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  Previous versions of Bifurcator's message #9629044 « Filters cutting down Purple Fringe CA? »

  

Bifurcator
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Re: Filters cutting down Purple Fringe CA?


Well, since PF chromatic aberration is worst for the shortest wavelengths that a sensor is sensitive to (violet and/or ultra-violet light) I would expect a UV cut filter to help somewhat, yes. Additionally since a polarizer decreases the amount of \"stray\" light rays which contributes to bloom and haloing, I would expect it to help as well. The reason it\'s considered mostly to be a digital phenomenon is because most films are not nearly as sensitive to the V and UV portion of the spectrum (which is where PF is from) as digital sensors are. I also hear it\'s much worse on CCD sensors than N-MOS or C-MOS ones.

But true PF can all be removed in Adobe\'s Camera Raw or many other processors. Here\'s some links about PF and the removal thereof - either with filters or with software:

http://www.great-landscape-photography.com/ultraviolet-filter.html
http://www.great-landscape-photography.com/remove-purple-fringing.html
http://www.pcworld.idg.com.au/article/75955/removing_purple_fringing/
etc.

I guess how much a UV filter will help will depend on the camera\'s own internal filter blocks and the sensor\'s sensitivity to UV. And how much a polarizer will help will depend on how susceptible the lens in question is to flare and ghosting.





May 29, 2011 at 09:31 AM
Bifurcator
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Re: Filters cutting down Purple Fringe CA?


Well, since PF chromatic aberration is worst for the shortest wavelengths that a sensor is sensitive to (violet and/or ultra-violet light) I would expect a UV cut filter to help somewhat, yes. Additionally since a polarizer decreases the amount of \"stray\" light rays which contributes to bloom and haloing, I would expect it to help as well. The reason it\'s considered mostly to be a digital phenomenon is because most films are not nearly as sensitive to the V and UV portion of the spectrum (which is where PF is from) as digital sensors are. I also hear it\'s much worse on CCD sensors than N-MOS or C-MOS ones.

But true PF can all be removed in Adobe\'s Camera Raw or many other processors. Here\'s some links about PF and the removal thereof - either with filters or with software:

http://www.great-landscape-photography.com/ultraviolet-filter.html
http://www.great-landscape-photography.com/remove-purple-fringing.html
http://www.pcworld.idg.com.au/article/75955/removing_purple_fringing/
etc.





May 29, 2011 at 09:25 AM





  Previous versions of Bifurcator's message #9629044 « Filters cutting down Purple Fringe CA? »