POLARIZER changing color of white wall??

Greg Voevodsky

Greg Voevodsky

Active member
Something strange seems to be going on here.

I'm pointing my EX1 camera at a white wall. Color Balance is set to manual and correctly. Now, when I rotate my $200 circular polarizer by Rodenstock, I get a color shift from light magenta to light cyan passing through white in the middle. What is going on here?

I also tested it with my old Schneider 4x4 pola and got the same effect. I then tested both filters on my PD150 and had NO problems. This a a big problem if you are panning ourdoors as the color shifts are rather dramatic - I've never seen anything like this and was shocked testing it today.

Is there a setting off or something? Can someone explain / fix this? Is this a cmos thing?! I've tried numerous settings both manual and auto white balance on the EX1 and it is still shifting colors.

WHO ELSE IS HAVING THIS PROBLEM?
 
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NO, It's a $200 circular polarizer by Rodenstock 82mm. I also tested it with my old Schneider 4x4 pola and got the same effect. I then tested both on my PD150 and had NO problems. This a a big problem if you are panning ourdoors as the color shifts are rather dramatic - I've never seen anything like this and was shocked testing it today.

So - who else has this MAJOR POLARIZER problem? I shoot water and nature shots so this is a big problem for me.
 
Interesting... I don't know why there'd be color shifting with a polarizer? I will also be doing nature stuff with an EX! so a polarizer will be key to my footage. I'll keep my eye on this thread and see what's up. You'd think something as simple as this would've been brought up before if it's a problem?
 
I've seen this with both linear and circular polarizers on a few 3-CCD cameras. Always magenta.

e
 
Did you allready check the ATW function? cose with my ex1 it changed a couple of times the white balance automaticly without me doing anything...

i would change on the menu from full automaticly ATW to manual so you can use the white balance manually and it shouldn't change anymore....
 
His white balance didn't change. It's the way the polarizer works against prism and 3CCD systems.

e
 
If you're locked off, perhaps. If you are panning outside of the 90° sweet spot, then you might get a magenta shift. I've had it on my HVX with a linear polarizer on some days, but not others.

I don't know if there is a "trouble" color temperature (e.g., some days are way over 6500K), but I have only seen it on the HVX and linear polarizer on some days shooting. It is intermittent.

e
 
I just tried it with a 3rd polarizer and the effect is a bit less but still there. I can manually white balance but as soon as I again turn the pola or pan the camera I get this horrible unnatural green or magenta tint. I would not mind if was more warm/cool - but its not is green and magenta.

CAN MORE PEOPLE TEST THIS WITH THEIR CAMERAS PLEASE?! THANKS.
 
I finally chalked it up to a rule on 3CCD cameras. Moving off the polarizing axis can induce color shift when using prism and multi-CCD cameras. It isn't only on my HVX. It isn't only on 1/3" cameras.

If you treat it as a rule, you'll be more comfortable with it. Just like tilting when using a grad filter. Know your limits kind of thing.

e
 
I tried it today and there's a slight shift between cyan and magenta. I can compensate with a manual white balance. And as Erik mentioned, as long as you know the limitations you can develop a work-around.
 
DCSensui said:
I tried it today and there's a slight shift between cyan and magenta. I can compensate with a manual white balance. And as Erik mentioned, as long as you know the limitations you can develop a work-around.
Click to expand...

Oh.. I'm sorry to hear that. Thanks for the test. However, if you are panning with a polarizer than you are going to see it. The only work around is 1. NOT TO PAN or 2. REMOVE THE POLARIZER - however, now you loose your saturation, and reduced glare - especially on water.
 
People obviously successfully pan using video cameras and polarizers, what are they doing different to prevent color shifting?
 
DCSensui said:
I did some panning and it looked OK. The pan covered 30 or 40 degrees of the horizon.
Click to expand...

Ok, there is something up with a magenta/cyan color shift. This is not a warm/cool - colorbalance shift.

Now, there might be a work around with limitations, but lets first get the problem clear.

I've tried 3 different circular polarizers by Schnieder / Tiffen / Rodenstock.
Each filter was manually and properly color balanced - making white / white.

Now rotating the filter causes a slight 5-15% my guess shift toward magenta and then back to cyan... (or purplish or greenish in english). THIS SHOULD NOT HAPPEN.

Now, you can compensate - re-color balance the magenta back to white (with the glare reduction that you want) and it will work - until YOU PAN or Rotate the filters. Again, this should not happen.

Also, I am not use to having to re-color balance every time I turn 90 or 180% on an ocean beach / sunset - and watching my colors go to a hellish green or magenta.

I'm waiting to get my new Mac - so I will be posting clips and or sending the camera back to Sony.

I have shot wildlife - seals swimming underwater from above with a pola to remove the glare with no problems with my old PD-150 ... now image color shifts appearing in the water. If I remove the pola the glare makes the shot impossible. There is NO FULL workaround as of now... except in costly post.
 
Hmmm... I am just days away from getting my EX1, maybe even two, but if there is a problem with circular polarizers and the EX1, I can't pull the trigger because 99% of my footage will be wilderness stuff using polarizers and GND filters. If everytime I merely pan the camera there's a shift in colors, then this camera is not for me. I understand how the angle of the sun affects polarization (I'm a photographer), but there shouldn't be any shifting in "colors", just the effect of polarization. Has anyone else heard about this? I've been on a lot of forums and I've never heard it mentioned, but I don't know if people are shooting it outdoors much with a polarizer.

There doesn't seem to be anyone here shooting much with a polarizer (or at least responding to this thread if they are), so I'll have to ask Sony (not even sure how to get a hold of them) if this is a known issue with this camera?
 
Sony contact for PMW-EX1 questions

Sony contact for PMW-EX1 questions

email this person at Sony

"Bierschenk, Doug" <Douglas.Bierschenk@am.sony.com>



Douglas Bierschenk
Product Support Specialist
Product Operations Support Center
Sony Electronics Inc.
Tel: (800) 883-6817
Fax: (201) 833-5210

Professional Services Website:
www.sony.com/professionalservices
 
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