Page 2 of 2 FirstFirst 12
Results 21 to 26 of 26

Thread: shooting black object

  1. #21
    Senior Member
    Join Date
    Jun 2003
    Location
    Here
    Posts
    3,779

    Default Re: shooting black object

    Quote Originally Posted by student
    As jOhO mentioned, there is some ambiguity in the way the question was phrased.

    I am really not sure if I got the question correct. Was he trying to photograph a black cat? Or was it that the cat (whatever "degree of lightness" it was) turned out black? I assume the more likely one is the former, because he was trying to shoot some "black object".

    Looking at the posts/replies, I think sweat100 got it most correctly, although his advice to underexpose by EV-1 to -2, (or overexpose by +1 and +2 for snow) is being too cautious. Eventually will work, but -1 is not too correct.

    If one wants to take a picture of a black cat so that the cat turns out properly black, he should underexpose by 2 stops. I am afraid that Stoned got it completely wrong. And if espn wants to photograph white snow, then he should overexpose by about 2 stops. While Spectrum's approach will eventually get the correct picture, it shows a lack of understanding how light and meter work together.

    sweat 100, shinken, and canew had explained the gist of the exposure. And Isisaxon's advice of using an incident meter should also work fine.

    To explain why one should underexpose by 2 stops for a really black cat, and overexpose by 2 stops for really white snow, I have to revert once again to the zone system.

    When one meters a black cat, the meter detects the cat to be too dark. The meter is calibrated to make everything grey. So it increases the exposure to make the cat grey. And when one meters for the snow, the meter detects the scene to be too white, and reduces exposure to make the snow grey.

    Why 2 stops +/-?

    The zone system gives a very simple guide to understanding tones. At the middle (which all meters are calibrated to) is 18% grey/middle grey. This is zone 5.

    Zone 4 is more grey. And zone 3 black but with discernible texture. Zone 2 completely black with no texture. Zones 1 and 0 very, very black.

    Zone 6 is lighter than 5. And zone 7 white, but with discernible texture. Zone 8 white with no texture.

    Using the black cat, if one underexpose by 1/3 stop, one is hardly doing anything. Underexposing by 1 stop will make the cat a dull neither here or there "black". Underexposed by 3 stops will make the cat completely black with no texture. So the "correct" exposure for a black cat should be minus 2 stops.

    The same principle will apply to photographing snow, but in the reverse direction.
    Never more than agree with you bro. Do always remember that the camera's metering system is somewhere at 18% grey regardless of whatever subject or scene you are metering at.
    Just picture your colour image into black & white & you are somewhere there already. And do know the zone system well too in order to guess what/where to meter for better exposure for the entire picture you're going to take.
    Bracketing is still a must if you want to achieve the best results.

  2. #22
    Senior Member
    Join Date
    Jun 2005
    Location
    SGee
    Posts
    1,572

    Default Re: shooting black object

    i hope d thread starter can "shed some light abt d intended effect he's aft"...

  3. #23
    Senior Member
    Join Date
    Dec 2004
    Location
    NTU and Wdls
    Posts
    2,622

    Default Re: shooting black object

    Er... The camera doesn't meter for 18% as neutral.

    The 18% grey thing is really a bit of a myth, it is a "standard mid-point" of exposure that I think was first mooted by Ansel Adams (wiser heads will put me right on that). In fact camera manufacturers set their exposure meters up to assume the scene they read is 13% grey, because 13% is closer to the real "average" scene reflectivity (whatever average is). If you set a camera based on metering off an 18% grey card then your exposure will be out a whisker for the real situation of the 13% average scene, the difference is not much and will never be seen by print workers, and slide workers should adjust the ISO setting of their cameras until they get the results they like for that particular film, so that adjustment makes things right anyway. The 18% grey card is 18% reflectivity, it's just that cameras assume the scene is 13% reflectivity. Just a bit of technical fluff to clear the air about the sacred 18% grey issue.
    from http://homepages.ihug.com.au/~parsog...tmetering.html


    "Using the 18% gray card as a metering reference will cause approximately 1/2 stop underexposure as the reflected light meter is assuming 12%."

    Check out the link below.
    http://www.bythom.com/graycards.htm
    and
    http://www.richardhess.com/photo/18no.htm

  4. #24

    Default Re: shooting black object

    Quote Originally Posted by unseen
    Er... The camera doesn't meter for 18% as neutral.


    "Using the 18% gray card as a metering reference will cause approximately 1/2 stop underexposure as the reflected light meter is assuming 12%."
    Whoever wrote this might be right that meters might not be calibrated to 18% gray. I am not going to challenge his statement. But I will give a few comments for your considerations.

    1 I have a spotmeter specifically calibrated to 18% gray. I had "tested" this spotmeter to my Leica R6.2, Canon 1V, as well as Contax 645. My conclusions? Remarkably, the spotmeter reading in my calibrated spotmeter is almost identical to the reading from the Leica, Canon, and the Contax 645.

    According to the writer you quoted, the Leica, Canon, and Contax reading should be different from my calibrated spotmeter, but they are not.

    2 I have no idea who this writer is, nor what his photography is like. But innumerable photographers had used the idea that meters are calibrated to 18% grey, and made beautiful images. Of course there are more things to consider than the spotmeter to make the images. But in their use of the meter, they adhere to the 18% gray concept.

    When I want to learn how to sail, I take lesssons from sailors. I do not take lessons from cartographers.
    Last edited by student; 7th March 2006 at 10:09 AM.

  5. #25
    Senior Member
    Join Date
    Dec 2004
    Location
    NTU and Wdls
    Posts
    2,622

    Default Re: shooting black object

    Thanks.
    For me, I'm just taking it as a GK. I've a spotmeter, but I don't use it (hahaha.. maybe that's why my photography sux..) The lightmeter in my dSLR suffice for me, I do the rest when converting RAW.
    I do remember hearing this from some seminars else b4, so thought I'll throw it up.

    When I want to learn how to sail, I go out to sea. I do not sit in class.

  6. #26

    Default Re: shooting black object

    Quote Originally Posted by unseen
    When I want to learn how to sail, I go out to sea. I do not sit in class.
    Wonderful! And if you are a newbie in sailing, make sure you have a sailor around.

Page 2 of 2 FirstFirst 12

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •