Originally posted by Shelob1 all I can say is what the guy in the store read on the converter itself. I know very little about converters, but I know the SP range is highly regarded and that is why I am interested. Plus it is at a good price. Is there a website which lists all Tamron products?
There are two models of Tamron Adaptall 2x teleconverter, the 01F and the 200F. The latter is very rare and commands high prices when it appears for sale. The 01F is very common and sells for cheap ($10-30). I got mine for free, because it came attached to a lens I bought on eBay.
This is a good converter but it is not very versatile. As it is fitted with an Adaptall mount, it works only with Tamron Adaptall lens. You will not be able to use it with any other lens you might own. I suggest you buy a Tamron 1.4x AF Teleconverter for Pentax AF instead. It is available new, the price is OK and it works with any lens, because it is fitted with a standard Pentax KAF mount.
Find everything about Tamron Adaptall lenses on this great site:
Adaptall-2.com
Chers!