Oh the M42 lenses are definitely easier to work with... not so easy to mount and unmount though even so I still use m42 lenses occasionally, like my favourite portrait lens the cheapy Russian Jupiter 85mm... I don't bother using M lenses for digital any more.

Just in case you're still having doubts... stick with Pentax for Pentax glass. Using M lenses may not be as convenient or provide as many features as A lenses but it's still a lot better that having to fit them to a different mount with an adapter (where you would almost certainly have to stop down the lens yourself like with an m42 lens)... Pentax is certainly better for backwards compatibility than Nikon (even if you wanted full compatibility with older Nikon lenses you would need at least a D200), and Nikon is also probably the least flexible of any SLR system in terms of letting you use an adapter for other lens mounts, because of the spacing of their lens mounts.

For best value, I'd go for the Tokina. Except I can't. So I'd go for the Pentax and grumble about the price...

Oh I'd agree in most situations, like for example if Pentax and Nikon went the way of Minolta and for dSLRs we were all left with a choice of Canon or Canon... that's one race I definitely wouldn't want to watch... but here what concerns me is that Pentax is not yet established in digital medium format, so the risk is higher. Also slightly concerned that Mamiya are announcing this package while Pentax won't even confirm that the 645D is still happening.

No, sadly not a competition to win one...

http://www.electronista.com/articles/07/06/01/mamiya.645afd.ii.combo/

Just saw that on another forum. Seems Mamiya are also trying to make digital medium format more affordable (I use that word loosely). But $10,000 for body, back and lens - the only news of price I've heard about the Pentax 645D is from Benjikan saying that it will be three zeroes rather than four, but presumably a high three zeroes and I don't know which currency he was using.

Now assuming the 645D is not dead, cancelled or whatever - assuming that because Chris of SRS says so, and if SRS can't get the blood of information out of the stone of Pentax then no one can - but does this seem like some fairly direct competition? Good or bad for Pentax?

Isn't the 21mm f/3.2? Not a huge difference of course but still a bit slower. I've been trying to track down a 24mm f/2 or f/2.8 for a while. 28mm isn't quite wide enough. To be honest I expect the new 16-50 would be ideal for moderately wide shots on the digital but I'm still hoping for something that works on film too. Asking too much I know. Anyway the DA* lenses (the first two zooms anyway) shouldn't be pushed back much longer; I was just told I might be able to get my hands on one soon (weeks rather than months).

Thanks for the link. I see the one you're talking about now. By the way I totally agree with your choice of lenses there. 21mm I like, but would prefer something a bit faster than the current pancake. And the 200mm f/2.8 on that roadmap looks very nice indeed. The one thing I'd really like is more "D-FA" lenses that also work with 35mm film since I haven't given it up yet. But realistically I'm in a tiny minority there, and otherwise the roadmap looks very promising indeed. Hopefully once some of them are out people will pay more attention to Pentax, shops will stock them and third-parties will make alternatives. Well ok I thought the same about the K10d and it didn't happen, but I can hope...

Right... but those other supersonics are fast zooms, which are usually pretty large, are they're still smaller than an equivalent lens for 35mm. "DA" usually indicates a lens designed for the digital sensors, meaning the projected image circle doesn't have to be as large as for 35mm and therefore the lens can be smaller.

Edit: what 55mm are we talking about here? I can't actually find any references, except to a 55mm f/2.8 for the 645D. Which of course would be larger.

[quote="Tyr"]Can't see why it would be bigger and heavier than the FA 50 f/1.4. Same focal length and same max aperture. If anything I might expect it to be smaller, since it would presumably be designed for the smaller image circle of the sensor like the other DA lenses.

It's a great lens. f/1.4 is certainly useable, of course it's a bit soft but that's to be expected. As 'iceblinker' says, cost does not always indicate quality... the f/1.4 does not cost a lot of money for what it is, and it certainly costs a lot less than the equivalents from Canon, Nikon or Sony. Pretty good value in my opinion.