Q: Dealing with exposure (compensation)?

Discussion in 'Digital Video' started by wiseguy27, Jun 17, 2005.

  1. wiseguy27 macrumors 6502


    Apr 30, 2005
    [Note: I'm light years away from being an expert on video. This is a very basic question, and I believe the answer might be pretty simple too.]

    I have used camcorders only in a few occasions (and not extensively). All camcorders and digital cameras nowadays provide automatic exposure compensation, wherein the device automatically changes the exposure based on the amount of light coming in. When I shoot still pictures with a digital camera, this change in the exposure compensation is easy to deal with because I allow my camera to "settle in" and then I manually change the aperture or AE lock setting to suit how I want to capture the picture.

    How do professionals deal with such situations with video? Do they even use automatic exposure compensation in camcorders? If so, how would they deal with, say the following situation - while shooting something within a house, the camcorder is slowly moved around and in a few seconds passes over a glass window (or open door) in broad daylight, causing a sudden change in the amount of light (and thus upsetting the device's automatic exposure control if in automatic mode)? If not, how would they adjust the controls while shooting such a varying light situation?

    For a "planned" video (where the shoot is not continuous), I can think of using the same "settling time" to manually adjust the exposure and continuing with the shoot. For a spontaneous "live" one, I don't have any idea how to deal with this - the best that I can think of is to neatly chop off the "flaring transitions" while editing. ;) Is there a better way?

    Additionally, any good pointers, information and book/resource references about shooting good quality videos would be appreciated. :)

    P.S.: My main use for a camcorder (in the future) would be to shoot home videos, travelogues and "home made documentaries".
  2. LethalWolfe macrumors G3


    Jan 11, 2002
    Los Angeles
    As a rule of thumb pro's use automatic nothing when shooting. The example you gave in regards to auto-iris (exposure) is exactly the reason why pro's don't use auto-iris (that and it tends to either under or over expose the image depending on the camera model). Another example of auto-iris messing up is like this: Let's say you have a locked down shot of two people talking in front of the street on a sunny day. If a car drives by and reflects sunlight into the camera the auto-iris is gonna go "Oh crap, I'm over exposed" and dial down (thus underexposing the people you are shooting), but a split second later when the car passes the auto-iris is gonna go "Oh crap, I'm under exposed" and dial back up to the proper exposure. Wash, rinse, and repeat for every shinny object that reflects light into the camera.

    The best thing you can do is get a camera w/as many external manual controls as you can. That way as you go from dark-to-light/light-to-dark you can adjust the iris as needed. And w/a bit of practice you can make it a very smooth adjustment. And I say "external" cause a menu driven control is just about useless 'cause of the time it takes to dig thru the menu system to get to it.

  3. wiseguy27 thread starter macrumors 6502


    Apr 30, 2005
    Exactly! Since I've seen my digital camera trying to adjust this way, I couldn't even imagine how much worse it would be in videos!

    I guess this is one reason why the touch screen Sony (consumer) models may not be appropriate for me (I'm just guessing that they have the exposure setting also buried in the on-screen menus).

    Thanks for your response and suggestion.
  4. Sharewaredemon macrumors 68000


    May 31, 2004
    Cape Breton Island

    Yeah I use a JVC low end camera (can't afford the VX2100 of my dreams).

    And LeathalWolfe is right, what i usually do is lock the iris after I set the exposure, and then I get the best picture.

    Another thing you can do with a low end camera is leave the exposure setting up at all times so you can adjust on the fly.

    Though it's still easier with a prosumer camera.

Share This Page