Expoure bracketing, mettering for the highlights

Discussion in 'Photography Techniques' started by Dani Solatie, Jan 4, 2011.

  1. Dani Solatie

    Dani Solatie New to SC

    Oct 18, 2010
    Hi everybody, happy new year!

    I was thinking without actually experimenting this yet, a procedure to bracket different exposures protecting the highlights, ir order to avoid blown highlights in contrasty scenes, and then do hdr as low into the shadows from there.

    1. Spot meter the brightest part of the scene, for example some white clouds in a landscape.

    2. Compensate the exposure at +2 ev.

    3. Bracket the exposure at +-2 ev.

    So, with the exposre compensated and bracketed, you will end up with three images at 0, +2 and +4 ev, being 0 the exposure you metered in the clouds, and two longer exposures that will allow you to get details from the shadows.
    This way you know that the darkest of the exposures will retain as much info as possible in the highlights.

    Am I right or am I missing something? Do you think this should work?

    If the camera allows bracketing a wider range, for example +-3 ev, you could compensate the metered exposure at +3 ev, and bracket at +-3 ev, going deeper into the shadows.

    What do you think?

  2. BBW

    BBW Administrator Emeritus

    Jul 7, 2010
    betwixt and between
    Real Name:
    Dani, some cameras come with an option to bracket. I'm not the greatest at explaining technical how tos, but if you're using the highlights and want to make sure they are not blown... Say for example a sunset with bright sunlight coming out from behind clouds...and you have a darker foreground then you will probably be wanting to do a negative exposure compensation, not a positive one.

    Hopefully someone who is better at explaining the different options will add in their expertise. F stops come in to play, of course, too - as does ISO.
  3. Wally Billingham

    Wally Billingham SC Regular

    Nov 27, 2010
    Laurel, MD
    when shooting negative film especially B&W negative film the adage was to expose for the shadows and develop for the highlights, meaning that you exposed the film to get good shadow detail but would control the zone where you would place the highlights in development. This is Ansel Adam's Zone System in a nut shell.

    While that worked great for negative film, it does not work great for digital sensors or slide film. The best way to expose for digital capture is to use the histogram and expose to the right meaning you want to expose so that the bulk of the data is a far right as possible without clipping.

    You can read more about shooting to the right here

    If you do that you will capture as much data as possible in a single expose and then use a RAW program to bring out that data.

    If you are going to use multiple exposure HDR the best way to do that is to blend 3 or more exposures that are equally exposed. If you are going to do a 3 shot blend you should do one "proper" shot, one under exposed from 1-3 stops, and one over exposed by the same amount. This is important because of the way HDR works (or more importantly the tone mapping function of HDR)

    Most people do not realize it, but HDR was invented for video games and computer animation not photography. That way you can create one digital model of an item and then easily shift the tone mapping to make it seem to be in various lighting situations. So the robot in the video game or Buzz Lightyear in the Toy Story Movies can move from shadows to daylight simply by shifting the tone mapping on the digital model. This is a much easier and more efficient way of doing animations.

    Anyway with the advent of Adobe CS2 this technology made it's way from Animation to still photography, and various other software has been written for it's use, but to work properly you need the under and over exposure to protect and render highlight and shadow detail.
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