Join Tim Grey for an in-depth discussion in this video Back button focus control and focus lock, part of Learn Photography: Autofocus.
- With most cameras, if you have autofocus enabled,…that focus is established as soon as you take a picture.…In other words, if you press the shutter release button,…the camera will autofocus, make sure that focus…has been established, and take the picture,…all very quickly, of course.…You can also generally establish focus first…by pressing that shutter release button halfway…to establish autofocus, and then releasing,…if you no longer want to take that picture…for any reason, but then continuing to press the button…the rest of the way to actually capture the image.…But I find it very convenient to essentially separate focus…from the process of establishing exposure…or of actually taking the picture.…
In other words, my preference is to not…have the shutter release button activate autofocus.…Instead, I prefer to use a different button on the camera.…This is a feature that's available with many cameras,…but it's also enabled, or implemented,…in different ways, depending on the particular camera…that you're using.…
Photographer and educator Tim Grey explores these questions and more in this exploration of focus and autofocus. And because sharpness isn't everything, Tim also details scenarios where blur can have more impact.
- What is focus?
- Calculating depth of field
- Looking at focus limitations
- Employing autofocus one shot vs. continuous
- Using manual focus
- Setting and choosing focus points
- Controlling depth of field
- Using intentional blur and bokeh
- Finding focus while panning