Tokina 100-300mm F4 constant PK mount

LBA is good fun. Anyone know much about this lens - from what 'the google' tells me it's quite good. Would compliment my new 50-135mm DA* quite nicely I think.

However, what would this be worth?

So not much info then. How bout in regards to this compared to a Sigma/Tamron 70-300mm non-constant aperture then? The latter would have AF on it, but I imagine the IQ would be worse.

You mean this lens? link
Doesn't look like they have a K-mount version of that one.

Some users review Minolta mountlink

http://www.rokkorfiles.com/100-300mm.htm is the one I'm talking about - much older! Seems the other forum mentions it, but not in much detail. Some say it's good though. I think one sold for $300USD or thereabouts on their marketplace.

I'm just not sure if it's worthwhile or if it's more of one of those 'don't waste your cash' things. I already bought a 55mm Porst f1.2 in K-mount today, and the reviews on that are mixed (I think it's going to be a gem).

Why not buy a DA55-300 for a little more?

Think the IQ would be better? I kind of like the idea of a F4, just wish it had AF on it.

I've no idea...

Just checked the newer version of the Tokina 100-300mm f4 versus the Sigma 100-300mm/4 on Photozone.de and, obviously, the Sigma smokes it. The big downside is on the Tokina is the CA. However, it does slaughter the 70-300mm . All those links were for the Canon platform because they don't have the Tokina on the Pentax in their reviews.

When comparing the Tokina to the DA 55-300mm, it has similar CA, and is much faster overall... Much better 'overall' resolution, but at 300 the DA is sharper in the centre. Gah, I hate choices! I want someone to blame if I don't like it

The DA55-300 is however lighter and smaller than the Tokina and you've AF but that's quite slow on the lens.

What about the Sigma 120-400mm, it's however double the price of your budget though, don't know if you can get lucky second hand?