Light meter of Leica M6

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I think I have a quite peculiar problem with my M6 lightmeter: the problem is the following: as you know, light is measured through a complicated meter system, whose main "instrument" is the small round white circle in the middle of the curtain. Some months ago I noticed that the metering with the camera would give an exposition about 1 stop higher than the metering with a Lunasix lightmeter, i.e., light measured with the camera would give 125/f11 and with Lunasix 125/f8, in exactly the same conditions, needless to say. Is it possible that the problem comes from a slight loss of brilliance and "whiteness" I noticed in that central white circle? Any tips welcomed. Thanx. Nuno

-- Nuno Fontes Nunes (Nuno.Fontes_Nunes@curia.eu.int), October 24, 2000

Answers

Numo,

I have seen what I thought to be variation between my M6 and my Sekonic incident meter... especially when I had my 90mm lens attached. When I felt a bit of fear, I would look for a constant tone and check again. Usually this would make the difference go away or at least get so close as to be no big deal.

This gets to the relative difference in accuracy between an incident meter versus a reflective meter. Additionally, the M6's meter gets pretty tight when you use longer lenses, so the inaccuracy in aiming can be greater, assuming some possible parallax error. If I fill the frame with an 18% gray card, all of my lenses register the same, but it a real world shot, there is often quite a bit of variation. I have learned to do a surrogate exposure measuring... say, from grass, which is about 18% gray.

All of the M6's I have, and the ones I have seen have seen have some non-uniformity to the white circle on the shutter. I might think this is built in, since the metering eye is actually off-center.

-- Al Smith (smith58@msn.com), October 24, 2000.


Thanks a lot for your answer. At least I have now a logical explanation, and I'm much more relax about my material: my M6 didn't turn crazy... It only suffers from a kind of family problem. After all, such a "perfect" camera should have some "bug" to really be ... perfect!

-- Nuno Fontes Nunes (Nuno.Fontes_Nunes@curia.eu.int), October 24, 2000.

Nuno,

But how are your pictures turning out? I found over the years that the various metering patterns (spot, incident, reflected, matrix, etc.) in my cameras/meters usually seem to disagree. Once I got the hang of precisely what the M6 was metering, my exposures improved dramatically and consistently. You could drive yourself crazy doing such comparisons.

Good luck, Sergio.

-- Sergio Ortega (s.ortega@worldnet.att.net), October 24, 2000.


I went through the same kind of worries. In fact after mesuring light with my M6 on a grey card, I was able to match exposures between my hand-held meter and my M6. If you want to go through this kind of game, you have to be very careful about the way you position the grey card and the way you aim at it with your M6.

I read somewhere that the paint used for the white spot in M6 is based on some oxyde which is supposed to stay stable for several decades...

-- Xavier Colmant (xcolmant@powerir.com), October 24, 2000.


When my girlfriend decided to buy herself an M6, I decided to compare her meter with the one in my M6 (Mine is 96, her is 98). The results is one stop difference. Both camera on the same tripod (one at the time with a quick release plate so, exact position) facing a white wall in my appartement, using the same lens. I use a hand held light meter as reference (Minolta IV with 5 degres spot). Mine is underexposing one full stop (Both camera and Hand held meter at 200 asa rating). Both camera are close to mint condition and the white circle on the shutter appear identical so, the only logical conclusion would be factory ad

-- Eric Laurence (edgar1976@hotmail.com), October 24, 2000.


Virtually no light meter will give an identical reading to another. Never trust a meter you have not used extensively as they all vary. It is the same as the watch story where a person with one watch knows what time it is while a person with two watches does not. Use slide film and get familier with what your meter does.

I use to obsess about this sort of thing and believed whatever I read rather than my results. I read that Nikons set their meters to overexpose by one stop so I tested it. I checked my F3 with a 105/2.5 carefully against my handheld meter with the lens racked out and pointed at a grey card. Sure enough it was off by a stop!! Stop......think....where did I make my mistake? I had the lens at closest focus. Which reduces the light reaching the film by....you guessed it.....almost one stop.

I shot properly exposed slides before resetting my meter and properly exposed slides after I reset my meter. I subconciously altered my technique to compensate for my meter. Which meter was correct. Was the grey card faded? Who cares. Learn YOUR meter, toss all those extra meters, and away you go!

Cheers

-- John Collier (jbcollier@home.com), October 24, 2000.


Note that if the if there were any loss of whiteness (refectivity) in the white spot, you would have to open the lens wider (say, to 5.6) compared to the Gossen's f/8 reading, to indicate "correct' exposure on the Leica. But you were stopped down to 11. Thus this is not the explanation. I suggest bracketing in 1/3 stop increments by changing the film speed dial one notch at a time on successive exposures on slide film. When you get the slides back, note how many 1/3 stops your best exposure differs from the published film speed. Then use this as the basis for customizing your film speed settings on sunsequent rolls. So for example, if you shoot Fuji Provia 100 and your best exposure was with the film speed set to 64, then you would make a practice of setting the speed dial always 2 clicks lower than the published rating of whatever film you are currently using. You might fine-tune this adjustment based on results with subsequent rolls, under varying conditions. Or else, send it in for adjustment-- but you still might have to put in some compensation.

-- Bob Fleischman (RFXMAIL@juno.com), November 02, 2000.

The M6 meter gives the best results of any reflected light meter I've used so far. Admittedly I haven't ever used an F5, which must be great. The large spot enables you to unselect inappropriate zines while covering a large enough area to average a good mid grey. I shoot only slide and get outstanding results with the M6, often in very difficult lighting conditions.

As for agreeing with handheld meters, I have a Sekonic something or other, but after a year or so of using the M6 meter I never get the other one out.

The extremely useable meter combined with first class lenses - that's why I use the M6, and also why I can't understand the nostalgia for older M cameras.

Of course it's possible you really do have a meter calibration problem, but nowadays I'd trust the M6 meter. Try checking against a grey card; if you get the same results there your problem is simply knowing how to use the M meter. You don't say whether your results are off with the camera meter. If they're not, then trust it.

-- Robert Appleby (laintal@tin.it), December 03, 2000.


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