Corner darkening vignetting

Discussion in 'Beyond the Basics' started by Rob, Mar 31, 2005.

  1. Rob

    Rob TPF Noob!

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    Hello people,

    Just a quick question - with a fixed standard lens on a camera, is it possible that darkened corner vignetting has happened as a result of crud round the edge of the lens, or not? Do you think it's more likely to be a result of something else.

    All appears well with the camera, and it doesn't have a lens hood, but it was properly filthy and I didn't have time to clean it before a test film. It was a very bright day and the pictures were a touch under-exposed.

    Thanks in advance

    Rob
     
  2. Artemis

    Artemis Just Punked Himself

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    I dont know to be honest, but I would say it was crud around the lens...especially if it was under exposed..because perhaps the metering system meterd for the dirt and underexposed the picture...only answer I can think of :)
     
  3. ksmattfish

    ksmattfish Now 100% DC - not as cool as I once was, but still

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    Typically I would say it's because of a lens hood or stacked filters, but I suppose it could be from crud around the edges of the lens. Particularly at wide apertures.
     
  4. Christie Photo

    Christie Photo No longer a newbie, moving up!

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    This sounds right to me too. I really doubt it's from crud though. I think that would result more in a bit of diffusion if the crud is on or in the lens.

    When you say "standard," do you mean normal focal legnth? Is the lens from a quailty brand maker?
     
  5. Hertz van Rental

    Hertz van Rental TPF Noob!

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    Make sure the lens is on the body properly - some cameras it's possible for it to work even though the lens isn't mounted quite right.
    Also look to see if the front or back element has come loose. If it has a screw in locking ring these can undo slightly. With most 35mm lenses everything is done to close tolerance so anything out or loose by even a fraction on a lens can cause vignetting.
    Dirt on the lens wouldn't cause it - unless it's got something like back paint on it!
    As for the exposure. Is there a meter in the camera and did you use it? Crud on the lens wouldn't make a difference but there might be some inside on the sensors.
    Before you fiddle around there though, give it a thorough clean, change the meter battery and check it against another meter.
     
  6. Rob

    Rob TPF Noob!

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