The Sony A6000 has an AEL button, while Nikon SLRs have an AE/AF lock button. What do these do that half-pressing the shutter to lock focus and exposure, and then recomposing, doesn't? I'm used to the latter method, and never used a camera that has a dedicated button.
I read that you have to keep both the AE/AF lock button pressed and the shutter half-pressed while recomposing. Isn't this harder than just keeping the shutter button half-pressed?
I'm aware that you can customize the AE/AF lock button to lock only focus, or only exposure, or both. This leads to two follow-up questions:
- Can't you customize the half-press shutter to lock only AE or only AF?
- If you don't care about this level of customization, does the AE / AF lock button do anything that half-pressing the shutter doesn't?