autofocus - How do I focus a Nikon 50mm f/1.8?

I recently bought this lens, but it seems to me that it hunts a lot in low(ish) light, and sometimes (often) does not achieve focus at all. I never had any problems with the kit lens.

Pointing the AF sensor to a place with higher contrast helps, but no t always.

Even with the AF assist light on, it sometimes fail to lock focus and I have to change to manual focus.

Any recomendations?

Thanks

Answer

I have the same lens on my Nikon D50, and found it has major problems focusing when not using the center point of focus. When using the left,right,top,bottom focus points, it will run the whole focus range without finding something to focus on.

When using the center, it will focus, except when the center region is completely flat (without any detail to focus).

So, maybe try to lock the focus point in center to see how it reacts.

In general, the focus speed of the 50mm 1.8 is far slower than focus speed achieved with the 18-55 kit lens.

(I also have the 35mm f1.8 DX and it does not suffer from this problem, it has similar performance as the kit lens)