WTB: Minolta Maxxum AF 2x Tele Converter APO

Does it seem logical for the high speed TC to enable the combined TC & lens to focus 4 times as fast (at lower effective aperture, longer distance) as the native lens? I think the gearing probably slows down the combination, (ie the later TC is geared to focus slower then the earlier), I would check the gearing on either of the 2X TC's, or the later 1.4 X TC if I had one.

Edited by mirthseeker - 18 May 2019 at 01:18

Cekari wrote: An iPhone shoot of it: Minolta AF 2x APO D TC by Lars Hernborg, on Flickr

I had to look that one up. I had no idea these were out there! AFter some research I see they were made to be compatible with SSM Minolta lenses. I presume these are identical to the Sony's currently sold. (and like the Sony's, geared the same as the APO ii versions).

Cheers

Mike

sybersitizen wrote: Cekari wrote: I found this but doesn't help much as it was on an old forum: "There are two versions of most Minolta TCs. While both will work with the same lens, the high speed version gives faster autofocus with the high speed lens but slower autofocus than the standard converter with a non high speed lens. " That's almost nonsensical. If the gearing is lower in the new TC it will produce slower AF with both old and new lenses than with the old TC. If the gearing is higher in the new TC it will produce faster AF with both old and new lenses than with the old TC. As I said, I have seen claims that the new TC is geared lower and claims that the new TC is geared higher, and I don't recall seeing any real substantiations in support of either claim.

But bear in mind that a faster motor drive + gearing doesn't necessarily imply faster AF, for example if the AF is no longer stable but oscillates for a while before settling. I have seen this with some older lenses, and it is due to the gearing (and inertia of the moving parts) not matching the electrical damping in the servo drive. Under damping means several cycles of motor drive before settling.