telephotos lens inquiry

[Moogle Pepper]

Ok..

So I recently picked up a 70-200 L lens from here... but I been wondering in the lens barrel there is a switch under the AF\MF that has "1.2m- infinity and 3m - Infinity" What exactly does it mean? Is it the closest I can get to a subject?

[LiquidAir]

The 3m-infinity setting prevents the AF from focusing on objects closer than 3m. It is handy when you are shooting through something nearby and can also speed of the AF algorithm.

[Moogle Pepper]

The 3m-infinity setting prevents the AF from focusing on objects closer than 3m. It is handy when you are shooting through something nearby and can also speed of the AF algorithm.

ohh ok and I will presume the 1.3 is the same thing, only within the 1.3 parameters.

[LiquidAir]

ohh ok and I will presume the 1.3 is the same thing, only within the 1.3 parameters.

The other setting is covers the full focusing range of the lens.

[Moogle Pepper]

oh..

Thanks! This is the first telephoto lens I have gotten.

[sirsloop]

If you notice, right around half of the AF rotational distance is taken up by 1.2m-3m. By eliminating that you effectively double the AF speed in hunting situations.

[claudermilk]

Exactly. If you know your subjects are going to be farther than 3m, limiting the AF throw speeds things up significantly.