Handheld light meter

Andreas1 · 2010-03-22T09:48:59+00:00

Hallo Wolfram, hier mein Vergleich bei angemessener Graukarte, Kameras jeweils mit 1,4/50 und Entfernungseinstellung unendlich: Gossen Variosix F zeigt Bl...

Andreas1

Hello, I’ve noticed that my Gossen Profisix (which has just been back from the workshop for a service) always reads about 2/3 stops higher (spot metering) than my Nikon cameras (FM2, FE, F90). Could this be because the metering area or angle is so different? The difference can also be observed on a uniformly lit grey card. I’d be interested to hear about your experiences. Thanks Kind regards Andreas

Wolfram

Hello, I’ve noticed that my Gossen Profisix (which has just been back from the workshop for a service) always reads about 2/3 stops higher (spot metering) than my Nikon cameras (FM2, FE, F90). Could this be because the metering area or angle is so different? The difference can also be observed on a uniformly lit grey card. I’d be interested to hear about your experiences. Thanks Kind regards Andreas

Hello Andreas. This may be because the cameras measure TTL through the lens. The aperture values on the lenses are calculated values. They do not take into account the light loss through the lenses. But a difference of 2/3 stops is quite significant. It has nothing to do with the metering angle itself. If you’re measuring against a uniformly lit surface, such as a grey card or a building wall, it doesn’t matter whether you use a wide angle or a spot meter. The lighting is the same, after all. Even if you’re using a 28mm or a 400mm lens.

Wolfgg

Hello Wolfram, Here is my comparison using a standard grey card, with both cameras set to a 1.4/50 lens and the focus set to infinity: Gossen Variosix F shows an aperture of f/11.1 Canon A1 Camera 1 shows an aperture of f/11 Canon A1 Camera 2 shows f/11 Contax 139 stubbornly shows f/8.11 And another discovery (though nothing new with selenium cells): A Gossen Sixtino2 with a selenium cell, bought in 1982, now only shows f/2.8–4, so it’s completely shot. Regards, Wolfgang

Wolfram

Hi Wolfgang. It’s all fine. With the Contax, the optics can of course play a part. But it’s ‘only’ half a stop anyway. Besides, what’s the point of …,1? That’s why I have my analogue LUNASIX F. I don’t want to know that precisely. I can only set the aperture on my lenses in half-stop increments anyway. The Belica displays to a quarter of a stop. No film is that precise these days. Sure, the selenium cells age. You can readjust them, but then the question is whether it still measures linearly. (?) But I know what you’re getting at: the difference between the actual and calculated aperture. With your Canons, that’s practically zero, of course. It can vary from brand to brand. @ Andreas: If your Beli was in for repair, you’re covered by the warranty.... . You’ve already paid for the solution to your problem. Why are you worrying about it? Regards Wolfram

Wolfgg

Hello Wolfram! The additional display of tenths of a stop may look a bit excessive, but it does make sense with digital displays because it allows you to round off (up or down) in your head, so you can immediately see which way it makes sense to round depending on the subject. Incidentally, this isn’t just ‘empty’ precision; one-tenth of a stop is approximately 7% of the measured value (2 to the power of 0.1) and can be easily achieved electronically in conjunction with the built-in linearisation table. Of course, emulsions have far greater tolerances than 0.1 stops (even good transparency films up to +/-0.3 stops), but when testing emulsions, the zone meter user is glad to have at least a very stable and accurate reference point available. The Contax also shows a slight downward deviation with other lenses. Regards, Wolfgang

sputnik

Hello, I’ve noticed that my Gossen Profisix (which has just been back from the workshop for a service) always reads about 2/3 stops higher (spot metering) than my Nikon cameras (FM2, FE, F90). Could this be because the metering area or angle is so different? The difference is also noticeable on a uniformly lit grey card. I’d appreciate hearing about your experiences. Thanks Kind regards Andreas

When I had my Profisix in for repair, it came back with a measurement report showing that the deviation from the target exposure value for light values above 1 (at 15 DIN) was consistently less than 1/10 stop. For light values below 1, it was just +1/10 stop. Comparisons with a new Digisix and the in-camera EV values of a Nikon F100 and a Rolleiflex 6003 showed 100% agreement. I once read somewhere that Gossen calibrates to 12% grey (or something like that) and Nikon to the standard 18% grey. Based on my own comparison, I consider that to be nonsense. By the way, you don’t need a grey card to compare your Belis. Just use a LARGE, single-coloured and uniformly lit surface. Then you won’t need to worry about differing measurement circles either. Best regards, Siegfried

Wolfgg

But the large solid-colour area shouldn’t be too colourful, otherwise the different spectral weightings of the Belis could skew the comparison; grey or white would be the safest option. Regards, Wolfgang

sputnik

Come on, let’s not get carried away :-) It’s not quite that crucial. Besides, I don’t think there’s much difference in the spectral sensitivity of these things. I only mentioned the deviation of less than 1/10 stop in the measurement report because I wanted to point out that a deviation of 2/3 stops AFTER A SERVICE isn’t normal. The maximum measurement tolerance for new/serviced devices is 1/3 stop. Was the unit really at GOSSEN in Nuremberg? They’re usually pretty on the ball. Best regards, S. PS: If the unit had been tested, I reckon you’d have received a measurement report as well.

Andreas1

Come on, let’s not get carried away :-) It’s not quite that crucial. Besides, I don’t think there’s a huge difference in the spectral sensitivity of these things. I only mentioned the deviation of less than 1/10 of a stop in the measurement report because I wanted to point out that a deviation of 2/3 of a stop AFTER A SERVICE isn’t normal. The maximum measurement tolerance for new or serviced devices is 1/3 stop. Was the unit really at GOSSEN in Nuremberg? They’re actually quite competent. Best regards, S. PS: If the unit had been checked, I reckon you would surely have received a measurement report as well.

Hello, thanks for the replies. No, the part wasn’t at Gossen and unfortunately I didn’t receive a measurement report. Is the service at Gossen good? What costs should I expect? Thanks Andreas

sputnik

No, the part wasn’t at Gossen and, unfortunately, I didn’t receive a repair report. Is the service at Gossen any good? What sort of costs should I expect? The staff at Gossen are very knowledgeable, helpful and accommodating. I’ve only just realised that again. As for the expected costs, I can’t give you any exact figures anymore. If I remember correctly, it was pretty much exactly 100