

ED80/HEQ5

 

Captured with NINA, rough process in PI and Photoshop.

Comments, critique and tips hugely appreciated!

 

Chris

Edited August 28, 2022 by peonic

[iantaylor2uk]

Nice image - as it happens I also took a photo of this target last night. I used a Tak TSA 102 f/8 refractor (focal length 816 mm) with 1x flattener and L-Enhance filter, on RST-135 mount, a ZWO 071 MC Pro camera (with gain = 200 and 180 sec exposures, cooled to 0 C). 

I got about 2.5 hours of images. Inititally processed result (using DSS and Nebulosity 4) is shown below. I tend to push the gain up when using the L-Enhance filter. 

 

[peonic]

The quality really shows there Ian!

 

Out of interest, what do you push the gain to when using the Optolong filter? I tend to keep my 533 at unity unless i'm framing or focusing.

 

Chris

[peter shah]

Super result despite your challenges....besides its no fun if you are not fighting with the kit!!

[iantaylor2uk]

Thanks Chris - I've found that the higher gain is OK for the 071 camera (max gain is 240, and I am using 200), and since I am using a slow refractor (f/8) it saves imaging for longer. My single subs were only 180 seconds, and I got a reasonable result with only 2.5 hours of imaging. I know that the dynamic range is worse at higher gain but on the other hand the noise is a lot lower + you get some of the dynamic range back when stacking multiple subs. You could always try some sessions at higher gain with the 533 camera and see if is OK. 

My exposure times are usually three times longer when using the L-Enhance filter. If I am just using a UV/IR filter I would typically only take subs between 30 and 60 seconds (although in this case I may drop the gain down to 90 - which is unity for this camera and go a bit longer, maybe up to 120 secs). 

Incidentally, if you want to look in more detail at the photo, the full frame bitmap of my image can be accessed at:

 https://drive.google.com/file/d/1BrdOp55rXIeYO58z-3b89dCf1hgLgT0q/view?usp=sharing