Luminous Landscape Forum

Equipment & Techniques => Beginner's Questions => Topic started by: wofsy on December 02, 2013, 12:15:08 pm

Title: Color Correction for Polarizers
Post by: wofsy on December 02, 2013, 12:15:08 pm
I was recently taught to use a polarizer to increase saturation. This works but the tint of the polarized blue sky seems odd and I wonder if there is a way to return it to a natural looking blue.
Title: Re: Color Correction for Polarizers
Post by: hjulenissen on December 02, 2013, 01:25:49 pm
I do color profiles of my cameras using X-rite Colorchecker passport.

I have tried profiling my various filters as well (on "regular", non-polarized target), and frankly I find that the difference is small enough that I don't bother. When I want really neutral color, I seldomly need a filter, this could also contribute to my feelings.

-h
Title: Re: Color Correction for Polarizers
Post by: Christoph C. Feldhaim on December 02, 2013, 01:44:02 pm
If possible you could take 2 shots from tripod - one with and one without the polarizer and blend them later.
Title: Re: Color Correction for Polarizers
Post by: Slobodan Blagojevic on December 02, 2013, 01:55:17 pm
The  very reason people use polarizers for sky is to get that deep, dark blue tint that you call "odd." Quite easy to get rid of it: do not use a polarizer, or do not use it at full strength.
Title: Re: Color Correction for Polarizers
Post by: Ken Bennett on December 02, 2013, 02:21:17 pm
I've seen some odd tints coming from polarizers -- not just the deep blue of the polarized sky, but a color cast that suggests the filter is not entirely neutral. Owning several different brands of polarizers, I do see some differences in the final color output.

Two options:

1. Shoot raw files and fix the color balance in the raw converter. This fixes the majority of issues.

2. Use the Hue/Saturation/Luminance sliders in Lightroom or Camera Raw to adjust the specific sky color. I find this sort of tweak can make a significant difference in some situations, including odd color casts from filters.
Title: Re: Color Correction for Polarizers
Post by: wofsy on December 04, 2013, 10:03:17 am
In my opinion, the saturated blue skies have an unnatural shift in tint. I have no problem with intense deep blue. But the shade that one gets is often surrealistic. It would be nice to have a mapping of hues to be able to restore a natural color.
Title: Re: Color Correction for Polarizers
Post by: Alan Klein on December 04, 2013, 10:39:07 am
Can't you just adjust the hue slider a little in the blue channel or something similar to get the blue you want?
Title: Re: Color Correction for Polarizers
Post by: Slobodan Blagojevic on December 04, 2013, 11:46:53 am
I have yet to see a polarizer with a color cast (other than the deliberate kind - warm polarizer, for instance, or dual-color ones). Maybe I should try cheaper ones? Strong neutral density filters often cause color shifts, and some graduated ND as well - Cokin is known for that. But a polarizer?

As for "restoring natural color"... the purpose of a polarizer is to create a surrealistic, unnatural sky color. What would be the purpose of using it if you want to reverse (restore) its very effect?
Title: Re: Color Correction for Polarizers
Post by: wofsy on December 04, 2013, 04:09:25 pm

When shooting in miidday the polarizer adds saturation and cuts reflections. I do not use one at sunrise.

I have tried using sliders but to no avail. The shift probably involves several sliders.
Title: Re: Color Correction for Polarizers
Post by: Slobodan Blagojevic on December 04, 2013, 04:14:26 pm
At this point, the only helpful thing would be to post an example, so that we can see what we are talking about.
Title: Re: Color Correction for Polarizers
Post by: jferrari on December 04, 2013, 04:41:13 pm
Exactly where are you seeing the problem? On your monitor? Printer? Laptop? Ipad? Cellphone? Projector? Have you performed any calibration on these devices? More info please.      - Jim
Title: Re: Color Correction for Polarizers
Post by: langier on December 26, 2013, 11:26:14 am
Shoot one pix and one pix without the polarizer with your digital gray balance card to correct the color bias if any. To not saturate the sky as much, don't max-out the twisting of the polarizer. No need for two photos.

Today I seldom use a polarizer. If I need a bit darker sky, I tweak in post production. Faster and more control there.