I am pretty sure that from the K-3 (or maybe it was the K-3II) Pentax bodies stopped working with Sigma HSM lenses correctly when using a teleconverter with SDM contacts. From what I remember it was when Ricoh bought out the Pentax 1.4x, they released a firmware that supposedly fixed an "issue" with SDM but in the process it stopped the Pentax converter working with Sigma HSM lenses. I always thought it was to stop us using the new 1.4x with Sigma HSM and In the process it also stopped the Kenko and Teleplus converters that had the SDM contacts from working with Sigma lenses as well.

Really annoyed me at the time as my Sigma 70-200mm OS HSM started mis focusing straight after the firmware update as did a couple of other HSM lenses I had.

Could have been just my experience though.

But I have just seen the Z 800mm PF Nikon are releasing soon .... I think it may be time to seriously think about selling up everything and concentrating on one "do it all" system instead of using 3.

£729 (mint condition from the looks of it)

Amazon have got just the outfit to go with it

I hope you contacted them to see if they would reduce the price before you bought it, LCE are pretty good like that. I did out of interest and they said they would knock off £30

Looks like the black one has gone already but both are a bit of a bargain, hopefully one of the 2 people interested in mine managed to grab it.

Saying that I should have sold mine and bought the black one

Sat here all this time then 2 offers in 24 hours

Anyway, when it came to the crunch I just couldn't let it go so withdrawn from sale.

For £189 posted I think it's worth the risk, especially as it comes with 6 months warranty.

When looking for an idea of price I usually go onto eBay and look at sold prices for UK over the last 3 months.

Totally agree the 150-450mm is the better lens but then it should be considering the cost.