Can I use a 35mm camera as a light meter for macro photography?

[Richard Raymond]

As the title says, is it possible for me to set up a 35mm camera (digital or film) with a macro lens so that I can use it as an exposure meter for large format exposure information? For example, I happen to have Nikon cameras. I have a 105mm Nikon macro lens. Can I set the lens at 1:1 and get an exposure reading that would be the same as 1:1 on the 4x5? There must be distance from the subject issues and other things. Any ideas on doing this?
Thanks
Ric

[Bob McCarthy]

Yes you can use a film camera meter (35mm) and transfer the settings to a large format camera, certain within the limits of leaf shutter accuracy. This works especially well with the spot meter function.

Having a meter which does scene evaluation and compensation may throw you off. That would be all digital and a few high end film cameras (my F5 for example). Maybe not so much with a film camera metering for color transparency.

The meter will compensate for lens extension at same reproduction ratios.

[Scott Davis]

In theory this will work, but I'd still opt for the hand-held meter because your subject-film plane distance will be different with a Nikon 105 Macro lens than it will be for the 150mm lens on your 4x5. Also, unless you really like swapping cameras on and off of tripods, you'll have a different field of view and angle of view with the 35mm camera, potentially altering what you're metering. Dragging around a second camera with its own lens seems like a lot of work to go to to avoid a little math - at 1:1, take the handheld meter reading and open it up two stops.

[Bob McCarthy]

reproduction ratio and it's effect on fstop adjustment to be applied is independent of format.

But there are a number of things that can go wrong if you don't uinderstand the approach.

If you can figure out lens extention and convert that to reproduction ratio. you're good to go especially if the 35mm lens has it engraved on the macro - some of the older lenses did that.

If you going to use a hand held meter, then you'll have to manually apply it to the meter reading by measuring the bellows at infinity and the in focus extension.

[Sirius Glass]

Yes, I have been using my Nikon F100 as a meter and a spot meter for my Hasselblads and 4x5s. Now I have a Gossen Luna PRO SBC so the F100 is now used as a camera and spot meter. But you have to remember to compensate for the bellows factor.

Steve

[Richard Raymond]

Bob, Scott and Steve,
Thanks for the information. I am planning on doing some setups with my 210 macro and this information will help a lot. At least I now have some means of checking my calculations to know if I have made a gross mistake in exposure.
Scott, I have a couple of meters I plan to use, mostly a good Minolta flash meter that has worked well for me for both ambient and flash on other projects. However, I am a little over cautious perhaps and like to check out things in as many ways as possible before I expose my 8x10 chromes. :)
Bob, thanks again for your help and advice. The part about 1:1 exposure being the same in any format was good for me to get. I think that if I check at 1:1 I will be able to get pretty close with 2:1.
Thanks again to all.
Best regards,
Ric