I had a problem with an unbranded card a while back. I use adobe photodownloader to transfer the files off and it stopped after the 20th picture and wouldn't transfer the rest.

I then tried manually copying them off in blocks of 10, which worked. Then one of the blocks of ten wouldn't transfer, so I worked my was through that bunch, file by file. eventually I got them all of, except for one corrupt file. I then re-formatted the card and tried shooting all many of junk just to fill the card, tried to access the files and something similar happened - failed on a file.

I then looked at the card really closely and found that it was cracked around the contacts, so I retired the card.

RescuePro and similar are primarily designed to recover accidentally deleted files. To recover seriously damaged cards (or disks) you need a "zero assumption" tool.

Well first off you will lose a couple of stops of light. And unless the converter has contacts for the AF system, your AF lenses become manual ones.

There is an AF converter http://kmp.bdimitrov.de/teleconverters/F1.7X.html which turns your manual focus lenses into auto focus lenses (I think you set the lens to infinity and the converter sorts it out)

Here's the thread with the Tamron 500mm mirror examples

https://www.pentaxuser.com/forum/viewtopic.php?t=5767

courtesy of Gartmore

Their main advantages are small size and low weight for a long focal length. I have the Centon, and it's "ok". Someone around here posted some shots recently, which were taken with (i think) the tamron and they were far better than I get with the centon.

I'd like to be earning what you must be earning, then!

Having just looked at the "current" lens road map, it still shows a lens for the now canceled 645D!

No FF lenses in the Pentax Road Map.

He sings pretty well too!

If you hang around the perimeter of Heathrow long enough (say 5 minutes) a nice man in a blue uniform carrying a big gun asks you to go away.

And if your telephoto lens looks like a shoulder-launcher then.......

Guilty to everything!