K10D vs K20D

The impression that I had was the later, it would allow SDM lenses to remain SDM with the T/C in place.

I agree George, the 1.7x AF converter was an artifact of the MF/AF changeover period and wouldn't be as popular now. An SDM pass through converter would be a much better idea.

There are reports that some converters with PZ passthroughs already work with SDM, which is handy. I think the REALLY important feature of a Pentax converter is not that it be SDM compatible, but that it be SR compatible.

Going by the silly prices asked for them, I would say very popular and hard to get.

http://cgi.ebay.com.au/Pentax-F-AF-Adapter-1-7X-Rare-NEW_W0QQitemZ280160799543QQihZ018QQcategoryZ4688QQrdZ1QQssPageNameZWD1VQQ_trksidZp1638.m118.l1247QQcmdZViewItem

they only command high prices because:

1: they are the only Pentax converter which supports AF at all

2: they are scarce on the used market, most people who have one don't want to sell it.

They are not particularly attractive to people who want to use them with AF lenses because of the way they work. For this reason, in the modern climate where most people's primary arsenal is AF lenses, a simple pass through converter will sell better.

The presence of a DA pass through converter on the market will turn the 1.7x AF into what it should be, a curiosity valued by collectors and the odd person who has an old A* prime or two. The 1.7x converters price will drop, and everyone will be happy.

Everyone except the owners of 1.7 converters!

G