Actually with a bit of levels adjustment and a little sharpening, I think you might be surprised how good that can look, if you'll forgive my taking the liberty.

It was hovering, presumably, so isn't quite germane to this topic, but handheld, for 1/10s at that focal length, that is excellent.

Indeed. I think this is another one of these unsubstantiated myths that are entirely without foundation, and would be almost impossible to test.

Imagine a camera that was moving at constant speed in a straight line. The accelerometers that measure shake (in order to tell the electronics to move the sensor in a direction countering the shake) would detect nothing at all.

Superimpose shake on that movement, and the sensors would detect it in the same way as they detect it in an otherwise stationary camera, and counter it in exactly the same way.

Of course, panning a camera by hand is only an approximation to such steady movement, and it's not impossible that if you accelerated the camera suddenly to follow the subject, and pressed the button at the same time, the camera might be attempting to correct for what it had suddenly detected as shake.

But even then, it would be impossible to know that that had happened, and in any case, the camera's SR wouldn't yet have stabilised - and as we know from Matt's experiments on that topic, unstabilised SR can be worse than no SR at all.

However, none of this comes even close to substantiating a claim that SR on a panning camera causes blur. My panning isn't bad, but I couldn't claim to be able to pan the camera steadily enough to be able to tell the difference between SR on and off with an already fast shutter speeed.

I say leave it on.

I've had several of the non-APO versions; they come in MF and AF variants. They're light, easy to handle, but soft and dreadful chromatic aberration wide open. Stopped down to F8-11 they're much better - reasonably sharp and less CA.

Colours not great, probably due to the CA - slightly muddy compared with the natural look of Pentax lenses. Sometimes this matters, other times not. I've had some good results, and some awful ones, the latter including attempts to photograph aeroplanes with the AF variant when the 55-300 did very well indeed.

The APO version is supposed to be better, but I have no direct experience of that.

This is certainly true for the K10D (and, I'm sure, Emma's GX10).

I have both screw-in, and Cokin P linear polarisers, which I thought I'd try out first before getting the CP that almost everyone insists you need.

They're absolutely fine - since getting the K10D in Jan 07, I've never known any issue with either the metering, or the AF, either or both of which are supposedly affected. And I have looked quite carefully for such an issue.

Saved me a lot of money - good CPs are expensive.

If the Vulcan is flying at the Shoreham airshow, it certainly won't be taking off or landing there. The runway isn't anywhere near long enough.

There are two ways that I know of.

One is to use a pre-A series lens, or an A-series lens (or FA series) not set to A. The pop-up then doesn't emit a pre-flash, and triggers the Xtra flash just fine.

However, you'll have to do all the exposure manually, and ensure "Use Aperture ring" is set to permitted in the Custom functions.

The other is to use an old non-PTTL flash gun in the hot shoe to do the triggering.

Edit: or a PTTL gun in A or M mode. I've just tried it with the Samsung version of the AF 540, and it works fine. Again, you'll have to get the exposure sorted out by trial and error, I expect.

If you're triggering the Xtra flash from the pop-up, it'll be the pre-flash that triggers it.

So by the time the shutter opens, the Xtra flash is all over and done with, and will contribute nothing to the exposure.

It may be even worse than this - if the camera's metering sees any of the light from the Xtra flash, it may, in addition, think the scene is brighter than it is.

Underexposure is pretty much guaranteed, without there being anything wrong with the equipment.

Based on the test I ran and described last year, I believe this is incorrect.

I used the compatibility chart on the CameraClean web site.

(and it was only £100+ cos I bought an Arctic Butterfly first )

Well, it happened over a pretty short space of time. Previously, there'd been the occasional few bits of, presumably, dust, and the Rocket Blower would shift them easily. Then, seemingly over just a few short weeks, all that crap you saw in the first picture appeared.

I wonder if it was pollen - apparently that sticks. Maybe I was just unlucky. You'd think it would be all over the inside of the lenses too, if it is - I'll see if I can see any. It's not like I've left the camera out with the front uncovered.