[rca1]

sometimes when I try to focus on something at about 10 ft to 1.5 ft. my lens searches for the focus and when it stops it is out of focus. Not all the time?
It does it earthier inside or out. I have a Pentex K10D with a Sigma 18-200 and a Tamron 70-300. It does it with both lens but not as bad with the Tamron. I go to manual focus to take the picture. seames to work good at father distances.

[stevebrot]

sometimes when I try to focus on something at about 10 ft to 1.5 ft. my lens searches for the focus and when it stops it is out of focus.

Is it safe to assume that you get no "beep" or hexagon in the viewfinder as confirmation that focus was acquired? There are many subjects that have inadequate contrast at any of the active sensor points to allow the AF system to acquire focus. The camera will hunt and then give up.


Steve

[OregonJim]

I have a Pentex K10D with a Sigma 18-200 and a Tamron 70-300. It does it with both lens but not as bad with the Tamron.

The "superzoom" lenses are poor at autofocusing because they have such a huge range to hunt through. They also get progressively darker as they move from wide to long, which can aggravate "hunting". Placing the focus point becomes much more critical. I would set your camera to only use the center focus point. Then, find an edge on the thing you want to focus on, and place the focus point there. Or, focus manually.

[rca1]

Thanks for the reply, I will try your suggestions. I use manual when this happens. Bob