Posted on July 15, 2016
While I’m a huge advocate of manual metering (it’s all I’ve ever used), I stop short of saying everyone shoot shoot in manual mode. But I do believe that anyone who is serious about their photography should at least be comfortable shooting in manual mode. That means understanding how a light meter “sees” a scene, the information the meter returns, and how each of the camera’s three exposure variables affect an image. (I won’t get into the rudiments of metering now, but you can brush up here: Exposure basics.)
We have three ways to control the amount of light our sensor records:
Every image you capture uses a combination of these three variables to establish the exposure (amount of light) for every image. And because the variable you choose to adjust affects more than just the exposure of your image, if you can’t justify your choice for each of the three exposure settings for every shot (if it’s not a conscious decision), you have a wonderful opportunity to improve.
To illustrate, I’ll explain my exposure choices in the dogwood image above (a new image, captured during my 2016 Yosemite Moonbow and Wildflowers workshop in April). Though I used f/8, 1/125 second, and ISO 1600 to achieve my desired exposure, keep in mind that I could have achieved exactly the same exposure by choosing f16, 1/4 second, and ISO 100. Or f5.6, 1/500, and ISO 6400. Or a virtually unlimited variety of other combinations that all would have captured the same amount of light. But since whatever exposure combination I decide on will potentially yield a completely different image (different depth, different motion, different noise), I had to be very careful with my decisions.
So here goes:
This was my process and rationale for this image. Depending on the factors I’m dealing with, my process might follow a completely different path for another image.
In general I tell people just learning to master manual metering to approach every scene with a tripod (non-negotiable—with no tripod, my suggestions below aren’t valid) and this mindset:
These guidelines certainly don’t apply to all situations, but they’re a good starting point that will simplify the decision making process until you get more comfortable juggling your exposure variables. And keep in mind that you’ll need to deviate from f/11 and ISO 100 whenever your creative needs and the scene conditions (such as wind or moving water) dictate. Practice makes perfect.
(Images that required a very specific combination of exposure variables)