My pics turns brownish, why? Please help

[HenryW]

Normaly my pics turns to the bluish before, during and afer prosessing, but on a sudden my pics are moving to the brownish side , why does this happen? No camera settings have been altered since last pics that turned bluish.

SW 130PDS

Canon 550D

80x60s subs

25 darks

30bias

[Knight of Clear Skies]

Chocolate on lens?

Nice image but to my eye it's a little yellow (red + green), so you could try increasing the blue channel. You also have quite a black sky so you could try increasing the brightness to bring out the fainter details. The night sky isn't really black, it's a light grey.

[Knight of Clear Skies]

As to why you're getting different colour in different sessions, I can think of a few possible reasons. Objects in the sky appear redder the closer they are to the horizon, because the atmosphere scatters blue light more readily and you are looking through more of it. Seeing conditions and moisture content in the air may also play a role. Finally, if your camera is unmodded it will block a significant amount of Ha light, but this will only be apparent on some targets.

I don't know a lot about DSO imaging, but I think it is normal practise to equalise the colours in the histogram by aligning the peaks for each colour channel. Hopefully a more experienced DSO imager can confirm this.

Hope that is some help.

[HenryW]

Thanks for input :-) The ytrange thing is that, in my opinion, the pics taken earlier this year looks better even though the exposure time is much shorter

25x 30 sek lights...
30x 30 sek darks
30 bias

 

[carastro]

Were you using a CLS filter with the blue ones and not with the brown ones by any chance?

CLS filter makes images blue and LP makes images brown.

Carole 

[HenryW]

No filter was used, but you gave me somehing to think about. The night is becoming shorter and shorter up here in the north giving me shorter and shorter imaging time.

Thanks!

[Knight of Clear Skies]

Thanks for input :-) The ytrange thing is that, in my opinion, the pics taken earlier this year looks better even though the exposure time is much shorter

You're welcome. Looking at the two closely, I think I can see a little more detail in the arms of M81 in the longer exposure. There probably is more data in there, but you might need to stretch that part of the histogram in order to make it out fully.

[HenryW]

Better than nothing

[Knight of Clear Skies]

That's looking really good. That fuzzy patch above and right of the core is a satellite dwarf galaxy, I forget its name now.

[HenryW]

Thanks! I thought the fuzzy patch you mention was some artifacts on my lenses, good find :-)