Light meter

[kamboura]

Hi, I have a question regarding built in light meters. I am currently shooting film, using a very old Mamiya NC SLR camera, and a newish Canon A2 EOS. When comparing the light meter reading from both cameras for the same scene, same focal lenght, even when I set my EOS to center Weighted to match the Mamiya, I still get a considerable difference between the two (up to 2 f-stops). However, both pictures come out fine... is it because of the correction that the lab does, or is it possible to have 2 "correct" light readings based on the camera.

Thanks All.

[another view]

First off, it will depend on the scene you're metering. The Mamiya most likely has a center-weighted meter and the Canon probably has a Matrix or evaluative meter, which is usually (not always) more accurate. So if the scene is soft light and not a lot of blacks and/or whites, then they should both be pretty close. Center weighted can more easily be fooled by contrasty light or a lot of light or dark colors though.

Some cameras have both types of metering patterns, and also add a spot meter. Mine has all three and I use one or the other depending on the situation - one isn't always best. Also, two identical cameras with identical lenses metering the same scene with the same metering pattern can have a difference - the key is to learn how your meter works and take that in to account when shooting.

Color negative film won't help you with this, though. Shoot some slide film and you'll see a big difference - you can see the difference in 1/3 stop exposure.

[Asylum Steve]

Steve is absolutely right with his explanation of why your meters might give different readings, but I also think in this case, the reason YOU give may be true: even if the negs from the two cameras are off by a stop or more, a machine processed print will most likely be compensated to the correct tones and the two prints may look the same.

The best way to judge the difference in the cameras is to look at the density of the negatives. Or better yet, a contact proof sheet that was exposed for minimum black for each.

While in general, there is usually ONE optimum exposure for a given scene, what you've learned is that film has LATITUDE, meaning you can vary from that exposure, sometimes by several stops, and still have negatives usable enough to give you a decent print...

[kamboura]

Thanks all for the reply.

Just a quick clarification. I have set the Canon to Centre Weighted to match the Mamiya, and I still get different result. Should I simply assume that one of them is wrong? Since there can only be one right reading?

[another view]

Should I simply assume that one of them is wrong?

Probably, but which one? Maybe they're both wrong - it's very possible. Take a half a dozen brand new cameras and set them up the same way - the difference between them could be as much as a stop. Chances are when you bought one that you didn't check out five more to see how yours stacks up. Best way is to get used to that camera's meter, and compensate for it. You've got to use slide film to do this, neg film has too much latitude and unknown corrections are made when printing.

Here's how Galen Rowell did it (at least close):

Load a roll of your favorite slide film. Set the ISO to whatever the film is rated for. Compose and meter a shot, but shoot it with compensation of -1, -2/3, -1/3, 0, +1/3, +2/3 and +1. Do this for five shots, total of 35 exposures but pick different types of scenes - like bright and sunny, in the shade etc.

When the slides come back, spread out the seven of the first scene and pick the one that looks most correctly exposed. Do that for the remaining five shots. Probably most of the shots you pick will be the 0 compensation or the +1/3, or whatever it is. This will tell you how your camera, with that film, meters versus what you want to get. If you pick mostly +1/3 shots, then your camera underexposes by 1/3 stop. If you pick mostly -1 shots, then your meter overexposes by one stop, and you know to compensate for it.

[kamboura]

great, I will try that... Thanks.