Friday, April 9, 2010

Aperture preferred


With all the technological advances in cameras these days I have to admit photographers have gotten spoiled and lazy. Autofocus,matrix metering, program exposure mode, face recognition the list goes on and on. Sometimes all it seems we need to do is show up to an assignment, switch the camera on, press the shutter release and we are guaranteed of a good picture no matter how much thought or effort we put into taking the picture. It is too easy these days-right up until you walk into an assignment like this one.

Shooting the Junior Miss assignment wasn't all that hard journalistic speaking, find a good spot and wait for the winner to be announced. What was hard about this assignment was the technical end or to be more precise was the metering. I think I like to call this type of an assignment a disaster waiting to happen.

The event was held at the Grand Theatre's ETK Theatre, a nice place with good stage lighting. And there is the problem, modern cameras and theatre lighting don't mix well together. Modern camera meters are designed to do one thing, record whatever scene they see as a lovely shade of 18% gray. No matter if the scene is black, white, purple or hot pink the meter will do its best to register the tones of the scene as close as it can that 18% gray standard. For most assignments there is enough variations between light and dark tones that the metering gives me a close enough point where I can fine tune the exposure in Photoshop but take a dark theatre, black background, contrasty lighting and camera meter set for aperture preferred metering and the results will be miserable at best.

Take the stage scene, here is the problem. Lots of dark tones, black drapes and dark tone dresses with the occasional splash of a light skin tone. Lets say the camera is set for aperture preferred metering, I set the f-stop and the camera selects the shutter speed automatically. In order to record the black and dark tones as that neutral gray the camera overexposes the scene. It way overexposes the scene. it is the the correct exposure according to the camera but a dismal failure in reality. The only way to accurately metering something like this is in the manual exposure mode.

No matter what brand of camera or how old metered cameras have a manual metering mode. When switched to manual mode my Canon Eos 1D MK II gives me a scale to one side of the viewfinder. To set the "correct" exposure I have to adjust the shutter speed and f-stop until an indicator is centered in the scale. This is pretty much the same as the old 'match needle metering' systems of old. The concept is always the same though the camera wants to expose all tones to achieve 18% gray. So looking at my theater scene last night in the manual mode I knew I would have to go against camera advice and underexpose. But in reality it is the correct exposure.


Think about it, if we are photographing something black we want it to reproduce black. If the camera is going to overexpose it an attempt to get the black to reproduce gray then the correct exposure would be one that gives the correct black tone even if the meter indicates underexposed. I could have stayed in an automatic metering mode and set the camera's exposure value compensation dial or EV dial for short to - 3tops. That makes the camera underexpose three stops even if it thinks it has the correct 18% gray exposure of the scene. That might have gotten me close to the right exposure last night but what happens if I forget to change the EV setting back? Then I might be underexposing another assignment accidentally. It is easier just to go manual mode.

So how much of a difference does the metering really make? The following two photos were shot a couple of seconds apart. the top picture shows the stage area in aperture preferred with the camera assigned correct exposure. The bottom photo was my manual metered shot with a about a four-stop exposure difference. The "correct" exposure isn't necessarily the right one.


So how difficult was this to do last night? Walking into the theatre I knew the problem. it took about two minutes of testing to get the balance between black backdrop and skin tones. I left the exposure a little on the bright side so I could have some separation between the girls hair and background, I figured I could darken any hot spots in Photoshop as needed. Overall I am pleased with the exposures. It was some tricky light that required the right metering to make the correct exposure.

3 comments:

Mike McLellan, D. Min. said...

Glenn:
I read this twice and have concluded that...you are way underpaid.

Jon Mendelson said...

Great work on this assignment. Love the pic of the girl in red dancing, especially. It's hard to express fluidity in a static media.

Now, if we could just teach a certain someone about this whole "proper exposure" thingy...

Jeffery said...

You captured a great photo with the lead photo with the red dress. I am very impressed.