Testing a Camera's Image Quality?

Discussion in 'Medium Format Cameras and Accessories' started by dancqu, Sep 11, 2008.

  1. dancqu

    dancqu Member

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    The test of any camera's image quality is the
    negative produced. I've not mentioned the lens
    itself as it is one component of a mechanism for
    recording an image.

    I know there are resoluion targets available. I've
    no official types on hand. How and what other
    method and material would work well?

    I'm meaning to find out one way or another if my
    RZ and it's three lenses have me any ahead in print
    potential over that of my ETRSi and it's two lenses.
    And if ahead, is it enough so to warrent packing
    the RZ's extra bulk and weight. Dan
     
  2. Lee L

    Lee L Member

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    Here's a good place to start if you want to generate a test target to shoot and quantify resolution.

    http://www.normankoren.com/Tutorials/MTF5.html

    Helps to have a good printer with these charts, but you could also put them on a CD or flash drive and have a copy shop print them on a good hi-res printer if you don't have one yourself.

    Lee
     
  3. JBrunner

    JBrunner Moderator Staff Member Moderator

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    When I test a camera I usually shoot a slow E-6 emulsion. The process is consistent, super sharp, and chromes tend to readily reveal any deficiency.
     
  4. keithwms

    keithwms Member

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    Slap some velvia or astia slides on a projector....
     
  5. Lee L

    Lee L Member

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    This is what I do, with slow film as Jason mentions, shooting what I'd shoot anyway, not resolution charts. However, you have to be sure your projection lens is up to it. Many aren't, especially the common zooms. Cheap projector lenses are bested by a good loupe.

    Lee
     
  6. Q.G.

    Q.G. Inactive

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    Whatever you do, put your cameras on a tripod. Use prerelease. And a cable release.
     
  7. ricksplace

    ricksplace Member

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    Test targets are often required to be shot at a close distance, when the lens may not be at its best. I prefer a large brick wall. Easier to detect distortion (barrel, pincushion, etc) and the resolution can be assessed by the resolution level of the texture of the brick. Just my .02
     
  8. weasel

    weasel Member

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    My method of comparing lenses is to take five pages from a newspaper, tape them to a wall in open shade, in a square pattern ( or rectangle),with one sheet in the middle. Make the square big enough so that it fills the frame with the camera about 10 feet or so from the wall.
    Use a beefy tripod, cable release, mirror lock up, etc. Go to the trouble of making sure the camera is dead on parallel to the wall.
    Use a really sharp film-my personal preference for this is to use one of the c-41 b&w films. They resolve at high levels, and grain won't be an issue.
    Shoot away- different f stops, different lenses, different films/developers, etc can be compared this way. Enlarge the dickens out of the negatives, and see what you can read.
    If you have already settled on a film/developer/enlarger combo, I would use that. What you are trying to do is compare one system to another under your conditions.
    I will be very interested in what you come up with.
     
  9. Fred Aspen

    Fred Aspen Member

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    Newspaper on the wall, 25X the focal length of the lens, lighting of your choice (I use strobe), on tripod, make an 8X print of each, examine the print with a Hastings 10X triplet. You will know shortly which is best. You have to test the entire system, all the way to the print.

    BTW, my Hassy beat the ETRSi (80mm vs. 75mm) under these conditions (only by the smallest of subjective margins) but normal viewing of the prints wouldn't swing the vote either way. The ETRSi is so much more compact and easy handling, it just feels right in the hands. Sorry, Hassy!

    The bottom line is the print because that is what I always judge, since all I do these days is B/W.

    Just my .02,

    -Fred
     
    Last edited by a moderator: Sep 12, 2008