There was a fad for powered zoom lenses in the nineties, with Minolta and Pentax both making very similar lenses which could be used manually or powered - in powered mode you twisted the zoom ring very slightly and the motor did the rest. I've seen something similar for Canon Eos, I think a 35-80mm zoom with power operation - except that it looked a lot clunkier, with a bulky unit on the side which presumably held the zoom motor etc., and push-button operation instead of the twist ring. But I'm drawing a blank on the lens designation, does anyone know it? And was it actually any good?
Answering my own question - I bought an old Eos 700QD with this lens yesterday. It isn't as awful-looking as I remember, I think I may have been thinking of an FD autofocus lens, but fails badly compared to the others in having no manual fallbacks at all - you can't focus or zoom manually at all. The actual designation is Canon Zoom Lens EF 35-80 1:4-5.6 Power Zoom The lens controls are two buttons, one with three trees (wide), the other with the middle of a single tree (telephoto). And that's it. It works all right on my 300D and gives reasonable results, about the same as any other lens with this range. All of the moving parts are inside the casing (even the front element doesn't move) so it's presumably easy to keep it working under wet and dusty conditions etc. But the power zoom is slow, about two seconds from one extreme to the other, and there really doesn't seem to be any point to it unless there's something I'm missing. I'll add a few photos of it later, at the moment Photobucket appears to be down.
Nope, that about sums it up. Just a product of the time, I believe it was a kit lens option for the film rebel. I actually think 2 sec to zoom is quite quick considering the age/era of the lens. From what i understood the optics were mediocre and be they are easy to pick up cheao So its best purpose now is probably as a nice conversation piece.
