'M' film speed dial

[maddoc]

It works 100% if your grey-card is roughly of the same size as your subject (for example a portrait) and lit by the same light at the same angle....

Just a few words: that kind of reading (reflected) only works sometimes...

The light you read that way, depends of the kind and harshness of that light, and also on the angle of incidence on the card or skin. Payasam is right about it works sometimes, and Roger is right about it doesn't work sometimes.

Cheers,

Juan

 

[payasam]

Juan, perhaps you will tell me why two people who say seemingly different things are both right at different times. I add "seemingly" because it is by no means clear what Roger Hicks wanted to say.

It is of course tautological to hold that because something works only sometimes, therefore two opposing views about it are each only sometimes correct.

 

[Roger Hicks]

Sorry for the delay in replying. The myth is simply that an average scene reflects 18% of the light falling on it. It doesn't. It reflects about 12-14%.

This means that ANY standardized reflective surface -- the palm of Payasam's hand, a sheet of white paper, even a grey card -- can provide a perfectly splendid substitute for an incident light reading, once you make the appropriate compensation. It's just that 'the appropriate compensation' will vary according to the choice of standardized reflective surface.

Cheers,

R.

 

[Richard G]

Thanks Roger. Very well put, of course. I read somewhere that studio subjects reflect more, perhaps the legendary 18%, and that the lower figure is for outside subjects....? I re-read my M6 instructions (and the M7 referred to above) and they (Leica Camers AG) do indeed say that the meter is calibrated for 18% reflectance. But more importantly they then describe very well how to use the meter.

 

[SolaresLarrave]

Ouch, just wasted 25+ shots I was shooting outdoors on a somewhat clear sunny day.

Not necessarily. Print film can take that kind of overexposure. Your prints may look a little too bright, but not as much as to call them a waste. If your lighting was even, you're still in the safe side.

 

[payasam]

There is of course no point to metering unless one does it intelligently. To that extent, the reflectivity for which a meter is calibrated can be called not irrelevant but certainly not graven in stone: 12% per cent and 30% would both be acceptable starting points, just like the standard 18%: except that if the standard is statistically more likely to be correct, the deviations from it (correction, compensation) will be that much smaller.

Why the 18% standard, then? I for one think it unlikely that the collective wisdom of all the engineers and photographers associated with so many camera and meter manufacturers can so easily be described as barking up the wrong baobab. We should call into the debate the law of averages.

 

[Roger Hicks]

It isn't an 18% standard. This is a Zonie myth. The original Kodak research (for outdoor subjects within about 100 miles of Rochester, New York, in the late 1930s), found 12-14%.

The 18% figure is a Munsell mid-tone. Show someone a huge series of grey cards and they will pick 18% or something close to it as a mid-tone. This is not the same as the average reflectivity of a scene.

Cheers,

R.

 

[MCTuomey]

seifa, how did the pictures turn out?

 

[Roger Hicks]

seifa, how did the pictures turn out?

Good point.

Sod the theory -- and once again, apologies for the hijacking.

What about the practice?

Cheers,

R.

 

[seifadiaz]

seifa, how did the pictures turn out?

I will know this afternoon.

 

[seifadiaz]

Not necessarily. Print film can take that kind of overexposure. Your prints may look a little too bright, but not as much as to call them a waste. If your lighting was even, you're still in the safe side.

Got the print and you are correct. Everything looked good for me.

I changed the ISO to the proper value starting from around 25+ and everything was still great.