Don't have that battle guys. There are no winners.

Telecentric first. Especially with wide angle lenses, the light exiting from the rear element can be quite diverged, so the rays hit the film at an oblique angle. This is fine for film but digital sensors have each pixel sunk slightly in a pit. It is much better if the light rays are parallel and fall at 90 degrees onto the pits and hence onto the individual pixels. This problem is worse the nearer the rear element is to the sensor, so the K mount has a good back distance for lens design, whereas small CSCs and Leica rangefinders do not. In theory it is easier to make higher quality lenses for the K mount.

Chromatic aberration was not such a problem with film so corrections were not quite so high. It only really became a problem with long telephoto lenses and hence the increased use of extra-low dispension (ED) lens elements. With digital the effect is exaggerated, presumably because of the interaction of the light with the construction of the sensor causing diffraction effects at the edges of images.

Edge sharpness refers to the sharpness at the edge of the format frame, not at the edge of the image circle of the lens. The performance at the edge of our APS-C format images is just as important as ever it was. That's got nothing to do with film formats.

Now when we use a lens that can be used with film, we are only utilising the central part of the image the lens could produce. So it's likely that the lens will perform well at the edge of the APS-C frame. However, other factors will negate this advantage to some extent, such as the lens not being telecentric and such as poorer correction of chromatic aberration than would be the case with a digital lens.

Generally on digital I have found that digitally intended lens designs are better. One classic exception to this is the set of three FA Limited lenses.

First I would clean the contacts, then make sure that nothing has been inadvertently set to disable the flash hotshoe.

If all is still not well, flash circuits on cameras very, very rarely cause problems. I suppose it's possible that if you have been using an older flash with a very high trigger voltage you might have damaged the circuits.

Otherwise, warranty repair if possible or paid for repair if not.

All is now well. Title corrected, although I think we knew what you meant!

OH it works JAK, make no mistake about that. Shots are now possible hand held that would have been a faint hope before.

Thanks for reminding us - yes, there is an orientation sensor, but that's not big enough to clunk. The clunk is SR for sure.

We have K-5 and K20D cameras and I prefer the K20D design, but there are other factors that mean that we mainly use the K-5.

In fact, if all things were equal, performance and WR-wise, I would be using a K-r, which I think is absolutely superb ergonomically.

This is no doubt operational noise from the SR system. The instruction manual tells us to expect it and that it is quite normal.

Because that's how they enjoy the event cabstar. There isn't just one approved way to enjoy something.