You’re in the middle of a photoshoot and suddenly you notice nothing in your viewfinder is in focus. Your shutter and AF-ON buttons (if using back-button focusing) do not seem to work. All eyes are on you, and the pressure is on to quickly fix the problem. Where do you start? Or perhaps you have just changed lenses and suddenly nothing works. Where might you have gone wrong?
This has happened to me one too many times, so I have now come up with a system of troubleshooting in the quickest time possible on the spot. It goes without saying, of course, that your camera needs to be switched to ON and the lens cap needs to be off.
#1 Autofocus not Manual
Check that both the lens and the camera switches are both pointing towards Autofocus. On the camera it must be set on AF, not M, and on the lens put it to M/A (A stands for Autofocus and M for Manual, M/A allows you to use both). Flicking the lens switch to Manual can be done unwittingly and fairly easily, especially if you are in a rush to change lenses.
#2 Back dial is not Locked
Check that the dial is pointed towards the camera icon and not the L, which stands for lock. You can easily flick this dial, especially if you are back-button focusing and your dial sees so much action.
#3 AEL / AFL
Check your AEL/AFL button that you haven’t locked focus. Clicking it once locks focus so click it another time to unlock focus.
#4 Check the lens
Remove the lens. Inspect the front and rear lens aspects for smudges or dirt. Check also that no part of the lens is broken. If you have filters on your lens, check that they are clear and there are no cracks. When you re-attach the lens, make sure you hear a click once the lens is twisted in place. If there are any smudges on the lens, make sure you clean it with a lens cloth, and do not blow on the lens.
Lens cloths are usually lint-free pieces of material, and should be used with a lens cleaning solution, rather than anything with solvents. Blowing on the lens can contribute to lens damage since a person’s breath can contain harmful acids. If you feel you have to blow, use a lens bulb blower and a brush.