Metering

[colyn]

Here's your assignment.. You have a 35mm camera with a 50mm lens. You point it at a near distant subject with lighting from highlights and shadows like you would see on a sunny day. You set your asa to 100 and shutter speed to 125th. You meter it with the builtin center weighted meter and and note the exposure settings indicated..

Now you meter the same subject with the same settings but with an averaging hand held meter from the same spot where you metered with the camera meter and note the exposure settings..

Will both meter indications be the same or will they be different??

 

[CMur12]

I would say that, in theory, the readings would be the same.

If the photographer knows the performance characteristics of the camera meter and the handheld meter, the two meters should be usable to produce consistent results.

Variables that could appear in practice:

1. The camera meter can get different readings with different lenses, depending upon the light transmission of each lens. A handheld meter won't reflect this, though it would be less of an issue with a 50mm lens than with a complex zoom.

2. The effect of center-weighted metering (rather than full-average metering) on whatever is being evaluated.

3. The angle of acceptance of the handheld meter. Is it reading exactly the same thing as the 50mm lens on the camera?

4. The camera meter and the handheld meter might not be completely in sync. For example, if both were pointed at a blank wall that exceeded the coverage of both meters, one might be out of adjustment relative to the other. In most cases, if the meter isn't adjustable, the photographer knows the difference and adjusts the ISO accordingly or compensates mentally.

That's what occurs to me for the moment. I often use TTL metering and handheld meters together, taking into consideration their relative performance characteristics (spotmeter vs incident meter vs calibration, etc).

- Murray

 

[Ko.Fe.]

I wouldn't use meter with ISO 100 film. 😀

 

[CMur12]

I wouldn't use meter with ISO 100 film. 😀

Problem solved! 😎

- Murray

 

[colyn]

This can be done at any film speed.

It's simply a test..

 

[SolaresLarrave]

I have done this with different cameras and different meters. There's always a variation range (like +_ 1 stop). The only difference is that I've used ISO 400 as my standard, along with a focal length of 35mm.

With my Nikon D700 (set in average metering mode) I get a particular EV that varies slightly from the one in one of my M6TTL bodies. Compared to the EV I get from my silver M5, they are not the exact same (must keep in mind that the M5 has a spot meter), but then, they're within 1.5 stops. This means that, at 1/500 of a second on a very sunny day, the D700 will give me something like an f14, while the M6TTL registers a good EV between f11 and f16. I cannot recall exactly the M5 meter suggestion for the f-number, but my handheld meter was somewhere in between the D700 and the M6TTL. My electronic meter (Sekonic L308B) overexposed a bit (slightly below f11).

After this experiment, my conclusion was that as long as I get a decently exposed frame, the EV really doesn't matter to me.

Sorry, Colyn... I don't know what you expected but if this was not it... I'm sorry.

 

[CMur12]

This can be done at any film speed.

It's simply a test..

My first thought when I saw your original post was that it was a trick question, as the proposed scenario is pretty basic.

Your statement here that "It's simply a test.." tends to confirm that suspicion.

So, what are you up to? 😕

- Murray

 

[CMur12]

Looking more closely at the original question, about meter indications being the same or not, I would say that actual indications would probably be a little different due to the fact that the meters aren't likely measuring exactly the same thing. It would be the photographer's interpretation of metering data that would make them consistent with each other.

- Murray

 

[Roger Hicks]

Hand the same meter to five different photographers. Ask them to meter the same scene and wrote down their readings for a given shutter speed to the nearest 1/3 or 1/2 stop in lens aperture. I would be astonished if all five readings are identical. Just try it. The total spread might even be more than 1 stop.

Cheers,

R.

 

[colyn]

My first thought when I saw your original post was that it was a trick question, as the proposed scenario is pretty basic.

Your statement here that "It's simply a test.." tends to confirm that suspicion.

So, what are you up to? 😕

- Murray

The purpose of the post was to validate and SolaresLarrave hit the nail square on the head..

I recently sold a Nikon F2 with DP1 metered head. The buyer took it out this last weekend and noticed the meter readings were different from his MR-4 clip-on Leica meter and thinks the Nikon meter is off and he has not even processed the film. I know the Nikon meter is reasonably accurate since I have used it to expose a number of rolls which came out looking good.

I tried to explain to him the differences between meters but he does not buy it and SolaresLarrave's explanation is what I gave him..

 

[colyn]

Hand the same meter to five different photographers. Ask them to meter the same scene and wrote down their readings for a given shutter speed to the nearest 1/3 or 1/2 stop in lens aperture. I would be astonished if all five readings are identical. Just try it. The total spread might even be more than 1 stop.

Cheers,

R.

I couldn't agree more. I have even gotten different readings myself..

 

[Roger Hicks]

Garry Coward-Williams, last editor but one of Amateur Photographer magazine in the UK, phrased this whole question very elegantly.

