Light Meter Question

[Sean Galbraith]

I have a Minolta Autometer III light meter. It does not appear to have shutter speeds and some apertures that line up with the old shutters I have on my 2 lenses for my Crown Graphic. For example, 1/100th of a second on the shutter vs. 1/125 of the meter or f4.7 on the shutter vs. f4 or f5.6 on the light meter. Any recommendations for not too expensive (sub $200 used) that might better match what gear I have (and can calculate exposure times of up to, say, 30 minutes)?

[Aahx]

I just looked at the Seconic L-758DR I have here at work and it will go to 30 min exposures though that will not count for reciprocity adjustments of the film you are using. It also shows your Fstop in 1/10th of stop increments so you can get a tighter reading. I believe my L358 incedent meter does all this as well but I don't have it here with me to check. Your 1/100th would be essentialy a third of a stop less than 1/125th. Though there may be some slight variance on those older shutters, as I know my old compur shutter has.

[Jon Shiu]

I think you should just guestimate, as the shutter speeds are pretty close and probably not exactly accurate as marked.

Jon

[Sean Galbraith]

Even when shooting slide film?

[Jon Shiu]

I mispoke. You should make an intelligent adjustment for the slight difference in 1/100 vs 1/125. Or f4 vs f4.7. Also, on an older shutter the speeds may be off and you should have a printout of the actual measured shutter speeds and how many stops off they are. I use a digital pentax spotmeter, which actually may be easier to use, because it has an analog dial to calculate the exposures.

Jon

[Doremus Scudder]

At the risk of seeming excessively nerdy, here, in .pdf-file form, are shutter speeds and f-stops in 1/3-stop intervals for your exposure calculating pleasure.

FWIW, I calculate to the nearest 1/3-stop even with black-and-white. I have my shutters tested, and where note where they deviate from the standard speeds. These deviations go on a sticker on the lensboard and are figured in when calculating exposure.

However, I haven't memorized the tables nor do I use the in-between numbers much (except for the few that correspond to shutter speeds on older lenses such as 1/100, etc.). What I do is think in terms of "plus" or "minus" a third-stop exposure. In this case, 1/100 sec can just be thought of as 1/125+. In-between apertures can be thought of this way as well. This system works well with meters that have 1/3-stop hash marks between the full stops. It happens often that I have an exposure in my log something like, "1/125+ at f/32-."

Best and happy exposure calculations.

Doremus Scudder

[Kevin Thomas]

On the monolta III next to the large F-stop figure is a smaller one place decimal figure that reads the exposure in 1/10 stops that should allow you to fine tune your settings.

If you haven't got the manual you can download it at
http://www.butkus.org/chinon/minolta/minolta_autometer_iii/minolta_autometer_iii.htm