I have just recently started to explore the things I can do with a flash.
When I started, I had no idea what TTL even meant. This article over at Craftsy is a great piece of information for anyone like myself. It’s going to be so much easier to practice now that I’ve learned the basics first!
TTL, or Through the Lens, is a system for determining the correct exposure for a photograph when using a flash.
When your flash is set to TTL mode, and either on the camera or controlled with a TTL device, it is automatically controlled by the camera and responds to calculations of exposure with more or less light. This is great technology for photography, especially beginners who aren’t sure where to start with flash and for photojournalists who might not have time to get the settings just right without missing their shot.
Many times, the camera’s best guess is very good. Other times it is not, and that is why learning how TTL works is helpful.
Factors that affect exposure
As we have learned in other posts, there are a few factors that affect how light or dark a photograph appears and if our exposure is correct:
- Shutter speed
- Ambient light
- Artificial (flash) light — both intensity and distance
You can choose to set none of these and let the camera decide for you, or choose one or more and let the camera compensate by adjusting the others. For example, if you have your shutter speed set to f/4 and your ISO set to 400, the camera may determine that your shutter speed is going to be 1/60 and the total exposure is still two stops dark, including the ambient light.