Originally posted by Hokonui Either, auto would be convenient but I can work with manual if that gave the better image quality option.
Originally posted by Hokonui The Sigma 50-500 would be a good option but best price I can see at the moment is around $1000 US.
(NZ isn't big enough to have much used Pentax gear available locally so I'm pretty much reliant on what turns up on Ebay or Pentax Market for used gear).
I'm happy to spend $500 and might manage $1000 ... but definitely prefer the former.
Tokina 400 5.6 looks interesting, as does the Pentax 55-300 PLM with 1.4x converter option.
Thank you all for the suggestions, much appreciated.
If you can find one, the Pentax A 400/5.6 is probably the best one can do for the lower end of your price range. A couple years ago I would see them for around $400 USD, but I see fewer these days.
The A 400/5.6 is very sharp - and even nicely sharp wide open - has excellent build quality and a lovely focusing throw that is smooth and precise, if a bit long. It's light enough to be easily hand-holdable for most folks. The one bugaboo is chromatic aberration when used at f/8 and wider, although the CA can be mostly ameliorated in your image editing program.
Using a manual focus tele lens requires dedication, though. I see many photos made with long MF teles posted here and elsewhere that are soft or even blurry, most often due to poor focus. To get the best results from a MF tele, you need to "live the life".