Metering at night

Discussion in 'Medium Format' started by woolly|1, Aug 19, 2010.

  1. Well, I've taken the plunge with medium format and bought myself a very minty Pentax 67 body/wooden grip and metering prism plus the 45/f4, 75AL, 105/f2.8, 165LS & 200/f4 lenses. Even got the unused three extension tube set thrown in for $750! My bargain of the year I'd say. Came from a guy who was going all over to digi. So far so good.
    Now before I go wasting a ton of money on bad shots I intend to shoot night scenes both urban and industrial and wondering about metering. Should I trust the prism meter, add say two stops or try my Sekonic L-358 incident meter reading (assuming similar light on the subject and my position) facing towards camera.
    Let's take a specific example :- shoot across a river to a refinery (trying not to get arrested in the process), ok a stadium instead! Light comes from complex plus reflected off river plus last rays of sun below horizon. Now if I was using the D300 I'd fire off a 5 sec shot and chimp, but I want to try and 'go it alone' on this one. Probably err on the side of longer exposure for water smoothing effect.
    Any helpful tips are gratefully received.
  2. One method would be to use your D300 as your test shot, and take that exposure as the preview for your film shot. I do this occasionally if I don't have my spot meter with me. But I would rather have a spot meter. Using the zone system (worth boning up on, or at least having a chart with you of the zone values), you can meter for a highlight area (I like zone VII where you start to get detail in a highlight area), then two stops down would be your correct exposure for zone V (neutral gray). That would be my preferred method. Of course you need to know if the film you are using has any reciprocity effects, and have that info handy.
  3. There are caluclators out there for this type of application. One is called "BlackCat". I think that has to be bought. There is another that is on the internet, but I can't recall its name right now. Something like "Parker" comes to mind.
    You do know about reciprocity, right? Whatever your digital camera or Sekonic indicates probably won't account for that. Reciprocity is discussed on the data sheet for whatever film you'll be using.
  4. @ Michael
    I thought of that but the Nikon is a bit large as a light meter. I have the Sekonic already so want to ride bareback with that for a while. :)
    It's beginning to sound already that a spot meter is called for. If developing a technique with the Sekonic L358 doesn't work I'll have to carry the d300 and set it for spot metering. Clumsy though.
    @ Brian
    Yes I'm aware of recip failure but researching the Kodak Portra on their site (camera is loaded with that for now but will start using my Velia 50 soon after) they claim no Recip failure allowance needed up to 10 secs ... no mention of beyond that though.
  5. Metering at night is where a spot meter and the Zone System really shine. I have a Pentax Spotmeter V that I have had for 30 years and it has never failed me.
    In-camera meters can be pretty much worthless, because of the potentially very large range of exposure values. They can very very easily fooled. Meter the lowest areas in which you want to record detail and expose this for Zone III. This is two stops below the Zone V (graycard) setting. Then start metering around the scene to see where the other values fall. The highest zone where you will record detail is aroudn Zone VIII.
    As previously mentioned, be mindful of reciprocity with long exposures. This usually does not come into play unless your exposures are around a minute or more, but every film is different.
  6. Clive,
    "Fred Parker Ultimate Exposure Guide" is what I was thinking about. Google & find. Might be useful.
  7. Hi Clive,
    Using a Digital as a benchmark to work from is OK. You will gradually get a feel for how long you need to expose your film for, I would always suggest that you stick to 400asa ( Fuji ). In low light situations 5 seconds either way is not dramatic even with 400asa, I photographed the Major Oak in Moonlight with 400asa Fuji Pro and a f1.2 lens at full aperture, takes 30 seconds, but you could settle for 20 seconds but just not so bright. The 30 second exposure resembled daylight, so it's not that critical like working with daylight.
  8. This site provides lots of resources to get going on night photography both film and digital:
    I've had the best results so far by using a small digital camera to approximate low light exposures. And I do mean approximate, because I haven't found exact correlations. My Pentax digital spotmeter has not proven to be of much use to me after twilight.
    For black and white, I've used Acros 100 because it has very little if any reciprocity effect. But, an exposure that works on a digital camera for, say, ISO 100, f8, 5 seconds may not work in film if a high contrast situation, as in a mixed-lighting street scene. I'm finding that this film may require twice the exposure time as my digital camera for comparable settings.
    That film is very fine grain, which may not be the look you want. Maybe a very high speed film will work better for you.
    With film, you may need to expose for the shadows, and to avoid losing detail in the highlights, especially urban situations, shorten the film development time or have your lab do that for you. Another method might be to use a compensating developer, such as Diafine, if you do it yourself.
    A wide aperture will provide very little depth of field, so exposure times will have more effect on one film vs. another in order to offer more flexibility in that department.
    No matter what, making records and keeping track of them is very important. A digital camera can also have a recording function so you needn't carry an extra light to see what you're writing.
  9. Fred Parker's guide works. Find it here.

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