lightmeter discrepancies Seconic 508 vs Minolta

[zippy]

I rented a Seconic 508 to check against my Minoltal IVF lightmeter this weekend and was surprised by the results. I knew there would be some differences between them but what I found was the that the Seconic reads for less exposure. The oddness is this: the Seconic meter gives about a -2/3f reading in bright sun, compared to the minolta measuring the identical subject but only there is only a -.2f difference when metering in say an interior, much darker area. The meters are different but not in a linear way and I suspect the problem is with my Minolta meter. Anyone know what gives??

[David R Munson]

Are you using the 508 on spot? I've heard from several sources now that Sekonic spots are calibrated to a 13% gray instead of 18% (that was it, wasn't it Bill?). Anyway, that might be the reason(?)

[KenM]

I wouldn't worry too much about the discrepancy. I did exactly the same test wh en I received my Spotmeter F via eBay. I took it to the camera store (called, s trangely enough, The Camera Store), and did a comparison against a Sekonic - it could've even been a 508. The results were rather disquieting - there was a sto p difference, but I can't remember which way - doesn't matter, really - the read ings were off by a mile.

However, when we compared two Minolta spot meters, the exposure readings were al most identical.

I'd try the comparison again, but do it brand-to-brand. I've heard that Sekonic meters give quite different results. Guess that's the main reason to do basic testing to determine your effective film speed with your lens/film/meter/develop er combination.

HTH.

-klm.

[Jim Galli]

Curious why the Minolta is automatically suspect? The answer you don't want to hear is it really doesn't matter. After you use the Minolta or the Sekonic for a while you'll start automatically compensating for it's idiosyncracies. (sic?) I love my spotmeter F. I'm guilty after 3 years of using it of knowing how it's thinking and ...tweaking. What really screws you up is when you put new batteries in and have to start the process over again!!

[Michael Kadillak]

Not to be cynical with this subject but the only non-variable in this equation should be the intensity of the measured light. With a side by side comparison of an incident or a spot meter the readings SHOULD be very close if the meters were properly calibrated. Unfortunately, manufacturing decisions relative to how they decide to present this data leaves much to be desired. Small variances should not be a problem in the film testing as long as the error is linear.

I have seem folks spent thousands of dollars a year on lenses and film and scoff at a simple $40 charge a year to get their meter calibrated. And then they wonder why their results are inconsistent?

Bottom line is - who is to say that any meter (yours or the rented one) are accurate? As a result, I see no reason to spend money on any rented meter when yours could have been sent to any number of quality shops and come back to you dead on. Get to know your meter calibration man or woman on a first name basis. Their importance to your photography is not given the credibility it should IMHO.

Good Luck

[Richard Stum / Kinesis]

My guess is that the Minolta is right on and the Sekonic is off (uderexposing). Read this page on my site (Kinesis) for a write-up I did on this topic.

[Richard Stum / Kinesis]

Opps, I put the wrong URL on my previous post. I meant to post this page.

[John Hicks]

Meters aren't necessarily calibrated to the same standard and of course might no t retain their calibration over a period of use.

I can't think of any good reason to believe that a rental Sekonic is better-ca librated than a Minolta or vice-versa.

I'ts mighty easy to calibrate an incident-light meter (provide you're not in t he far north or south); your standard is the sun, and the meter should read 1/EI @f16. Twiddle the adjusting screw until it does so.

Meters will also vary in linearity; that's just the nature of the beasts. With modern meters the error usually isn't huge, while some older meters could be wi ldly non-linear.

[Bob Ashford]

Hi Everyone, This is just so funny (strange not Ha Ha), I friend and I working in two different institutions have just been talking about a variation of this same problem. Our Minoltas and Sekonics are exactly the same in Contiuous Mode (thats two Mins & two Seks) but the both Sekonics are one stop under in FLASH MODE. Interesting

Regards Bob Ashford

[David F. Stein]

Yes, send it to Mr. Milton at Quality Light Metric and I am sure the charge will be a worthwhile expenditure. I have a Minolta Autometer IIIF and Sekonic Studio Deluxe. In incident mode, the two meters do and have always been right on. BTW: the other day was a Sunny 16 minus 1: set the Sekonic to ASA 125, guess what the meter called for at 1/125-Yup-f/11. At sea-level North America, exposures aren't really that difficul