In-camera metering under indoor bulbs gives two stops underexposure

[domagojs]

(I don't know where to post this question, so feel free to move it to a more fitting forum)

I noticed a very strange thing and want to ask if that's a known fact, or am I doing something wrong? Namely, under incandescent light indoors at night (so the only light is coming from bulbs) meters in my Bessa R2A and Nikon FM2 both give me readings for two stops underexposure. On the other hand, my dSLR reads the light perfectly!?!? If it would be only one film camera, I'd think there's something wrong with it, but tonight I tried both at the same time and compared the readings to dSLR and both film cameras were consistently off by 1 or 2 stops.

Is this some well known fact that you have to compensate for incandescent light by giving two more stops exposure than indicated, or am I doing something wrong?

 

[hamish_gill]

What metering pattern do you have the dslr set to?

 

[domagojs]

matrix metering, i just rehecked.

i also tried "zooming" in on my subject and the meters in film cameras showed the same exposure. also, the angle of view was the same on all three cameras, 50mm.

 

[Joosep]

Umm... Thats the way it should be ?

 

[sevo]

Matrix metering will ignore areas with a bright light source - weighted average meters can't, so they'll lose out in extreme contrast situations.

And some films, e.g. Fuji Acros, lose more sensitivity in light with low colour temperature than accounted for by the meter calibration, while digital cameras tend to fully compensate their internal AWB speed loss.

 

[hamish_gill]

try the dslr on centre weighted meter and see what happens ...
the fm2 has a centre weighted metre so you should get same or similar results.
The r2a meter is a little more complicated http://www.cameraquest.com/voigtbmeter.htm

 

[Roger Hicks]

Many films are slower to incandescent light than daylight, but typically just 1/3 to 1/2 stop. Also, the meters may have a disproportionately high red sensitivity, again leading to underexposure. Even so, 2 stops sounds more like metering error than anything else.

Cheers,

R.

 

[Landshark]

Are the lights visible to the meter? If they are the camera will give a smaller f/shutter indication.

 

[Pickett Wilson]

Matrix metering is smart. Center weighted averaging meters are dumb. They can't interpret all the light levels in a scene like the matrx metering can. Ain't technology grand!

 

[ferider]

What kind of bulbs / light ?

Several times I have observed some of my light-meters going crazy under special lighting (Neon, Halogen, not sure .....). What I know is that the light flicker at a frequency that my eye can't see but the camera meter does.

Then, shots like this can happen:

The two vertical black stripes are interference of the shutter curtains with the frequency of the light source.

Roland.

 

[David Hughes]

Hi,

Light bulbs don't compare well with sunlight. Some colours are missing and meters cells don't respond to all colours and so it could just be a mismatch between the two. Having said that, I wonder if the "smart" metering is doing something because of the light's colour or what? A couple of stops seems too much. Perhaps a grey card etc might give a different reading?

Regards, David

 

[Sparrow]

What kind of bulbs / light ?

Several times I have observed some of my light-meters going crazy under special lighting (Neon, Halogen, not sure .....). What I know is that the light flicker at a frequency that my eye can't see but the camera meter does.

Then, shots like this can happen:

The two vertical black stripes are interference of the shutter curtains with the frequency of the light source.

Roland.

The rule when photographing anything AC, CRT tubes or lighting and the like is to stick to the same shutter setting 1/50th here in the UK where the power is 50Hz, 1/60th for the US ... otherwise one simply tests the shutter's speed