Back-button focusing basics: try it yourself
This practical is written so that somebody doing it for the first time can follow it without guessing. Read one exercise, do it, compare the result, then move to the next. Keep the lesson open beside you if you need it.
Before you begin
- Charge the battery or make sure the phone has enough power.
- Check that a memory card is fitted where your camera needs one and that you have space for the photographs.
- Use a safe, stationary subject unless the exercise specifically calls for movement.
- Keep the camera position and subject as consistent as possible when comparing settings.
- Do not force a control, card, battery, lens or door. If something does not fit or move easily, stop and check the manual.
1. Assign Button
Set AF to rear button (not shutter)—practice holding it.
Set up the subject first and make a starting photograph before changing anything. Check that the camera has focused where you intended. Make the change described in the exercise, take the comparison photograph, then review both at the same magnification.
Look specifically for the effect the exercise is testing. Ignore whether the subject is artistic. If you cannot see a difference, exaggerate the change, repeat the pair and make sure no other important setting or part of the scene changed at the same time.
2. Focus + Recompose
Lock focus with back button—recompose freely—no refocus.
Set up the subject first and make a starting photograph before changing anything. Check that the camera has focused where you intended. Make the change described in the exercise, take the comparison photograph, then review both at the same magnification.
Look specifically for the effect the exercise is testing. Ignore whether the subject is artistic. If you cannot see a difference, exaggerate the change, repeat the pair and make sure no other important setting or part of the scene changed at the same time.
3. Moving Subject
Track pet with back-button AF—release to stop tracking.
Set up the subject first and make a starting photograph before changing anything. Check that the camera has focused where you intended. Make the change described in the exercise, take the comparison photograph, then review both at the same magnification.
Look specifically for the effect the exercise is testing. Ignore whether the subject is artistic. If you cannot see a difference, exaggerate the change, repeat the pair and make sure no other important setting or part of the scene changed at the same time.
4. Switch Modes
Use back-button for single AF, then continuous AF—feel difference.
Set up the subject first and make a starting photograph before changing anything. Check that the camera has focused where you intended. Make the change described in the exercise, take the comparison photograph, then review both at the same magnification.
Look specifically for the effect the exercise is testing. Ignore whether the subject is artistic. If you cannot see a difference, exaggerate the change, repeat the pair and make sure no other important setting or part of the scene changed at the same time.
5. Muscle Memory
Spend 1 day using only back-button focus—build habit.
Set up the subject first and make a starting photograph before changing anything. Check that the camera has focused where you intended. Make the change described in the exercise, take the comparison photograph, then review both at the same magnification.
Look specifically for the effect the exercise is testing. Ignore whether the subject is artistic. If you cannot see a difference, exaggerate the change, repeat the pair and make sure no other important setting or part of the scene changed at the same time.
Troubleshooting
If nothing happens, check the shooting mode first. Automatic modes can prevent manual changes. If the photograph is blurred, decide whether the camera moved, the subject moved or focus landed in the wrong place. If it is unexpectedly bright or dark, check exposure compensation and ISO as well as the setting being tested. Change one thing and try again.
You are finished when
- You have completed the comparisons rather than simply reading the instructions.
- You can point to the photographs and identify the visible difference.
- You can explain which change caused that difference.
- You know what you would try if the same situation occurred again.