D800 + ND = Magenta cast

Images taken with heavy ND filters will occasionally show a strong magenta cast.  Almost all ND filters transmit some infrared wavelengths, and this IR light is one of the primary causes of the magenta cast.  At the same time, some digital camera sensors are more sensitive to IR than others, and in my experience the Nikon D800/D800E twins fall into this group.  However, for most situations there is a simple solution.

My favorite ND filter is the 7-stop Tiffen IRND 2.1 (which I think is an excellent bargain in terms of ND filters).  But even this filter, with has some IR control as part of its design, can result in magenta contamination.  Here’s a frame taken at the edge of a waterfall using this filter and my D800E, with the lens pointing almost straight down.  The resulting image is a worst case example.

 

The solution I’ve found:  close the camera’s eyepiece shutter.  No matter if mirror lockup is used, or the timer delay, or whatever…close the eyepiece shutter.  Under any circumstance, the D800/D800E cameras are very sensitive to light coming through the eyepiece, so closing the eyepiece whenever shooting from a tripod is a good idea.  In the above example, the eyepiece is open and positioned toward the sky.  Here’s another shot, same situation as the previous image, but with the eyepiece shutter closed.  Big difference.

 

9 Comments

  1. John T. April 13, 2014 at 9:28 am #

    Great advice, I had no idea the eyepiece could let in so much light and effect the color cast of the image.

  2. James Doyle April 14, 2014 at 4:01 pm #

    Great tip John, thanks for sharing.

  3. Klaus Schleicher April 16, 2014 at 10:53 am #

    Very helpful tip. Tested it yesterday and it works great.

  4. Andrew McLachlan April 20, 2014 at 1:21 pm #

    Thanks for this useful tip…I encountered similar problems with a 10-stop ND filter in Ontario’s Killbear Provincial Park and did find that closing the eyepiece shutter helped a lot.

  5. ANTONIO BIGGIO April 24, 2014 at 8:22 am #

    Mr. Shaw about using filters in the field: in your books you talk about the use of gnd, but today you continue to use them or like most digital photographer prefer the bracket technique and blending the photos in post production?
    Thank you.

    • John April 24, 2014 at 12:06 pm #

      In the film days I used graduated ND filters. With digital I do not. Masking exposures together yields a much better final image.

  6. Paul April 29, 2014 at 8:04 am #

    If the magenta cast is eliminated by closing the eyepiece shutter, then the problem was light leak, not transmission of IR light by the ND filter, no?
    Could try taking a photo under similar conditions with the eyepiece shutter open, and the lens cap on. Bet you get magenta streaks.

    • John May 12, 2014 at 11:04 am #

      I agree that the problem is caused by a light leak. But with the eyepiece shutter open and lens cap on I do not get the magenta streak. For what it’s worth, I’ve seen this problem with both Nikon and Canon cameras. Of the Nikon bodies, the D800 twins are the most susceptible.