Different between Focus Lock

[niranjan]

Hi,

As i learn the Halfway Press of Shutter Release button will lock the focus on my subject.
I wish to know the difference between focus lock achieved by pressing FOCUS LOCK BUTTON (on my Nikon its AF-L near viewfinder) and the lock achieved by pressing the shutter button half way..

regards

 

[Solarflare]

That differs between AF-A, AF-C and AF-S.

 

[Dao]

For action type photos, if I shoot with AI Servo (continuous focusing), using the back button in my Canon is better than half press shutter. I just use my thumb to press and hold the back button to focus on the subject and then snap the photo with the shutter button.

 

[tirediron]

There is no difference in the actual focus; using either the AF-L button or the 'half-way' shutter press results in the same focus being acheived. The AF-L button is an option to allow you to focus/lock focus without having to press the shutter release. Some people find it useful, others don't. It depends greatly on your shooting style.