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Shutter/Exposure question: In arena lighting.. under exposed areas of the frame.

Steve_VSteve_V Member
edited October 2011 in general photography
Twice now in public arena in full manual with colour temperature set I have had strange results. I think the lighting is mercury vapour and might be pulsing at a shutter speed of 1/500 a second. At first I thought my shutter was developing issues, but in the arena I can produce the issue and the camera seems works fine outside of the arena.

I'm seeing under exposed areas of the frame in a form of a vertical shadow. Nothing is between me and the ice and the effect looks like lighting might be off above the shadow. Much of the frame is exposed properly.

If I take 20 shots about half of them have this effect and the rest of them are perfect when shooting at fixed point in various tests.

I suspect its a shutter issue but wish I could reproduce it outside of the venue.

Comments

  • Do you have pictures you can attach to this thread, so we can see what you are talking about?

  • Here's an example of what I am encountering.
    Thanks

    Steve
  • TrevTrev Moderator
    Steve,

    I may be wrong but to me that does not look like a shutter/exposure problem, it looks like a form of color contamination. 1674 starts off with a reddish hue almost across entire frame, 1675 it's on the left side and 1676 on the right hand side.

    Are you sure there is no fancy lighting above, as in a moving light source, since the images all look consistently exposed, just that the color hue makes it look slightly underexposed, red being a darker color then white.

    The other thing, are you shooting in Auto White Balance, if so any small change in light source can affect the outcome, although I should not think to that extent.

    If you did not experience anything outside the arena, and you can duplicate this inside arena almost at will, then there is something inside causing it obviously.

    . . . another test, get a large sheet of white paper with a little black cross in middle for you to focus on something, pin it against something in a consistent light source, set your camera up on tripod, set a WB, not auto, and Manual Exposure, not any of the Auto functions, make sure the paper fills the frame entirely with the little black cross dead center, take lots of shots, 50 + at least, if you see any of the same banding/change then there will be something wrong, if all the shots look consistent, nothing to worry about.

    Trev.
  • Neil vNNeil vN Administrator
    I'm not sure about Mercury Vapor lamps, but with fluorescent tubes, you get a type of color flicker similar to this. The fluorescent lamps cycle at 60Hz ... which means that at certain shutter speeds, you'll get a weird color banding that comes and goes throughout sequences of images.
  • The Nikon D700 is okay, after doing many white paper tests. This "effect" only seems to happen at the ice rink. Over the next month I'm going to vary shutter speeds and locations in the rink as time permits.

    Thank all for your input and if I find something solid to report back I will.
  • TrevTrev Moderator
    Good re camera, thought it would be, since you had no trouble outside rink.

    Let us know.
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