Help regarding understanding exposure book

[lilkafra29]

To those who read the book, I did not understand what is meant when you are recomposing and why does the author said use -2/3 exposure sometimes. Also what does setting the exposure matching the sky? I'm confused. Thank you for all your help

 

[Vinny]

Recomposing means to take a meter reading of the subject, lets say the subject is in the center and move the camera's viewpoint where the subject isn't in the center anymore.

The reason for using -2/3 exposure is that the meter can be fooled by certain objects and he is compensating for the meter being fooled. If you are shooting in manual adjust your settings for the meter to read -2/3 vs "0" or if in an auto mode use the exposure compensation that's built in to some (all) cameras.

I asked the same question about the blue sky here as well ... he explains it later in the book but the blue sky will give you the correct exposure to take. IMO, he should have explained it in the beginning.

There is a portion of the book that he explains about using a grey card and the relationship between the sky and other items (don't want to give his book away) and I just ordered a grey card to play around with what he was talking about. Not that I don't believe him just want to reinforce the idea that he was writing about.

 

[clanthar]

And sometimes you should also use -1/3 and +1/3 and -1 and +2/3 and so forth. The problem for beginners is they don't know when and why to make those changes. First you have to understand why.

Reason one: The light meter in your camera is a reflected-light-reading meter. It works well enough but will always contain a degree of error due to the way it works. The meter reads the light after it has bounced off the subject. Ask your self this simple question; will a white sheet of paper and a dark denim jacket both reflect back light at the same rate? How does the meter in your camera know which one is which? Look at these photos:

There are three photos here -- the photo of the two cars and then, below the silver car, a photo of the door panel just under the handle and, below the charcoal car, a photo of the door panel just under the handle.

The camera meter did a good job on the photo of the two cars. It averaged all the different reflective rates together to determine exposure. However the camera got both door panels wrong. The silver car door panel is too dark and the charcoal car door panel is too light. They're not true to the subjects. In the door panel photos the camera had only a single uniform subject and so was unable to work an average.

Principle: When the average of the different reflectance rates in a subject is "normal" and the camera can calculate that average, a reflected-light-reading meter does good. When the average of the different reflectance rates in a subject is not normal the camera meter gets it wrong.

Armed with that knowledge you can eventually learn to anticipate the errors your camera will make and compensate with -1/3 or +1/3 or -2/3, etc.

An alternative is to use a meter that does not make errors: That requires you to meter the light before it hits the subject. Then your meter reading is always 100% accurate:
Sekonic-Exposure Meters-Color Meters-Illuminometers

The grey card is a way to accomplish the same thing. You place the grey card in the scene and meter from that thereby avoiding the unique reflectance properties of the subject.

The problem with using an incident meter (or grey card) is that it's often impractical. So in the end you're best bet is to learn to see the lighting and anticipate your camera's error and compensate.

Reason two: some other time.

Joe

P.S. A clear blue sky at the correct angle can be very close to a grey card and so provide a useful meter reading. Problem with this is it's really variable and you're more likely to get bad info from this method than not -- not recommended.

 

[lilkafra29]

Thank you very much for your answers. I tried to experiment on my photos yesterday and I now understand when to use the -2/3 but I got a 2 out of 5 photos. I'll try to post them and have it CC. Thank you!