RB67 and Simple Metering

Discussion in 'Medium Format' started by saltcod, May 9, 2007.

  1. Hi, I want just one thing for the least amount of money - a correctly exposed shot with my RB67.
    I have no idea what to do with metering. I have both a digital slr camera and a light meter (Sekonic L-328) but don't know what to do with either.
    Am I not Doing it Right?
    I was sitting home last night with my meter and my dslr and I'd meter the room, shoot the shot, and it would come out too dark.

    So, some questions:

    1. Do I need a spot meter?
    2. Is the Sekonic not a spot meter?
    3. is there a cheap spot meter?
    4. Do lenses affect metering? ie: my dslr lens is 24-85mm while my RB76 has a 127mm. If I meter a scene at 50mm on my dslr, will that be usable at all on my RB67? Thanks for ANY direction!

  2. 1. Do I need a spot meter?
    No. I meter about 98% of my pictures with an incident meter. It is just as accurate and much more fool-proof than a spot meter (which comes handy in very difficult lighting).

    2. Is the Sekonic not a spot meter?
    The Sekonic L-328 is an incident/ambient light meter. It has an optional 5° spot accessory.

    3. is there a cheap spot meter?
    Depends on your definition of "cheap".

    4. Do lenses affect metering?
    In my humble opinion, yes. I often open up ½ with some wide to 1 stop when using some tele lenses. But that's just me and my meter, others don't do this and get perfectly exposed pictures. Learn to interpret the result of your meter and how to correctly apply them to your specific gear.
    The most important factor with the RB67 is bellows compensation -- don't forget this!
  3. Terry,

    I know just enough about the use and feeding of a DSLR to qualify as a complete idiot but I do have a lot of experience with handheld incident meters and film cameras.

    When you say "I'd meter the room, shoot the shot, and it would come out too dark" are you using the DSLR to make the exposure or the RB?

    Is the 'film' speed set the same for both the meter and the DSLR?

    Is this speed the same as the film loaded in the RB?

    The incident meter is set up to read light falling on the dome and it doesn't matter to the meter if the subject is black velvet in the shade or a mirror in full sun. The meter in the DSLR is reading reflected light which will vary by color and texture of the subject.
    If you are metering a lot of light falling on a dark subject the incident meter will not compensate the way the DSLR meter would.

    When you meter with an incident meter the most useful tool is your feet - get as close to your subject as you can or hold the meter so that the light falls on the dome in roughly the same angle and intensity as your subject.

    Using a normal lens at a normal distance won't affect the exposure significantly but as you focus closer with an RB67 you have to take into account the bellows extension - I haven't handled an RB for years but I believe there is a scale on one side that shows exposure compensation.

    If you've been using the DSLR to check the meter my recomendation is to stop, put the DSLR away, load some film into the RB, and shoot away. Until you are fully comfortable with the meter and camera combo bracket each exposure up and down a stop or two (keep notes) until you find out what works. There are a lot of variables with film and processing and an old dog camera like the RB (a very useful old dog).

  4. I've had the same issues at first with my RZ. There should be a chart on the right side of the rail that extends your bellows. Depending on the lens and how far you are focusing, the chart will tell you how much to adjust the exposure.

    It's the same with large format cameras. When focused at infinity, there is no compensation. The closer you focus, the less light is hitting the film and you always need to compensate.
  5. I use the method you are using, with a digital camera, and it works fine. Just set the ASA of the digi the same as the RB67 film, zoom the lens to roughly the view angle of the RB lens (this depends on the size of your sensor, you didn't provide enough info about your DSLR for me to tell you what focal length would be equivalent to your RB67 127mm), meter the scene, transfer the settings to the RB, and shoot. Note that I don't do closeup or flash work, either of which would complicate this.

    You implied that you are trying this indoors. Maybe the dslr is cheating on the ISO due to the low light? I suggest trying it outdoors. Be sure to pick a dslr mode where it can't change the ISO.
  6. a much less expensive alternative is inside every box of film you buy....

  7. I recomend the film box approach also, subject to using neg materials with their tolerance to
    incorrect (over) exposure. Messing around with a DSLR as a substitute seperate meter just
    doesn't bear thinking about. Remember, the RB 67 in basic form weighs nearly 6 lb - then
    there's the tripod and all the other bits and pieces you'll inevitably get hold of. My choice
    is a lightweight pocektable meter (minolta flashmeter 4- ambient readings too) or the sunny
    16 rule.
  8. Even if you have a good meter, you still have to take into effect the bellows extention in the RB/RZs.
  9. unless your camera is routinely used for copy work or macro then you can forget about
    extension factors

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