M35 and NGC 2168

[astrorabbit]

Comments and tips welcome, this was under full moon and heavy light pollution.

Can anyone explain the purple/green background??

Cheers.

M35 and NGC 2168, 40 mins stacked, ISO 1000 by matthewpierzchala, on Flickr

[astrorabbit]

That's meant to be NGC 2158... Woops!

[Daniel-K]

Nice one you should do m38 that has a small ngc next to it aa well. The green could be from a filter if you're using one if not its juat a bad gradient caused by the moon. A simple plug in for photoshop called HLVG will sort that out. Its free software and works great

[sologuitarist61]

Very nice image!

[Pete Presland]

Nice image, this was one of first DSO's i took. Nice open cluster and a bonus!

Sent from my GT-I9100 using Tapatalk 2

[astrorabbit]

Thanks for the kind words chaps. I think the gradient may be due tk bad flats in my stacking too. I need to figure out a way not to over expose the flats and retain actual information regarding dust and vignetting.

Does anyone know if the flats would be processed in DSS even if their exposure times are different?

[cfpendock]

Thanks for the kind words chaps. I think the gradient may be due tk bad flats in my stacking too. I need to figure out a way not to over expose the flats and retain actual information regarding dust and vignetting.

Does anyone know if the flats would be processed in DSS even if their exposure times are different?

The exposure time for flats will almost certainly be different, and yes you can process them in DSS.  Just load them as "flats" and the stacking process takes care of the rest.  I may be wrong, but I think that your image is suffering from severe vignetting more than plain gradient.  The flats should take care of the vignetting so long as you do not rotate the camera with respect to the lens, and also so long as you don't change the focus.

Once you have got rid of the vignetting effect, you can lower the black point (not too much), which will almost certainly help with the greenish tinge.

Chris

[astrorabbit]

I'm sure I saw somewhere that the flats need to be the same settings as the lights, it didn't make sense!

Well that will definitely help the vignetting, and thanks for the tip on the black levels, I will try that on my next target!

I think with the lessons learnt I will try imaging the glorious m42 again but through my Oiii filter

[Daniel-K]

try aligning your RGB channels or reducing the green channel to get rid of the green.

[Skyline]

Im sure you can pull out some more data from that image, you can use some tools like Noels Actions for getting rid of Gradients.