Well, you can in CS3 (Filter > Distort > Lens correction) so I'm sure you can in CS4.

What did you use for those pictures?

I like these. Terrific light on the wet sand.

I'm troubled by the apparently curved horizon in the last two though. Is it a real distortion?

Let's hope you're right.

I want upgraded high-ISO performance and (sorry all) faster AF, especially in low light, before I want shiny silver to measurebate to.

Not bad..

I'd be interested to see the results from the D300s out of frame to the right

Well of course, there will always be AF situations that no camera can cope with.

Is my example really one of them, though?

I also have a long-tailed tit visiting my pear tree that I'm trying to capture. I've missed many shots because the time to frame and focus is just too long. I can frame, but then during the half second or so of AFing it flies away.

The issue is simple: if no camera can cope in these situations, we should all shut up about AF and just practise more. If Pentax is lagging behind the others, they should come under pressure to improve.

I don't want to switch brands - I want Pentax to be better, and the impression I get is that in their higher-end cameras at least, the others' AF is more capable in the difficult situations.

I know all the value-for-money arguments, too, and again, if I'm still simply demanding too much at the sub-£1k price point then I think it needs to be clearer - at least to me.

I might add, as I mentioned before, that I don't think it's quite enough to just say "well, MF, DOF, pre-focus then", in all the tricky situations. I can do that with a £20 second hand camera. For many hundreds of pounds, I expect the automatics to be better than me.

Ok, so techniques for seagulls moving fast at close range with a K10D, then, please.

I can do aeroplanes, no problem. Even when they're coming towards me at more than 250 miles an hour, continuous AF is good enough.

But seagulls trying to catch bread out of the air at a range of 20-50 feet, and I'm really struggling.

Oops, I ticked 'No' after checking it all out, rather than before. I'm pre-coffee, sorry (another RTFQ here). I mean 'Yes' - no matter how hard I look, I can't see them as the same.

I so wish the forum software let you retract a vote... cos I didn't mean to cheat, honest guv.

Anyway, this is possibly the best visual illusion I've ever seen in my life.

I copied A to a new layer in PS, and converted it to a smart object, so I could move it around the screen with the mouse.

It's not the same, goddammit - the square changes colour as you move it around!!!!

Like Pentaxophile, even though I know the truth, my brain just recoils.

When I first looked at the picture, I could see straight away that B is much darker than the other light squares at the sides, and also that A is much lighter than the dark squares in the middle. What still completely amazes me is that they still look very different.

With other illusions, I can usually mentally remove the context and focus on the bits to be compared, until I can see them as the same.

I just can't do that with this one. It's brilliant.

Careful - that point is (almost) unarguable, and that would never do

But that's the thing, isn't it - it's not just a simple fact. There are so many variables - camera, lens, operator, subject, light level - that it's very hard to generalise. The consensus does seem to be that the high end Canons and Nikons have faster AF than we're used to, but that's not the whole story.

If Dan can take awesomely sharp pictures of birds in flight and I can't, with the same camera, the likelihood is that there's something defective about my technique. Or it might be that his lens focuses faster than mine.

Teasing out these things is hard, and wading through the uninteresting bits goes with the territory.

The best thing to do, if uninterested in a topic, is just not read the thread.