OM-4 multi-spot metering questions

Discussion in '35mm Cameras and Accessories' started by olwick, Feb 24, 2011.

  1. olwick

    olwick Member

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    I've read the manual and brochure about the OM-4 multi-spot metering but I'm still confused (I haven't bought one yet - I'm still trying to determine if it's for me)

    Let's say I have a scene with strong highlights and shadows. If I meter on the highlight and hit the highlight spot button, then go to the deep shadows and put a shadow spot on there, how does it retain the exposure for both properly? Isn't it just going to average things out and have everything gray?

    Apologies in advance for being dense.

    Mark
     
  2. mopar_guy

    mopar_guy Subscriber

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    OM-4T Spot metering: How I use it

    Keep in mind what the in camera metering is doing. In the center weighted averaging metering, the camera will give you a reading for a brightness value for a middle gray. If you take a Spot metered value, the metered value is the correct exposure to render as a middle gray.

    Lets say that we take a spot meter reading of someone's face. That spot reading will generally give correct exposure for a portrait. What if we take a spot reading of a white object. In this case, the suggested reading will try to render the "white" value as a middle gray, and the shot turns out underexposed. Pressing the "Hi. Light" button shifts the metered value to give two more stops exposure and the white object is rendered correctly as a white.:cool:

    Here's another example: We take a spot meter reading of a very dark object. The spot reading is the suggested exposure to render the dark object as a middle gray. The camera doesn't really know the difference between light colored objects and dark colored objects, it is just reading the amount of reflected light. So for our spot metered reading of the dark object, we can press the "Shadow" button and the spot metered reading is shifted to give 2 2/3 less exposure and the dark object is render correctly on the film.

    I just looked at the manual. There is no reference to use the "Hi. Light" and "Shadow" features at the same time. Just use one or the other. What I generally do is to set the camera to manual exposure mode so that I have to set the aperture and shutter speed. I take a spot reading of a light colored object and then I take a spot reading of a dark object. Both readings show up as dots in the viewfinder, but the suggested "average" value is also shown. This is all the information needed to decide on an exposure. It is a little like having a miniature Zone System in the view finder.:cool:
     
  3. Rick A

    Rick A Subscriber

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    IIRC, if you want more highlite bias than shadow,then click on the spot button twice in the bright area and once in the shadow area. That will give you a 2:1 ratio for highlite. You can take several spot readings and the camera will average them. If you use the hilite button, then the shadow button, it will cancel the hilite.
     
  4. olwick

    olwick Member

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    Thanks guys. Page 79 of the manual was what I was referring to. Rick mentioned it where you can click the hilight or shadow multiple times to add "weight" to that area (ratio). I think it just averages according to that page.
     
  5. Les Sarile

    Les Sarile Member

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    These two facilities are completely separate functions. For instance in Auto mode, when you press Spot, then pressing Hi Light will overexpose the spot initially metered by 2 stops. When you press Spot, then pressing Shadow will underexpose the spot metered by 2 2/3 stops. Pressing both will not average the two as in multi spot mode. If you press Hi Light first then Shadow second, then the Shadow will be active. If you press Shadow first and and Hi Light next then you're in Hi Light.

    When you press Spot, then that's automatically the first spot metered. Pointing to another scene and pressing Spot again will average first and second and so on.

    The OM-4 is the most sophisticated spot meter capable manual focus camera. It's meter range is only second to the Pentax LX but of course the LX does not have spot metering. Both are the best aperture priority auto expose cameras particularly for very long exposures even by today's latest and greatest.
     
  6. Rick A

    Rick A Subscriber

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    Maybe this will help more. If you switch the selector to auto, then take a spot reading of something white. To render it white you then press the hilite bias button , the camera will automatically add two and two-thirds stops more exposure. By just taking a spot reading then making the exposure, will render the area metered as middle gray. If you desire a black area to be black in the print, take a spot reading of the darkest area and then press shadow button. The camera will then subtract two and two-thirds stops of exposure. If you take a spot reading of the darkest area and made the exposure, that area will be rendered as middle gray.