Long Lenses for Pentax

As a self confessed addict when it comes to Pentax kit I am looking to extend my lens collection to give me a bit more reach than my current Pentax 150-450mm and Sigma 500mm F4.5.
I have been watching a Pentax FA 600mm F4 and a Pentax DA 560mm F5.6. Prices for both are similar and would no doubt require me to sell other kit to finance it, so I need to make a good decision!
I understand that the 600mm is a full frame lens and a stop faster (and heavier!) while the 560mm is lighter, dedicated for APSC and has Pentax weather sealing. Do any of you have experience of these lenses? How do you feel about them both in terms of handling and optical performance?
I predominantly use the K-3iii with my longer lenses but live in hope (rather than expectation) of an update to the K-1ii

Any thoughts would be appreciated

Stephen

No need to apologise, my own expectations are pretty low as far as future development goes. However taking a positive view, I expect my current kit to long outlast my ability to use it so quite happy to indulge myself with some older glass.

I have dabbled with Sony and Olympus and now have some of the latest Canon tech, but I still keep reaching for my Pentax kit as a choice not just muscle memory

The K3iii will always give you more reach than a K1, with a steady hand or monopod / tripod imho just crop in for the extra reach

Hi all,

I'm going through similar thoughts across a range of areas currently. Still running my K-3 from many years ago.

I have the plm zoom to 300mm but looking to get more reach, or get more quality at that point.

Am considering:

An upgrade to a K-3 iii IF i can find one I can afford. They're tended to hold their value and I tend to buy second hand when the price falls to within my budget range. The K-3 iii's are proving difficult to find though and if I do they're around the same price as new?!.

Upgrading to a 300mm f4 (not sure on the SDM reliability but the optics of a prime should be better than the current zoom).
Am also considering the 1.4 AF teleconverter on this (wouldn't consider on the PLM zoom).

Upgrading to a Sigma Bigma of some sort, though there are a wide range of options here I'd need to research.
Ideally after something with inbuilt lens stabilisation and the best long range image quality past 300m.

Gut feel has changed from the bigma to the 300mm prime, probably with a teleconverter.

Any thoughts/feelings welcome!

The 300mm f4 + Pentax 1.4 TC on a K3 kept me happy for many years. They play very well together and the image quality is very, very good. No SDM problems, either, and I believe that the lens can be converted to screw drive if SDM does fail. The reason they aren't on a K3 now is that I eventually got a K3iii. However, compared to the K3 I haven't found much difference with the 300mm + TC attached (the K3iii was acquired for other reasons).

Another possibility is the Sigma 100-300mm f4 + Pentax 1.4 TC. Image quality is very, very good and it works well with the Pentax 1.4 TC. I got one in order to have a zoom with f4 all the way to 300mm. If I'd had one before the DA300mm f4, I'm not sure I'd have wanted to get the DA300mm as well (OK, I lie, the pull of a prime would have been too much to resist for ever...). It is screw drive, though, so not so good for when you don't want to be noticed!

Steve

Highly recommed the Pentax 150 -450 especially on a K1 or a K3iii

I'll post a few images shot at a motor event last weekend in a day or so.