Placement

[Diapositivo]

The highlight key tone method picks the main light as the basis for exposure;
[...]
Flat face incident meter readings taken when pointed at the main source light provide essentially the same setting for the camera.

This is a measurement of incident light without regard to the camera's point of view.

[...]

This key tone method also, for me, has the huge advantage of "set it and forget it" for a given situation. Subjects simply fall normally in relation to the main light, whatever that may be. Those in full sun look like they are in full sun, those in open shade look like they are in open shade, etcetera...

(my underlining)

Mark, I don't understand you here (I think I follow you in all the rest of your well-thought post).

If we are in a situation where we use incident light metering, and place the meter on the important high light, let's say the face, the exposure will be different when the subject is in full sun and in open shade, and the placement in the characteristic curve will be the same.

This "same" placement is also what we expect as viewers, IMO.

In Rio Bravo we expect the face of John Wayne in full sun to be placed on the same point where the face of Dean Martin is placed when he sings My Rifle, My Pony, and Me in candlelight. That's because in real life our eyes adapt to different lighting levels and "place" a face on the same "characteristic curve" of our mind so to speak. We don't get the idea that Dean Martin is in candlelight by a different placement on the curve, but by a different general quality of lighting, as in real life.

What am I missing?

[markbarendt]

(my underlining)

Mark, I don't understand you here (I think I follow you in all the rest of your well-thought post).

If we are in a situation where we use incident light metering, and place the meter on the important high light, let's say the face, the exposure will be different when the subject is in full sun and in open shade, and the placement in the characteristic curve will be the same.

This "same" placement is also what we expect as viewers, IMO.

In Rio Bravo we expect the face of John Wayne in full sun to be placed on the same point where the face of Dean Martin is placed when he sings My Rifle, My Pony, and Me in candlelight. That's because in real life our eyes adapt to different lighting levels and "place" a face on the same "characteristic curve" of our mind so to speak. We don't get the idea that Dean Martin is in candlelight by a different placement on the curve, but by a different general quality of lighting, as in real life.

What am I missing?

I don't think you are missing anything.

This is a tough idea to express well.

Here's an example of what I'm trying to express, not my shot but the idea is right.

http://www.flickr.com/photos/20446524@N00/3759235528

The face falls at a point where it looks perfectly normal given the context.

If we were to simply add camera exposure to place the face in zone vi the rest of the scene would look wacked out.

In this particular example we might be able to add a touch of artificial light to get better detail on the face but the basic exposure placement is good, IMO.

[markbarendt]

In Rio Bravo we expect the face of John Wayne in full sun to be placed on the same point where the face of Dean Martin is placed when he sings My Rifle, My Pony, and Me in candlelight. That's because in real life our eyes adapt to different lighting levels and "place" a face on the same "characteristic curve" of our mind so to speak. We don't get the idea that Dean Martin is in candlelight by a different placement on the curve, but by a different general quality of lighting, as in real life.

What am I missing?

I do agree with you also that the placement of the faces should normally land very similarly on the curve.

For simplicity's sake, assuming no artificial light, the main light key tone measurements from the two scenes you describe would be many stops different.

A fresh key tone measurement is needed anytime the main light source changes or if we make a fresh decision about what's most important with regard to exposure.

[Diapositivo]

Just for clarity, I know that Dean Martin was not really in "candlelight". The way I worded my text might have been read as if he actually was in candlelight. My point was that the "candlelight" idea was suggested through light quality not face placement and that face placement tends to be always the same.

The flickr images posted is I think one of those example where one has two choices (we exclude bracketing as we are discussing exposure and placement not exposure sweeping :-) ):

-) Calm and careful metering: Spot measurement on the highlights. Spot measurement on the face. Figuring the final effect. Deciding whether to take the shot. This is my typical scenario with nocturne pictures of lit monuments, actually the light gap is normally much greater. Shot is nice IMO certainly a fill light might have made it more "normal" in any case.

-) Fast measuring: Incident light meter pointed the dome toward the light source (discussed ad nauseam in another thread). This gives certainty the highlight on the hat and bright beard is not burned and should fall "just right" on the upper part of the characteristic curve. The shadow is supposed to fall those possibly four EVs below highlight and should be in the acceptable range, although not where one would normally place the main point of interest of an image. This is my typical scenario in walk-around pictures with slides during central hours of the day. Marble buildings with the sun on their face, and plenty of seceded shadows in windows, porchs, etc. where one would hope to avoid blocking.

I have no idea what the above mentioned authors would do in this case as the three methods outlined would not seem indicated for such a situation (bracketing aside) IMO.

[markbarendt]

Just for clarity, I know that Dean Martin was not really in "candlelight". My point was that the "candlelight" idea was suggested through light quality not face placement.

I do fully understand that the scene was well and artificially lit.

In still photography though I can see using the main light key tone method regularly now for night shooting. For example in campfire scenes, streetlight scenes, and the like.

[markbarendt]

The flickr images posted is I think one of those example where one has two choices (we exclude bracketing as we are discussing exposure and placement not exposure sweeping :-) ):

-) Calm and careful metering: Spot measurement on the highlights. Spot measurement on the face. Figuring the final effect. Deciding whether to take the shot. This is my typical scenario with nocturne pictures of lit monuments, actually the light gap is normally much greater. Shot is nice IMO certainly a fill light might have made it more "normal" in any case.

-) Fast measuring: Incident light meter pointed the dome toward the light source (discussed ad nauseam in another thread). This gives certainty the highlight on the hat and bright beard is not burned and should fall "just right" on the upper part of the characteristic curve. The shadow is supposed to fall those possibly four EVs below highlight and should be in the acceptable range, although not where one would normally place the main point of interest of an image. This is my typical scenario in walk-around pictures with slides during central hours of the day. Marble buildings with the sun on their face, and plenty of seceded shadows in windows, porchs, etc. where one would hope to avoid blocking.

I have no idea what the above mentioned authors would do in this case as the three methods outlined would not seem indicated for such a situation (bracketing aside) IMO.

With long scale subjects the authors suggest the duplexed incident metering method to find the best exposure setting compromise.