The Horsehead: with a problem

[Daveskywill (David)]

Hi:

I've obtained better horsehead nebula pictures using my Celestron RASA and

Nikon D800 instead of the Meade LX200GPS 10"F10 mount, scope and 80mm.

Since the building of that older observatory, I've moved to Plymouth, Indiana,

just 8 miles sw of Bremen where now my parents have bought a nice duplex

home and soon after I get out of this rehabilitation group home, Shady Rest

I'll someday be out and ready to re-build my observatory on my sister Lisa's

and Kenny's (her husband's) place.

But this one artifact on (After I think about it, it's on all my astrophoto's)

Is of a purple equalateral triangular halo. And it seems to move the opposite

direction of the stars when I slew. And you see in this one wide-angle

shot of the Horsehead, there are even 2 and I don't know why there isn't

even a 3rd one. But could someone please diagnose this problem?

What should I do to fix it?

Thanks

David

[spiezzy]

hi David could it be bad flats calibration looks like one of mine I did a while back and the flat frames didnt calibrate properly the image it self looks ok .
cheers Pete

[glend (Glen)]

I would suggest you have a light leak somewhere in the imaging train. Have you shot any darks with that same configuration?

[doppler (Rick)]

Another possibility: Light leaks via the viewfinder. Being essentially a small optical path that receives light bounced off the prism and mirror inside the camera, it often does the reverse of its job too. Light enters through the viewfinder and bounces off the prism and mirror and then goes onto the sensor. Google "nikon d800 light leak"

[rally]

Are you referring to the large purple expanse either side of the horse ?
Thats IC434 an emission nebula.

The purple colouration is the DSLR/Processing response to Hydrogen Alpha emissions

[rcheshire (Rowland)]

Can you mark the artefacts or are you referring to the abberations in the attached image?

[rustigsmed (Russell)]

aberrations shown by Rowland looks like chromatic abberations, maybe caused by capturing low to the horizon or perhaps a misalignment of lenses in the imaging train (not square).

the white hazy part looks like bad flats - or not using any flats at all - it could be a light leak but i suspect it isn't as usually they are more irregular - to be sure turn it off live view before capture.

attached i did a bit of artificial flat creation and then subtraction.

[phomer (Paul)]

David,

It would be more assistance to give us some details on what processing you have performed.

You have a number of issues but I cannot determine where the purple equilateral triangle is.

Regards

Paul

[rally]

How about a reply from the OP ?
5 days later with 7 replies and nothing !