Getting the Toes of the Histograms to Begin at the Same Place

[dgbarar]

Hi NGC,

Green should be the "stronger" channel as it is the one that contains Ha.  The green channel was composed 15% Ha and 85% OIII.  But you do make an interesting point and have given me a thought. I am going to go back and try this again with channels that do not have mixed components and see how it works out.

Cheers,

Don Barar

[Phil Leigh]

The Linear Fit method works fine on a normal RGB image taken through a Bayer Matrix or through RGB filters. In your example histogram the three channels do indeed start from the same "black" point.  As far as the shape/slope of the Histogram curve is concerned - For a false colour narrowband or hybrid image the "RGB" channels have no natural relationship to each other that is baselined in reality anyway so deciding the shape of the histogram curves is an aesthetic decision.

[dgbarar]

Hi Phil,

Thanks for taking time to review my examples.  I agree with much of what you said.  However, I do not see in any of my posted examples where all three channels have the same "black point".  Why do you feel this way?

Cheers,

Don Barar