Purple flare: Causes and remedies

Started Mar 1, 2013 | Discussions thread
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Cani Regular Member • Posts: 386
Re: Hmmm... CC experiment implies non-linear process...

kenw wrote:

The bigger question to me is the CC filter result. It implies a non-linear (i.e. violating superposition) process is occurring. Such things are exceedingly rare in optics as superposition is a basic tenant of E&M theory. Immediately attention is drawn to the sensor itself or the post processing (recovering WB and exposure compensation) as the only likely sources of a non-linearity. Do you have a theory for what is going on with the CC filter experiment?

It is not clear to me why you think the result implies non-linearity. Could you elaborate on this?

I kind of "see" (on my potentially ill-calibrated screen) that the highlights have lost part of their purplish cast in the original picture, and that the second version with a modified WB  has completely lost it's purple flare.

Do you mean that for both versions of the second picture the results seem to violate superposition, but cannot and thus it's an artefact from an origin that remains to be determined? Or do you believe superposition can be violated?

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