Blocking viewfinder while using remote or timer?

Discussion in 'Digital Photography' started by CarlsonCustoms, Jan 24, 2009.

  1. CarlsonCustoms macrumors 6502

    Joined:
    Mar 5, 2007
    #1
    Hey guys I finally got around to reading the D90 manual. I noticed it says to remove eyepiece and replace it with the blockoff plate when you are using the remote or timer. It says the light let in (becuase your face isnt there) can mess with the exposure.

    Does anyone do this in practice? It seems like a hassle to do that but then again I was looking at the lens the other day and clearly saw the light from the viewfinder visable.

    Any ideas?
    zack
     
  2. thr33face macrumors 6502

    Joined:
    May 28, 2006
    #2
    of course you can see the light coming in if the mirror is down.

    when not taking an exposure the light goes through the lens, bounces off the mirror and then to the viewfinder.

    when the camera is exposing the mirror flips up and the light goes through the lens and then hits the sensor.


    I never use the viewfinder cap, i don't even know where it is.
    I imagine that the mirror does not perfectly seal the light-path from the viewfinder and if a strong enough light shines into it, some might find it's way to the sensor and cause loss of contrast.
     
  3. thr33face macrumors 6502

    Joined:
    May 28, 2006
    #3
    edit: oh wait, I guess I am an idiot ;)

    light that gets in from the back messes up the automatic exposure reading ...
    it only came to me now after i did this "test". ...
    i alway use manual settings when i'm using a self timer or the remote, therefore i never noticed it.




    I just did some non-scientific "testing" with a nikon d40.
    Both shots are 30 second exposures at ISO1600. Both shots have +10 stops of exposure and -0.1 offset applied in photoshop. that makes them ultra unrealistic high iso1638400.

    first image: lens cap on, camera under thick blanket => absolutely no light.
    [​IMG]

    second image: lens cap on, camera on table, bright fluorescent lamp directly at viewfinder.
    [​IMG]

    Observations: the two "bright" areas in the upper left corner are amp-glow. Those are normal.
    The horizontal bands are normal too.

    The second image has one "bright" area in the center right that could result from the light source. In general number 2 is "brighter"

    Of course, since I only took 2 exposures, this "result" could be a normal sensor data variation.
     
  4. CarlsonCustoms thread starter macrumors 6502

    Joined:
    Mar 5, 2007
    #4
    interesting.. maybe i'll take a few sample shots with normal, normal with light behind viewfinder, and viewfinder blocked
     
  5. AlaskaMoose macrumors 65816

    Joined:
    Apr 26, 2008
    Location:
    Alaska
    #5
    Camera manufacturers include a rubber or plastic piece to cover the viewfinder, and explain the reasons why you should use it. It's in the owner's manual, and for good reasons. When looking through the viewfinder, your eye and rest of the face is serving as the plastic piece (blocking unwanted light from behind the camera). Using it is very important when taking photos of Northern Lights, for example, where this "unwanted light" can screw-up your photos. The damage to your photos is a lot more noticeable when taking long exposure photos in the darkness of night.
     
  6. jbernie macrumors 6502a

    jbernie

    Joined:
    Nov 25, 2005
    Location:
    Denver, CO
    #6
    Not sure how it is packaged on the Nikons but for Canon they have it on the included neck strap so it is nice and handy.
     
  7. CarlsonCustoms thread starter macrumors 6502

    Joined:
    Mar 5, 2007
    #7
    yes its included in nikons.. I was specifically asking if it really makes a difference in day to day useage

    Zack
     
  8. jbernie macrumors 6502a

    jbernie

    Joined:
    Nov 25, 2005
    Location:
    Denver, CO
    #8
    It probably falls under one of three categories....

    1) it does make a difference so it is included as part of the standard accessories

    2) the plastic bit is so cheap so you may as well toss it in regardless, even if Joe Average doesn't use it they at least have it.

    3) because it is so cheap they would look cheap themselves if they didnt include it.
     
  9. Vogue Harper macrumors 6502

    Vogue Harper

    Joined:
    Nov 16, 2008
    Location:
    Serenity
    #9
    Does using mirror lock-up help in this regard i.e. blocking light entering via the viewfinder? Or is the point of mirror lock-up in long exposure photography solely to negate the shake caused by the mirror coming up when the shot is taken?
     
  10. Cliff3 macrumors 65816

    Cliff3

    Joined:
    Nov 2, 2007
    Location:
    SF Bay Area
    #10
    No and yes, respectively.

    FWIW, the pro bodies (D1/2/3/700) have shutters to close off the viewfinder eyepiece, so it''s a bit more convenient.
     
  11. CarlsonCustoms thread starter macrumors 6502

    Joined:
    Mar 5, 2007
    #11
    Well here's an observation..

    Today my whole family got together and we wanted a family portrait. We all setup on teh wall across from a window (so they were frontlit) and my camera on a tripod was in front of the window. While taking test shots with my face on the viewfinder the shots looked great. As soon as I switched it to remote release and went out infront of the camera all my shots came out pitch black!

    The only solution was to close the drapes to block the sun and use a piece of paper to block the viewfinder (didnt have the eyepiece block plate with me).

    Convinced me to use the blockplate. I'll just use liveview to focus and frame the shot and then use remote.

    Zack
     

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