Just over an hour ago.

What you can do with a piece of 1/8 inch welders glass.

[IMG]http://i162.photobucket.com/albums/t244/chris5gd/Technical/IMGP1028.jpg[/IMG]

Very interesting point, John.

To test this, fast shutter speeds would be needed, to guarantee that there was no shake in the image when SR was off. This would be true on the tripod, too, of course, because only when the shutter is manually released, can SR be off anyway.

All my SR-related studies have been looking for SR causing shake during long exposures, not at all at sharpness at short exposures, with and without the sensor being able to move.

It would be very ironic if the real reason Pentax say leave SR off on the tripod is to do with achievable absolute sharpness, as you say, rather than the widespread and IMO unfounded claims that SR causes shake.

I don't know whether the differences we're talking about (between the sensor locked and mobile cases) are large enough, but if this were the case it may explain Don's astonishing observations too. Because if absolute sharpness achievable with the sensor fixed is higher, then images that are already shake-free might be better with SR off.

But it's a tall order getting shake-free images with long exposures off-tripod.

Please, please could someone explain why this is so????

Wasn't it already at 100%?

It is true for this one, and it was quite exciting as the moment approached. I took a series of seven as they ran in, one shot every two seconds or so. You can see the series - they run from 15 to 21 in this gallery.

It was helped by the fact that I've watched the Red Arrows so many times over the years that I've got a pretty good idea of what they're going to do.

I took these in 2002 with an ME Super, and a Sigma 28-200 F5.6, and you can see from number seven that it's a very common 'pose' for them. Hopefully I've come on a bit since then

Although as I say, getting it right is still so rare that it feels like a fluke when it happens.

I would suggest this:

If you're concerned about your camera's focusing, this thread may be useful.

Find out for sure whether the camera is focusing properly, and fix it if it isn't.

Then stop worrying about tiny amounts of noise in underexposed parts of photos, which is normal, and usually means you need to work on getting exposure right.

I do see this, but it's not a lot. As I said earlier:

The thing is, underexposed areas (and especially, as you say, if they've been pushed a bit), will very frequently show a bit of noise.

This is very different from an overall noisiness, that I don't think is evident on these pictures, and certainly not enough to suggest that there's anything wrong with the camera or the lens.

How far out was it originally, Peter?

Or maybe you do

What is your monitor, by the way?