Auto focus speed measured with lens cap on

Started Feb 4, 2006 | Discussions thread
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Gromsky Contributing Member • Posts: 949
Auto focus speed measured with lens cap on

I timed auto focus using D70 and my AF lenses by recording the AF motor sound then using an audio editor to display the waverforms and measure the times accurately.

These times used AF.C with the lens cap on, zooms lenses set at their maximum focal length, the AF cycling from infinity to minimum focus distance and back to infinity.

The lenses marked below wit delay about 0.2 sec before reversing direction so I subtracted the 0.2 sec time out since the focus motor is not moving during that time.

Nikkor 18-70 DX 0.868 sec

Sigma 80-400 OS 1.368 sec

Sigma 18-50 2.8 1.467 sec

Sigma 70-200 2.8 HSM 1.533 sec

Sigma 50-500 HSM BIGMA 2.490 sec

Sigma 150 2.8 macro HSM 3.727 sec

In various posts in the past people have argued with me that the Sigma 80-400 OS AF was slow because it is not HSM [it does have an internal focus motor], I kept saying that it was the SOUND of gears that made it SOUND slow when in fact it's not slow at all.

Interesting to note how slow the 50-500 HSM BIG is for a HSM lens, also how the 18-50 2.8 which uses the D70 internal body auto focus motor is not that slow, the 150 macro is slow because it rotates the focus ring a long way which is expected with a macro lens.

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Gromsky

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