Proper Incident Metering Technique (Portraiture)?

[Andre Noble]

Hello All,

I wish to simplify a question for those of you in the know. I have been using a technique of: Pointing the dome of the incident meter directly at the camera lens, and using that light meter reading on my camera.

However, I came across a second technique which seems more intuitive:

From the subject position, with the incident meter parallel to the subject's face (or if architecture, parallel to the facade of the building) pointing the dome of the incident meter directly at the main light source, and using that meter reading on my camera.

Which technique do you feel will yield more accurate results on transparency film? On negative film?

Thanks for your output

[Andre Noble]

"Select All That Apply"

[vinny]

Andre, your poll is a bit faulty since exposure is exposure. Film type is irrelevant. Proper exposure on slide film (the least tolerant of exposure error) would also yield proper exposure on any other film. Metering with the dome facing the key light with the dome shielded from other light sources is the proper method. That said, there are those who do it improperly and get away with it and yield properly exposed results.

[Andre Noble]

Metering with the dome facing the key light with the dome shielded from other light sources is the proper method.

Furthermore, Marty Seefer agrees (See: http://www.amazon.com/Art-Bridal-Por...pr_product_top) and said that he keeps the light meter straight up and down - parallel to the subject - points it to the keylight position, but does not point the dome it directly upwards to the Key light.

He didn't mention shielding the dome from other sources.

But as you can see from the early results others mostly disagree.

[Heroique]

I’ll append the following “trial narrative” to my answer, giving it an in-studio & flash-based twist, since I’m very new to flash portraiture, and would like to learn more.

I selected “dome to main light source” but of course if there’s a second flash source, I’d measure that too, the same way. (And below, I ask why there may be reasons to be a “dome to lens” person instead.) Like Vinny, I’m not quite sure why emulsion matters, but different films may have differing responses to flash, requiring tweaks to one’s method. (I hope the portrait experts around here can offer more than I can.)

So here’s the simple narrative that led to my answer:

— Let’s say I use two flashes: one is key, one is fill.
— My key is to right of camera; fill is above camera.
— I’ll assume ambient light is not a factor (in a studio), so shutter speed is less important.

*** Let’s say I want to expose for key, choosing f/5.6 – w/ fill at one stop less (creating a traditional 2:1 ratio):

Step 1: point dome to key, pop/measure only it, adjust flash power for f/5.6.
Step 2: point dome to fill, pop/measure only it, adjust this flash to one stop less.
Step 3: presumably, I’m done metering (right? but see below…), so I can set my lens to f/5.6 and take my photo, w/ both flashes popping.

Questions occurring to me:

1) If Step 1 is “dome to lens,” perhaps this would, pleasingly, make the “key side” of the subject slightly brighter than “f/5.6”?

2) And if Step 3 is “dome to lens,” for a third & final measurement w/ both flashes popping, then use of this indicated aperture would do the same?

3) And what about that ceiling-installed hair light?

I’d enjoy hearing variations on this flash theme…

[Gordon Moat]

Measure the light falling upon your subject. If you are photographing a person, the dome makes an approximation of their face, so in theory you could also use the orientation of the face of the person. When your shutter speed is slow enough, then ambient light will be a factor of exposure; many meters will allow a flash to ambient ratio reading. There are technically correct exposures for transparency films, though often a slight over or under exposure can create a more compelling rendering, or alter a colour palette slightly. When in doubt, bracket your shots.

Ciao!

Gordon Moat Photography

[venchka]

What is the correct procedure for outdoors, natural light, non-portraits?

[Andre Noble]

When in doubt, bracket your shots.

No, when in doubt, buy US government bonds.

C'mon Gordon, people don't generally have time to give up spontaneity to bracket portrait sessions exposures.

[vinny]

Andre, my statement is based on watching gaffers and cinematographers at work for about the last 10 years. The key is measured and fill is usually "eyeballed". That happens to be the way I do it as well but will take a reading towards additional units when it doubt. Working with strobes is obviously different but the practice of measuring each light is the same. Then again, I'm not necessarily talking about text book lighting techniques.

[theBDT]

I think the answer to this question depends entirely on what one wishes to do in the portrait.

Best practice, I'd wager, is to meter BOTH the key and the fill separately; as long as there isn't more than a few stops worth of difference, you're fine (unless of course you WANT blown-out or chiaroscuro effects).

Also, I have had people recommend getting the key/fill ratio on the dome to match the face; i.e. if most of the face is turned towards the fill (as in short lighting), then most of the dome should be turned towards it. I guess this method would closely match the "turn toward camera" metering technique.

This question is one advantage of having a dSLR or Polaroid handy during the shoot—to get a feel for the overall look of the reading you plan on using.