I use Photobucket for posting pictures here, but I don't use an actual gallery site. I have occasionally posted photos on Facebook though I don't know [m]any photographers in 'real life' so few of my friendslist are interested!

Damn, I knew I'd missed something important from the list

Yes, and IIRC only the APS-C Canons (the mirror gets caught on part of the back of the lens on FF models - not that I'd ever be buying one anyway!)

DSLR video is actually quite useful - and is the feature I miss most from my superzoom compact. Sure, it might not be as good as a video camera (though with DSLRs' much better shallow-DOF capabilities I would actually disagree with that), but there are some artistic ideas for which video is a very useful option: rainfall is an obvious one, because unless the rain is VERY heavy you can only get an impression of rain by the movement. Plus the other brands are doing video, and while "me too" isn't always a good reason for doing this Pentax do have to avoid things which might put off new users from buying into the Pentax system.

That's because "SA" is the name of Sigma's lens mount

But if you're viewing at 100% you aren't really comparing like-for-like, given the higher resolution. It's the same reason why some lenses that were regarded as great in the film days seem not as good on APS-C digital: the higher resolution sensor puts more demand on the lens performance. So with a given lens, the istD should look sharper than the K7 at 100%, shouldn't it?

[Honestly asking, all you camera physics types feel free to wade in ]

The Photozone review of the FA77 said that it is - in IQ - essentially comparable to the Nikon 85 f1.8 - that was the primary comparison I was trying to make (ie that the price difference between those two lenses is so great you can get another two admittedly cheap-and-cheerful primes and still have money left over)

Lots of reasons are suggested for the bout of switchers we've had lately: AF being too slow, or unreliable; continuous shooting framerates; or just people who haven't taken photographs of the quality they expected and want to blame the equipment. I thought I could suggest another reason, with reference to one of the 'reasons to own Pentax' namely the FA77 Limited.

Don't worry, this isn't an anti-FA77 trolling thread: it is a lovely lens, definitely one of the best AF lenses ever made. But is it better than owning all of the following and having £140 left over?

*Nikon 35 f1.8 (£169)
*Nikon 50 f1.8 (£116)
*Nikon 85 f1.8 (£330)

Now I know the FA77 has truly fabulous build quality, and is compact - but are there enough people for whom compactness and finish are important enough to pay the current Pentax prices? As I say, I'm not knocking the FA77 but in image quality is the Nikon likely to be less than half as good?

Of course Pentax has other advantages - ergonomic bodies, weather sealing [though not with the Limited primes of course], and build quality. But a nice body which you can't afford lenses for is a bit pointless, no?

The 'superzoom' lenses you describe aren't particularly cheap - the best one (the Pentax/Tamron 18-250) is now out of production which doesn't help either.

For a reasonably priced walkaround lens, your best bet would probably be the new Sigma 17-70 f2.8-4 OS HSM: it obviously doesn't have anything like the telephoto reach, but 70mm is decently long and the Sigma is both faster (f2.8 - 4 vs f4 constant) and cheaper (£315 vs £475) than the Pentax 17-70. Don't own either lens so can't comment on their optical qualities, but no doubt others here will!

EDIT: Just realised that the KM might not (ie probably doesn't) support SDM/HSM lens focusing. In which case ignore everything I just said! If you can find the old (non-HSM) version of the Sigma 17-70 (f2.8-4.5) then that would perhaps suit your needs.

What camera body do you have? One of them (can't remember which) is 'internet rumoured' to have issues with SR at precisely your 1/125th mark. Can't imagine that this problem, even if it does exist, would have any effect whatsoever on the AF confirm though.

Still: since you bought from SRS (rather than an auction site or forum) you have a six month warranty and can therefore get it fixed at no cost if you can't get it to work.