Photoclubalpha

I was over at Sony today and I got to try the 500mm mirror. I was surprised to see that the lens only has 5 contacts in the Sony version. I though it would have the distance encoder. there is a small difference though the phenolic plate the contacts are on is long enough for the extra 3 contacts so the 5 that are on it make it look like they aren't in the middle.. maybe the SSS doesn't need the distance information after all ? There was speculation that the distance was taken into account but maybe it's not as important as some think after all.

Distance information is important for an image stabiliser for several reasons ... in particular at short distances. However five contacts does not mean there was no distance information. In fact, when the AF is engaged then the camera does have distance information, no matter whether the lens has five contacts or eight.

If there is no distance information from the lens---e. g. with a five-contact lens and AF disengaged---then the camera will assume infinity as the distance. At long and medium focusing distances, lack of distance information will have a minuscule effect only.

-- Olaf

I suppose your right because the camera knows which focal lebgh your zoomed to and can tell when there is focus.. so then whats the encoder for on the new lenses?

Javelin wrote:... what's the encoder for on the new lenses?

It gives more accurate distance information, and does so also with the AF drive disengaged, with a limiter engaged, and also with SSM.

-- Olaf