Very interesting, it has something in common the way it works with Imatest, used by EPZ and others for lens testing.

That should do the trick very nicely and produce better results more easily than what we have been doing up to now.

It's worth noting that spurious values do appear and that's a good reason for doing four shots rather than one. As in all experiments, there's a degree of error in the experiment itself.

If there are no electronic contacts on the mount you will be limited in how it can be used. Av or M only and stop down metering.

If there is an "A" on the aperture ring then set it to "A" and the lens will work normally.

I'm on the list of L&CPU judges and I'm not negative about anything as a genre. The only thing of interest is how good is it as an image. In the case of less experienced photographers, can anything be said that will help them develop their skills? And so on.

I don't see many nudes, but those I do see tend to be pretty good. Perhaps that's because it needs some confidence and ability to shoot the images in the first place and it's not usually what beginners start with in competitions.

I don't know why, but the best nudes I've seen from local clubs have been shot by female photographers.

Alcohols also denature plastics and make them brittle.

AF is done at full aperture, so the brighter a lens the more light is available for AF. An f/2 lens would allow more light through than, say, an f/11 lens so AF would find it easier to focus, just like our own eyes would.

I access the site on my iPhone and iPad without any difficulty, using Safari.

I'm interested in how you think an App would enhance this? I don't find any advantage to having, say, Facebook as a App.

Maybe what this was referring to was using the 1.7x AF converter. The original instructions say that to ahieve reliable AF the manual focus lens used should be at least f/2.8. As the converter loses light, then at the time it was issued no doubt this was right.

Whether even that still holds true I don't know, perhaps someone with a 1.7x could try it and see?

It sounds nonsense to be honest.

Cameras need light to focus like eyes do and the last time I checked Pentax were advocating lenses of f/5.6 or wider, but the whole world has changed since then. No doubt the current figure is around somewhere, and it might be f/8, but I don't think it has much bearing on things these days.

Perhaps the poster, wherever he or she was, was a little confused?

I think it's a shame that it seems to be thought of as "light at the end of the tunnel", which implies at last emerging from dark and dismal days.

In fact, the Pentax range is very attractive and there are lots of interesting and desirable products that work well, are made well and sell at sometimes very reasonable to sometimes very high prices, depending on what we're looking at.

I don't feel this terrible yearning for this light. I'm too busy using the kit that's currently available and which does the job exactly right. Still, we're entitled to yearn as well, so...look into the light....you never know.

That's great Tim, very well done!