Usually the manual is a small booklet that covers all the current lenses in the range. Have you tried Pentax themselves?

Lens testing is a very difficult area. You might have a superb example of the cheaper lens and a relatively poor example of the more expensive one, which would narrow the performance gap. It also depends on what you photograph for your test, which apertures you use. Hopefully you used a very firm tripod to eliminate any camera movement.

And so on.

Still, it's what the pictures look like that counts!

I'm not familiar with that specific lens, but in principle bayonet lenses labelled takumar are simplified lower cost options. The performance will not be as high, but if only 6"x4" prints are required it may not be noticeable. If 20"x16" prints are made, then the difference will be seen.

I don't know about the P30, but the P30T has a cable release socket on the side of the mirror housing, an unusual position that could be overlooked.

The self timer is, as you mention, another and effective approach in the right circumstances.

All the other options such a wireless remotes would require a cable release socket. I can't think of anything else you could do, unless there is some "Heath Robinson" device that has a lever that physically pushes the shutter release button. Actually, as I write that I think there might have been something like that intended for compact cameras....

Spot on, George.

Just to explain why the resolution of larger format lenses doesn't need to be as good, it's because the negatives don't have to be enlarged as much for a given print size.

A 20"x16" print from a 5x4 negative is a breeze, but from a Minox would need phenomenal resolution......

It is a lens of 18-55mm as marked, but what changes is the angle of view that it represents when used on different format sizes. Imagine a lens of this focal length on a 35mm camera - it would be an ultra-wide to standard. Now the CCD is smaller than a 35mm frame, so it only uses a part of the view, the centre of it. This is similar to the effect of zooming in.

In other words, our 18-55mm has the same angle of view as a 27-83mm approx lens would have on a 35mm camera. As we usually think in terms of focal length and not angle of view, we say it is approximately a 1.5x muliplication factor to estimate the effect of the lens compared to the 35mm format that many are familiar with.

Looking at it another way, an 80mm lens woulf be a powerful telephoto on 110 format, a modest telephoto on 35mm and a standard lens for 6x6cm.

The reason that digital lenses are often expressed in 35mm terms is that there are so many different sizes of CCD, so there is little uniformity. Relating everything to 35mm gives a degree of consistency that we can understand.

Hope that helps and doesn't confuse!

It's not a good idea to switch off whilst writing is in progress. I have seen people do it and get away with it, but it's not recommended. Personally, I would try to format the card in the camera. If that doesn't work I'd try to format it on a computer via a card reader and then also in the camera. If that fails I would try another card - cheaper than the repair by a long way.

With computers, and I include the camera as a modestly powerful computer, every time something goes wrong it's an opportunity to have a go and see what can be learnt.

I have only seen a similar thing happen once to a friend who had a Minolta. Cards can be corrupted, but usually when the power is interrupted during writing to the card. If it was very cold, I wonder if the batteries were so low in power that the write process failed and this caused the corrupted card? Just a thought.

Have you tried another card?

The Pentax *istD, *istDS and *istDL bodies will all be suitable.

George, I think you're right and the shutter will fire with the lens wide open.

I'm pretty sure that the camera will also only operate in aperture priority with these circumstances, regardless of what has been set.

It's a pity that there are these quirks in operation because of a reduction in mount compatibility, because there has been a very good record of backwards compatibility from Pentax for a long time. I suppose in the end it comes down to cost and a steadily reducing number of people to whom that backwards compatibility is relevant.

Is that the price of progress?