Since I started using a dSLR I have become more dependent on autofocus, or at least on the "electronic rangefinder," ie using the focus confirmation indicator even with a manual lens.
I've been having trouble getting sharp photographs at a distance of about 100 ft, but macro shots look fine.
Is it possible for the autofocus system to have a distance dependent malfunction?
What camera do you have? With the Nikon D2X, there were reports of problems with distant focusing. Most could be attributed to the fact that the D2X has wide focusing sensors and often distant subjects were smaller in the frame and didn't cover enough of the focusing sensor--the result was the camera would focus on another object within the sensor area.
Ed
Posted by Kent Staubus on June 6, 2006 at 12:54 AM
There are also persistent reports of troubles with the D30 also.
I have a Fuji S2. I have checked the close focus. It seems fine. I angled a ruler at 45 degrees to the sensor plane and shot it. The images show that both manual and auto-assisted focus are ok.
I've been shooting a lot of stuff from about 150 feet and I have the impression that the camera focuses quite a bit in front of where the sensor is placed in the frame. It is more work than the macro check, but I'll try to check the distance focus this weekend --- I'll stick a bunch of stakes in the yard or something.
Gary - I'm seeing the problem with an 80-200/2.8 and a 300/4. I did an experiment yesterday, but my distance markers were so small that at that distance they were only a few pixels across, so the images were almost useless for judging sharpness, doh. I left my "mini clothes line at 45 degrees' out there, so today after work I'm going to retest with larger markers. I have already learned that my auto focus sensor is very specific, ie, there's a rounded rectangle indicating the sensor, but the point of focus is a tiny area directly in the center of the rounded rectangle, off to the side even withing the marked area is not the focus point. Pete D.
Discussion
5 repliesI've been having trouble getting sharp photographs at a distance of about 100 ft, but macro shots look fine.
Is it possible for the autofocus system to have a distance dependent malfunction?
Pete D.
Ed
Kent in SD
I've been shooting a lot of stuff from about 150 feet and I have the impression that the camera focuses quite a bit in front of where the sensor is placed in the frame. It is more work than the macro check, but I'll try to check the distance focus this weekend --- I'll stick a bunch of stakes in the yard or something.
Thanks for reading -
Pete D.
What size lens are you using? I had LOTS of problems with long lens with the distance that you are trying. Do you use a tripod?