Given the quite wide variations in readings of the same subject when they are taken by different photographers and with different meters, how is it that so many photographers get adequate, good or even perfect exposures?

My suspicion is that it's because photography is rarely as precise as some people imagine. For "imagine", read in many cases "delude themselves".

Cheers,

R.

 

[Timmyjoe]

There's a reason that folks who want really accurate light readings use an incident light meter, not a reflective (sp) light meter (like Colyn is talking about). As Roger says, give five people the same reflective light meter, have them meter the same subject, and they'll probably get five different readings. So many things can effect the light reflecting off a subject; reflectance, background intensity, angle of light striking the subject, etc.

If you want an accurate exposure, read the light striking a subject, not the light bouncing off.

My 2¢ worth.

Best,
-Tim

 

[BLKRCAT]

Im with timmy.

You never specified how one was using the handheld meter. If it was me and I was incident metering I would most certainly get a different result than a reflective reading.

You also have to take into account what the center weighted meter is pointed at. If its reflecting more light back or less light back it can throw the reading.

Now, I can get the meters to match if I evaluate the scene. I will need to point the camera to all parts of the scene and see exactly what the light is and adjust my settings according to the look I want.

Roger is a wealth of knowledge in how to meter correctly. Just search his past posts on the subject.

 

[Roger Hicks]

There's a reason that folks who want really accurate light readings use an incident light meter, not a reflective (sp) light meter (like Colyn is talking about). As Roger says, give five people the same reflective light meter, have them meter the same subject, and they'll probably get five different readings. So many things can effect the light reflecting off a subject; reflectance, background intensity, angle of light striking the subject, etc.

If you want an accurate exposure, read the light striking a subject, not the light bouncing off.

My 2¢ worth.

Best,
-Tim

Dear Tim,

Um... Not always.

If you are striving for maximum "accuracy", you'll use incident light for transparencies and digital (exposure keyed to highlights) if you can -- it's not always feasible -- and true spot metering (1 degree or less) of the shadow areas (NOT mid-tones) for negatives where the exposure is keyed to the shadows or for transparencies and digital when you are forced to read highlight because you can't get close enough with the incident meter.

If you really know what you're doing, in the other hand, you know that just about any metering system can be made to work because you'll know all the "fudge factors". The rest of the time you'll use another metering system or bracket.

Cheers,

R.

 

[SolaresLarrave]

In my latest experiences with an unmetered camera, I've chosen to bracket... first, as the meter tells me, then over and under. More often than not, the "correctly" metered scene is nice, but then one of the other two is nicer. Who knows? As I said before, as long as my frame is exposed the way I envision it...

I tried this years ago with my two M6TTL bodies and a Summicron 50mm. Neither had produced poorly exposed images (and back then I used to shoot ALL THE TIME with E-6 stuff). When I saw what the cameras did I nearly fainted and screamed "this camera needs repair!"... but then it occurred to me that both cameras have worked well for me... always, so, let metering quirks be.

BTW, I was indoors and using artificial light (which, unlike sunlight, never varies). Explanation anyone?

 

[colyn]

You never specified how one was using the handheld meter. If it was me and I was incident metering I would most certainly get a different result than a reflective reading.

You also have to take into account what the center weighted meter is pointed at. If its reflecting more light back or less light back it can throw the reading.

When comparing two reflected light meters, you will get different readings. For more precise readings you should use the incident meter..

Most reflected light meters are calibrated to 18% reflectance so one way to check meter accuracy is to use an 18% gray card and meter only the card (no out of bounds). I use 100asa 125th @ f/16 but even this does not guarantee absolute accuracy because of the many variables in light affecting the subject.

 

[Timmyjoe]

Dear Tim,

Um... Not always.

If you are striving for maximum "accuracy", you'll use incident light for transparencies and digital (exposure keyed to highlights) if you can -- it's not always feasible -- and true spot metering (1 degree or less) of the shadow areas (NOT mid-tones) for negatives where the exposure is keyed to the shadows or for transparencies and digital when you are forced to read highlight because you can't get close enough with the incident meter.

If you really know what you're doing, in the other hand, you know that just about any metering system can be made to work because you'll know all the "fudge factors". The rest of the time you'll use another metering system or bracket.

Cheers,

R.

Come on Roger, if you can't get close enough with an incident meter, it's not worth photographing!

😱

I stand corrected, or I should say, sit corrected.

Best,
-Tim

 

[BillBingham2]

Can I take this thread sideways........

In some cases, the proper exposure is a subject thing. Depends upon what you are trying to communicate.

B2 (;->

 

[SolaresLarrave]

I agree with Bill... besides, isn't there a mantra that goes something like "for transparency meter the highlights, for color print meter the neutral and for black and white on the shadows"?