Another histogram question :)

[Aza]

Hi

I am just taking Ha subs with my DSLR.

When I open one of the subs, the histogram has 3 peaks at the black end, rather than the usual 1.

What does this mean? And when I adjust the black point do I need to keep all 3 peaks, or just the 'main' one?

Thanks

[blinky]

I would assume the 3 peaks correspond to red, green and blue. I would ignore all but the red since it is Ha you are imaging.

[Aza]

Ah that makes sense. I was just viewing the red channel, but I guess I was viewing the complete histogram.

Thanks for that