NGC7822 in Ha, OIII, NII and SII

[Bob Andersson]

Hi folks,

 

 

          NGC7822

 

And here it is at 2048 x 2048.

 

TEC 140 plus FLI ML16803 mounted on a DDM60 Pro.

Ha - 8 x 1500secs, OIII, NII and SII all 18 x 1500 secs, R, G and B each 8 x 200 secs.

Astrodon 3nm filters used for the narrowband subs. Processed in PI and PS.

 

The colour palette is ordered by atomic weight with Ha = red, OIII = orange, NII = green with a splash of blue and SII = blue. White balance of the nebulosity was set in those areas where Ha, NII and SII reached their maximal values.

 

The palette chosen may be unusual but I think it has virtue, both aesthetically and as an aid to seeing what is going on. It also means that there is a chromostereopsis effect with the whiter and bluer stars and, to some extent, the whiter nebulosity appearing to float slightly in front of the redder parts of the image. Such a 3D effect is pure fiction of course, but fun if you like to let your imagination lose. If you don't see this effect then you may need to relax your eyes slightly as you view the image. If you still don't see it then maybe you just have really good eyesight.   Best seen on the larger image and, if possible, with a dark surround.

 

The DDM60 Pro performed beautifully. At just under 2 seconds of arc per pixel the stars in the Ha subs were nice and round even thought the mount was unguided.

 

Bob.

Edited September 1, 2013 by Bob Andersson

[RamaSpaceShip]

Wahoooo!!!  The 3D effect is very impressive. Very, very nice image. Please do more

 

Regards.

 

Bernard

[mattssporre]

Lovely image Bob!

 

NII is a nice addition to the usual Ha, OIII, SII. Was the signal strong in NII?

 

I guess you are using 3nm filters?

 

BR
Matts

[Bob Andersson]

Hi Matts,

 

NII was stronger than SII and OIII was quite weak. Yes, I am using 3nm filters (Astrodon). Even so I subtracted a small fraction of the much stronger Ha signal from the NII. Not enough to get anywhere near black clipping but enough to improve the contrast of the NII image a little without introducing unwanted Ha detail.

 

Bob.

[afesan]

I like the 3D sensation a lot. Congratulations for this nice result. Also colours are very different compared with the "traditional" Hubble or CFHT palettes..

 Nice , nice job ¡

 

BR

Antonio

Edited September 13, 2013 by afesan