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  1. #1

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    Olympus OM2 automatic exposure and night shots

    Been wondering how the OM-2 automatic exposure handles low light metering -- whether the photog still has to analyze the scene and adjust the meter reading, or whether the OM-2 automatic metering handles it with no adjustment.

    I understand that the OM-2 automatic metering can keep the shutter open for up to 2 minutes. Let's say that the meter calculates 30 seconds at some aperture. There are two factors in play here that I think will make any automatic meter reading useless. First you have the meter using an averaging pattern off the film. This will take a dark scene with a few highlights and blow out the highlights because the meter will read the overall dark scene and try to create a middle grey picture. Second you have reciprocity impact if your film is subject to that phenomenon, and at that shutter time most films are subject.

    So for such scenes, the tendency to middle grey (meaning shutter open longer than appropriate), with a reciprocity factor that suggests longer shutter times -- do they cancel out in some way, to create a reasonable exposure of a dark scene.

    In my view, these two factors (especially reciprocity) make automatic exposure an inappropriate choice, and I would surmise that this kind of shot is best done with a hand-held spot meter, and reciprocity charts.

    But I see that other OM-2 owners rave about the accuracy of the low-light metering, and was just wondering if that applies to really dark scenes.

    Ultimately I'm sure I'll be testing this out, but wondered if the community of OM-2 users have any experience with such scenes and automatic exposures.

    Thanks,
    Xisbrat

  2. #2
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    I've used an OM-2n for night photography by moonlight and found early-on that the automatic metering isn't terrific for this. Automatic exposure can produce acceptable results by street light and my OM-2n seems to be able to manage exposures of 3 minutes plus. I did find my OM-4ti was much better for street light photography though. Spot metering from the reflected pool of light then compensating gave the best results. I also found that the shorter the focal length of lens used the less accurate the exposure becomes using in-camera metering. I assume that this is due to wide angle lenses collecting extraneous light due to the larger front element. For natural light I have found it is best to stick to manual mode and experiment with the film you intend to use. You can use your results to determine a table of exposures which work and most monochrome film has a wide latitude so it isn't that difficult to get some good images. You can use a standard table to determine exposure compensation due to reciprocity failure to get you started. One thing to note is the increase in grain at long exposures. Chromogenic films exhibit this less but I quite like the effect as I find it adds atmosphere. I once used Neopan 1600 which is quite grainy anyway and the results were "interesting".
    " ... a cook who relies on nothing but a sharp knife has no guarantee of producing excellent dishes." - Yoshihisa Maitani

  3. #3

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    Quote Originally Posted by xisbrat View Post
    In my view, these two factors (especially reciprocity) make automatic exposure an inappropriate choice, and I would surmise that this kind of shot is best done with a hand-held spot meter, and reciprocity charts.Thanks,
    Xisbrat
    Example of long exposures below using in camera averaging meter but not an OM-2 just to show what aperture priority automatic exposure can achieve using Fuji 100. Certainly learing the camera's metering characteristics as well as the films long exposure characteristics - under various lighting conditions, will help you achieve results that you can predict. In my case, I wanted to smooth out the rough sea and certainly didn't know what speed that would take. It was near dark when I took the approximately 10 minute exposure.

    The OTF metering of the OM-2 and OM-4 continuously monitors the scene to adjust for longer or shorter shutter times unlike most others that take the exposure reading at the time of shutter activation. Bummer they capped it at 2 minutes which is still better then the 30 seconds for Canon and even less for others.


    Larger version pic -> http://www.fototime.com/773634514E5AF6D/orig.jpg

  4. #4
    benjiboy's Avatar
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    You don't get many ten minute exposures with a set of batteries on an OM2
    Ben

  5. #5

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    Plain OM-2 exposure is not capped at 2 minutes. It is because of this that low light exposure with the plain OM-2 (not 2N) can be very creative. OM-2 will do night exposures as long as 19 minutes. I suggest setting your regular asa and then bracket on multiple exposures. Or for longer exposures, set a lower asa. BTW, these time exposures are read off-the-film (OTF), not off the curtain. The lower you set the asa on the OM-2, the longer your exposure capability. Set to asa 12, you get approx. 19 minutes, set to asa 1600, you get 19 SECONDS. John

  6. #6

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    Thanks!

    Thanks for all the detailed responses. The 2-min shutter limit was only for the OM-2n , but if the OM-2 gives 19minute exposures this intrigues and I may think about acquiring that camera.

    Your responses confirm my presumption, that autoexposure metering may be appropriate for low-light (but evenly lit) subjects, but not for unevenly-lit dark street scenes.

    Oh well, I was looking forward to experimenting anyways.

    Thanks!

  7. #7

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    John - Thanks for the identifying the metering difference between the plain OM-2 and OM-2N. I had not even considered that there would be such a difference within the model!

    Quote Originally Posted by xisbrat View Post
    Thanks for all the detailed responses. The 2-min shutter limit was only for the OM-2n , but if the OM-2 gives 19minute exposures this intrigues and I may think about acquiring that camera.

    Your responses confirm my presumption, that autoexposure metering may be appropriate for low-light (but evenly lit) subjects, but not for unevenly-lit dark street scenes.Thanks!
    You might consider the spot metering capable OM-2SP or OM-4 as the most accurate way to read a high contrast scene as you identified. As I am sure you are aware, in the scene you describe, you will sacrifice blown out highlight or shadow as there is no single capture media that will capture it all. You simply want to control the decision by auto exposure camera what the middle gray will be.

    But that is not to say a none spot metering camera cannot meter such a scene. This one was less then 2 minutes on Kodak Portra 400.



    In both of the examples I posted, not only did I need to rely on the in-camera meter, but I am sure I also took advantage of both film's generous latitude.



 

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