M6 light meter in artificial light

[Assaf]

Hi friends,
I got the feeling today that the light meter on my M6 underestimated the light by at least one stop.

I measured the light in a church. It was lit by tungestan bulbs which were hung about 3 meters high. The light looked to me (from my experience) much stronger than the camera told me. Another photographer there took pictures with a Nikon D80 with a measurement 3 stops higher, and slightly underexposed the shadows.

When I came home I verified that the light meter was OK: with respect to measurements I know by heart, and with respect to another cameara. It was precise.

There's a good chance that the light was too contrasty and that I didn't make the right judgement while taking the measurment.

I just want to make sure that it's my mistake and not an unknown feature in the camera - that it's sensitivity to light depends on the color temperature, and the nature of the light.

I shot Neopan 1600 and I'm currently in a dilemma wheter to pull it in the process or not.
I can give more details on the scene if needed. Any help would be appreciated

Assaf

 

[rpsawin]

Assaf,

The M6's internal meter measures reflected light and renders the reading as medium gray. For average situations where there is an even distribution of light values this works fine. You must use your meter reading as a guide and adjust your exposure for lighting that is not average....ie snow, beach, shadows and such.

The handheld meter normally measures incident light or the light falling upon an object with no adjustment for color, shape or texture. The fact that the reflected light reading and incident light reading did not match is not a surprise. I always carry a Kodak grey card with me and can get reflected and incident readings to match within a half stop. As to the digital reading the camera is balanced more toward producing exposures for slide film than b&w negative film. Generally, you meter for the highlights with slide film as opposed to shadows with b&w.

In any case Neopan 1600 has a fairly wide exposure latitude and a stop should not be a big deal. I would process as normal and correct during printing. I hope this helps.

Happy Holidays,

Bob

 

[Assaf]

Thanks Bob,
actually I'm afraid that I was wrong in more than two stops.
The exposure was f2 to 1/30 sec for ISO 1600. I measured on gray surfaces (I think I learned which gray it is) and also measured on the palm of my hand and added one stop. The measurements matched.

I know that f2 for 1/30 on ISO 400 is something like the light I have at home, and I think it was roughly the light there.
Anyway, thinking of it, overexposure would burn the highlights (which isn't a big deal) and pulling the film might only restrain the contrast (also not a big deal).
Well, I'm still thinking...

 

[ferider]

Two notes, Assaf:

1)

f2 to 1/30 sec for ISO 1600.

This is not far off the limits of the camera's sensitivity with old meter circuit.
If you have a classic M6 you might think of "upgrading" the electronics which
will add around two stops, in my experience. Also, make sure you use a good
battery.

2) Even though one assumes that all meters meter the same, I observe differences
among others depending on color temperature. For example, my Gossens (a Lunasix
and a digital), in Tungsten light, give me one more EV than my Calculights (two, they
both produce identical results).

In the end you have to get to know your meter and correct.

Roland.

 

[Assaf]

Thanks ferider,
since the measurements is so low, I think it's an underestimate.
Do you know how much should the meter upgrad should cost?
I think I'll eventually use a handheld incident light meter. I feel comfortable using it and it clears out most of the doubts

 

[ferider]

Assaf,

I forgot the exact amount, but Don did the upgrade for me as part of a full
CLA for less than US 200.

But nothing against hand-held metering, of course ... Beats any in-camera
meter; easier to measure the scene's dynamic range, incident, etc.

I use the in-camera meter mostly for casual portraits.

Best,

Roland.

 

[JNewell]

There's a good chance that the light was too contrasty and that I didn't make the right judgement while taking the measurment.

Quite possible - but...

This is not far off the limits of the camera's sensitivity with old meter circuit.
If you have a classic M6 you might think of "upgrading" the electronics which
will add around two stops, in my experience. Also, make sure you use a good
battery.

This might also be your problem. I am pretty sure that the Leica literature puts the difference at 1EV, but there is a difference. In terms of cost, one of my M6es is a second batch body and the meter circuit went Tango Uniform a year ago. The cost was around $200 for parts and labor from DAG, if I recall correctly, though I had it done as an add-on to a CLA.

You didn't indicate your serial no. or year of production? It's possible you have the later circuit. I believe that the test is whether the LED arrows go dark when there's insufficient light (original) or whether they blink (Mk II circuit).

 

[Assaf]

Quite possible - but...
You didn't indicate your serial no. or year of production? It's possible you have the later circuit. I believe that the test is whether the LED arrows go dark when there's insufficient light (original) or whether they blink (Mk II circuit).

Serial number 1658094. I was told by the previous owner that it's an early model, possibly manufactured in 1985 (was he right?). The camera has recently undergone a massive CLA by Don, including VF upgarde.

The LED blinks.

BTW, is the upgraded meter identical to the one in the M6TTL?

I've just dropped the film in the lab (it's past midnight here). I can still tell them to pull it, and I've a good feeling I did overexpose.
Should I tell them to? Should I toss a coin 😕

Thank you all for the kind help. I'll post pics from this film, if anything worthwhile comes out...

 

[Assaf]

Results and conclusions

Results and conclusions

well, I processed the film to 1600.

The exposure seem OK, to my eye, and to the lab's eye.

Scanning it, I think that taking a stop less wouldn't have hurt noone, but the negative is fine as it is.
Here's one example - midnight mass in Abu Gosh (Jerusalem mountains), day before yesterday

the picture was moved to W/NW forum

 

[Ken Ford]

A wonderful photo, Assaf.

 

[Assaf]

A wonderful photo, Assaf.

Thank you, Ken

Can you please remind me where's the place in RFF to post pictures (of photographic not gear/technical interest)?

I have a few more from the same session

 

[Ken Ford]

I would say the Gallery is best! http://www.rangefinderforum.com/photopost/index.php

 

[Assaf]

Put the picture and three others in my personal gallery. Is there a specifically popular gallery there?

I'd be happy if you had a look

(I should put a link in my signature)