ngc 6946

[alacant]

Hi everyone

Steady seeing meant we could use the big reflector, but Sod would have that it be accompanied by a 90% moon. Processing was a bit of a mess; there seems to be a lot of background light/dust for which we can't account so what looks like noise -we'd like to think!- isn't.

Another challenge was to be the first post ever not to mention either fireworks or supernova. Ah well, maybe next time...

Thanks for looking. We're always trying to improve so any comments -e.g. the colour- most gratefully received.

700d on 250p ~2h

 

[ollypenrice]

Nice, but for constructive criticism I think nudging the target up a bit in the frame would be logical.

For me the galaxy is a little bit on the green side. This is an odd target whose colour hangs very critically in the balance on the green-magenta axis so renditions do vary.

Also, you have have a grid pattern thing going on in the background. It's perhaps easier to see when partially equalized in Ps. Is this the famous 'Canon banding?' I don't know what camera you used.

Olly

 

[alacant]

 

Yeah. Stretch a jpg and that's what you get.

Unfortunately, we don't have calibration frames. Trying to control it all having been invited to a rowdy Friday night out in Benidorm doesn't exactly induce good ap practice...

Good point about the nudge. I think it's worth starting this one over, end of next week. This time sitting next to the telescope;)

[ollypenrice]

I doubt that's a JPEG artefact. I've seen the same thing in FITS files from a QSI683 we were trying. (That was after flats, darks and stacking, too.)

Certainly worth another look. I have the galaxy but not the cluster so I might mosaic it.

Olly

 

[RichLD]

6 minutes ago, ollypenrice said:

I doubt that's a JPEG artefact. I've seen the same thing in FITS files from a QSI683 we were trying. (That was after flats, darks and stacking, too.)

Certainly worth another look. I have the galaxy but not the cluster so I might mosaic it.

Olly

 

 

Nice shot but I agree it's a little on the green side.

I've seen this artefact generated by different brands of camera that use the KAF8300 - you mentioning the QSI683 adds to the theory. I wonder?

[ollypenrice]

32 minutes ago, RichLD said:

 

Nice shot but I agree it's a little on the green side.

I've seen this artefact generated by different brands of camera that use the KAF8300 - you mentioning the QSI683 adds to the theory. I wonder?

I'm following this up with a friend who, from memory, had a firmware fix in his case.

Olly

[alacant]

Hi everyone and thanks so much for your time and input.

I think the background is rubbish because we didn't take flat frames.

The camera is a humble bashed around canon. I got some offset frames sent over which I think have helped a little. Had a go with StarTools' colour, but still not sure. There are as many colour schemes as there are image search examples. Take your pick.

We're calling this one the benidorm palate. Maybe it'll catch on:

 

 

[ollypenrice]

Nope, flats won't fix your chequerboard background, nor will darks or bias. Hey, I might be totally wrong but I'd put a good old fashioned 'fivah' on it, by Gad! Flats would fix the bright bulge above the cluster, certainly. No free tapas in this game!

lly