Metering tricky scenes

[ebann]

I'm doing Neil van Niekerk's wonderful flash course and the first subject covered is exposure metering.

http://www.planetneil.com/tangents/exposure-metering/

The tricky scene with the two guys with sunlight and shadows, what exactly is Neil recommending?

(1) Manual Mode

Ok

(2) Spot metering

Ok

(3) Where to meter?

Not the subject, i.e. the two men because he says "By basing my exposure on the two men in the sunlight, the shadow areas will become dark shapes." - Aren't we desiring that our subjects be well exposed?

The lit wall I believe - "then I moved my camera to point to another subject which was completely sunlit" - Why would the two men be well exposed in this case as compared to the above?

(4) If using a constant aperture zoom lens (e.g. 70-200/4, It wasn't clear on this: IF I zoom in to 200mm and meter the wall using spot metering, AND then I zoom out and keep the same metering, I would get the correct exposure? This metering would work at any focal length? Reason being, zooming in helps eliminated any interfering dark shapes and nail a precise spot. If one was at 70mm, the dark shadows might affect the spot metering (if spot is somewhat large), more so on center-weighted.

Thanks for any help.

[Moose408]

It sounds like he is recommending using spot metering to get the approximate exposure then using manual mode to lock it in.

[RDKirk]

That was an amazingly non-informative article on exposure. There are much better available on the internet.

It's amazing that he never tells you what an exposure meter is calibrated to produce.

Look again at the picture of the two men. Look carefully at the concrete at their feet. Notice that particular shade of gray. That is about what we call "middle gray."

That tone, that particular tone is what the exposure meter is calibrated to reproduce. If you go into spot mode and read exclusively that particular tone, the resulting image will reproduce that particular tone accurately.

If you measure a lighter tone, the meter will give you a reading that will render it as that same medium gray. If you measure a darker tone, the meter will give you a reading that will render it that same medium gray. No matter what tone you measure, the meter will always give you a reading that will render it the same medium gray.

The only time the meter will give you a "correct" reading is when the tone you're measuring actually is the same medium gray the meter "thinks" it sees.

Now, it is a matter of happenstance that most landscapes and cityscapes--Wonderment!--just happen to "average out" to that medium tone. Grass happens to be close to that medium tone, and so does the mixture of grays in most cityscapes. So most blind meter readings will turn out mostly good results.

If you measure the skins of a pale Caucasian and a very dark African, the meter's readings will render their skin tones the same medium tone. But because skin tones are usually within a stop of that medium tone, they're usually easy to correct in processing, so again, most blind meter readings turn out okay in the end.

But let's presume you want to do better than just okay. Once you realize that the meter is always trying to render every tone as a medium gray, then you begin looking for something that should be medium gray and metering that.

But better is to check the web for the "Zone System" and look at the Zone System scale of tones. That way you can learn to see how far in stops different tones vary from the medium tone. You will see, for instance, that most Caucasian skin tones are one stop brighter than medium. That means if you measure a Caucasian skin, you would want to add a stop to whatever reading the meter gives you (because the meter is trying to make it one stop darker).

Knowing what the meter is actually telling you is just the first major step in learning exposure, but it's an essential step, and I would not spend long reading anyone claiming to be teaching exposure who doesn't cover that very early in his teaching.

[PhotosGuy]

My actual method of exposing for the men, was to put my camera into manual metering mode and then I moved my camera to point to another subject which was completely sunlit, and I set my exposure reading accordingly. He used something like this:
Need an exposure crutch? (http://photography-on-the.net/forum/showthread.php?t=89123)

[ebann]

He used something like this:
Need an exposure crutch? (http://photography-on-the.net/forum/showthread.php?t=89123)

Thanks! That helps a lot but I have a question:

In Neil's example, let's assume he's about 50 meters away on a sunroof of an adjacent building.

1) Is it correct to assume that the sunlight hitting my palm (or grey card) is the same light hitting those men even though we're 50 meters away? The sun being a light source at (virtually) infinity.

2) Can I extend this assumption to a gym scenario? Suppose a gym being uniformly lit by many lights hanging on the ceiling about 25 meters up. Could I meter my hand (or greycard) and assume that the light is the same as on the court.

I could deduce that if the central court is being lit with extra light this assumption will not hold, e.g. like an auditorium stage being better lit than the audience area.

Your gym example, you mention metering the coach's white shirt. Is this the case where the court was lit differently from where you were shooting from?

Thanks for your help!

[PhotosGuy]

Sorry to be late.
1. Yes.
2. Maybe. All HS gyms I've seen have spotty lighting, but it's usually better in the middle. I was in the stands & the coach's white shirt was in the middle at the VBall net.
Usually when I get there before the games I'll check the exposure at the ends of the court & make a note. RAW processing helps take up the slack.