ND filter with EP2 giver red cast

[raid]

ND filter with EP2 gives red cast


I tried today to use a Vivitar Series 1 ND MC filter with an E-P2 and Zeiss 85/1.4. All images had a reddish cast. When I remove the ND filter, this red cast goes away. Is this problem due to the ND not matching the sensor well or is it an ND that just has such a red cast? ND filters are not supposed to add color. Is anyone here using an ND filter with an EP camera? This is a surprise to me. I used in the past Singh Ray ND filters with slide film, and I have never seen such a color shift.

 

[emayoh]

Haven't used an ND filter with that camera, but most ND filters that I have used with other digital sensors definitely have various amounts of color shift. I have yet to find one that is truly neutral. Are you using a custom white balance? Using a grey card can help in post process.

Sorry if you have already tried these things. Good luck.

 

[raid]

Hi Mick,
What do you mean by a custom white balance?
I have not tried anything so far, but there is a strong red cast. My feeling is that this ND filter produces a color shift with this particular digital camera. It would work well with B&W images with the EP2.

 

[JoeV]

I was surprised to find my favorite polarizer filter was also giving a subtle color cast to images. I didn't notice this until I started experimenting with setting custom white balance on my Lumix G5 via a white card. Using the white card I was able to compensate completely for any filter color cast, such that you can't tell apart the images taken with and without filter.

I also found visible color casts from two different system lenses. The lesson I'm learning is to set white balance manually using a card after changing lenses, or when the light changes.

~Joe

 

[raid]

Hi Joe,
I have never before read anything about color shifts with ND filters, so this is quite informative to me.

Both you and Mick recommend a white balance, which is something that I must do next.

 

[raid]

This is not easy at all. I am trying to do the white balance.

 

[Gabriel M.A.]

Answer: IR light.

When you use an ND filter with a digital sensor, the limitations of the IR filter become evident: there is an "accumulation" factor of IR light which is proportional to the time length of the exposure.

I suggest you turn off the auto white balance and set it to something "appropriate" (if outdoors in plain sunlight, set it to Daylight, if cloudy, to Cloudy, etc.) when taking the photo. Further WB correction(s) during post-process are likely to be needed.

 

[raid]

Thank, Gabriel. I am leaning towards this approach for color images. Still a pain ....
By the way, I am not using the M8 here, but an Olympus EP2. Why is there an IR factor?

 

[david.elliott]

Color casts with strong ND filters is just part of the game.

http://www.redbubble.com/people/pet...the-ultimate-guide-to-neutral-density-filters

 

[raid]

Thanks for the interesting material on extreme ND filters. The one that I used is not extreme. I have an ND8.

http://www.ebay.com/itm/Vivitar-67m...141&pid=100005&prg=1125&rk=4&sd=130725559933&