Summertime Nature in New Jersey. Sourland Mountain Preserve.
Bullfrog in a Pond at the Sourland Mountain Preserve. Recently there have been a lot of messages on the internet regarding some users of the New Nikon D800/D800e camera having issues with autofocusing. Specifically, that the left autofocus sensors are not focusing accurately. I tested my D800 camera with a test chart — comparing the CAM3500FX contrast based autofocus system with the Live View phase based autofocus system. I did not find any significant difference between right, left, and center contrast based autofocus, all being equivalent to the Live View based focus.
Rather than spending a lot of time testing each lens, I took the camera out to the local Sourland Mountain Preserve and took the following images of a Bullfrog. The images were taken with the D800 camera and a 500 mm f/4 VRII lens. The lens was mounted on a tripod, and the images taken in “Mirror up” mode to minimize vibration. I was approximately 20 feet away from the bullfrog, which is near the minimum focus distance for this lens. The lens was wide open (f/4) which means a very narrow depth of field in sharp focus. I did the same shot with the head of the frog in the left, center, or right most autofocus sensor, each time re-focusing from infinity. If anything the image from the left sensor was the sharpest. I think the softness for the image from the right sensor is due to vibration.
Focused Using Left Sensor.
Focused Using Left Sensor (100% Crop)
Focused Using Center Sensor
Focused Using Center Sensor (100% Crop)
Focused Using Right Sensor
Focused Using Right Sensor (100% Crop)