Metering- reflectivity vs tone? (i.e. black objects in shadow)

Discussion in 'Lighting' started by GarageBoy, Aug 21, 2013.

  1. GarageBoy

    GarageBoy Member

    Messages:
    652
    Joined:
    Nov 5, 2012
    Shooter:
    35mm
    So question about metering
    I know meters are tuned for midtones and thus, something darker than midtone will reflect less light and lead to overexposure and vice versa and you thus compensate accordingly

    I also know that according to Zone system techniques, that you can place highlights in approx +2 for slide (meter highlights and open 2 stops) and the darkest part you want details in (shadows) in -2 (meter shadows and close down 2)

    But what happens if that highlight is dark toned (if that makes sense? i.e. black detail being rim or edge lit)
     
  2. jp498

    jp498 Member

    Messages:
    1,463
    Joined:
    Oct 5, 2009
    Location:
    Owls Head ME
    Shooter:
    Multi Format
    Use an incident meter and it won't matter what tone your subject is; (just measure the light rather than reflectivity)
     
  3. markbarendt

    markbarendt Subscriber

    Messages:
    7,726
    Joined:
    May 18, 2008
    Location:
    Beaverton, OR
    Shooter:
    Multi Format
    GarageBoy you have identified the biggest challenge with reflective metering.

    Black is dark whether in full sun or shade so if you meter from a black subject then you would open up the camera. Meter from white close the camera some.

    The more challenging question is how much, not all blacks, or whites, are created equal and 2 is not always the answer.
     
  4. benjiboy

    benjiboy Subscriber

    Messages:
    8,699
    Joined:
    Apr 18, 2005
    Location:
    U.K.
    Shooter:
    Multi Format
    If you compare by metering the black subject with an 18% Grey Card in the same light it gives you a pretty good idea how much to compensate.
     
  5. markbarendt

    markbarendt Subscriber

    Messages:
    7,726
    Joined:
    May 18, 2008
    Location:
    Beaverton, OR
    Shooter:
    Multi Format
    Sure, but if you have and are using a reference point in the scene to correct/check your exposure offset, a grey card or whatever, then the offset to shadow or highlight becomes irrelevant.
     
  6. jeffreyg

    jeffreyg Subscriber

    Messages:
    1,412
    Joined:
    Jun 12, 2008
    Location:
    florida
    Shooter:
    Medium Format
    GarageBoy and others who may not be familiar with it,
    A frequent APUG forum contributor Ralph Lambrecht has coauthored a book "Way Beyond Monochrome" that is a comprehensive reference on black and white photography and well worth adding to your library. Among all the detailed information, you can find how to build a zone dial.(pages 468-469)

    http://www.jeffreyglasser.com/
     
  7. MattKing

    MattKing Subscriber

    Messages:
    17,191
    Joined:
    Apr 24, 2005
    Location:
    Delta, BC, Canada
    Shooter:
    Multi Format
    You take your reflected light reading from the area you are interested in, and then adjust the exposure to give you the tone you are looking for.

    The challenge may be actually limiting the area read to what you want to evaluate.
     
  8. Poisson Du Jour

    Poisson Du Jour Member

    Messages:
    4,328
    Joined:
    Jul 1, 2008
    Location:
    Geelong/Richmond Vic AU
    Shooter:
    Multi Format
    Spot meters are reflective meters, but their narrow angle of view (typically 1° to 5°) means they are excellent for isolating specific areas — as Matt King said in his second sentence, "actually limiting the area read to what you want to evaluate", or put another way, analysing all principal luminances, in the first instance not assuming the scene presented before you or the meter is "average".
     
  9. GarageBoy

    GarageBoy Member

    Messages:
    652
    Joined:
    Nov 5, 2012
    Shooter:
    35mm
    Thanks, I think I just need to get a spot meter and experiment
    The 40deg reflective attachment on the Flash Meter IV is not selective enough and I think it simply averages