Here's a promotional idea - they should get John de Lancie to appear in advertisments for the Pentax Q.

For those who don't remember, he's the actor who played the character of Q in various versions of Star Trek.

All bayonet Pentax fit lenses can be used. If there is an A on the aperture ring they will be fully functional, if not they can be used manually.

Screw thread lenses are used via Adapter K, which gives manual operation.

This is a very abbreviated explanation, but you can be reassured that virtually everything can be used.

Good decision becausae he will be able to use his existing lenses as well. The operational style will also be familiar, so it will make life much easier.

A K-r twin lens kit package would be a pretty good place to start.

I personally wouldn't want to make any recommendation for this as I don't do that sort of photography and I haven't used all three lenses. I can only say that the 60-250mm is capable of stunning quality.

The technique often used for racing cars is simply to focus manually on a place on the track, wait for the cars to arrive just before the closen spot and release the shutter. We fire the camera just before the moment to allow for the very slight shutter lag on a DSLR. It might be as musch as 150ms so a fast car moves a significant distance in that time.

This works equally well for bikes and I don't see wht it couldn't be used for karts as well.

This is a major consideration - what is your photographic style and what sort of images are you hoping to make with the lens you choose?

Given that both lenses are equally excellent in practical terms, the choice is down to other factors. Do size and weight matter? Does the reach of the lens matter? Does the maximum aperture matter? These things will sway the decision one way or another.

If it helps visualise the effects of both lenses, the 50-135mm is similar to what we would expect a 70-200mm lens to be like on film. The 60-250mm lens is similar to what would have been a 90-375mm lens on film.

The DA* 60-250mm is also a constant f4 throughout its zoom range. I am selling an "as new" one at the moment.

My experience is that the Pentax lenses are generally superior in many ways. They fit better, operate more smoothly and usually offer better performance.

One undersetimated benefit is that the colour balance of the images is very consistent from lens to lens. This will not be the case where makes of lens are mixed.

There are more sensor manufacturers than Sony and they will all want to sell their sensors. I think Sony, Toshiba, Samsung and Kodak all make sensors and maybe many more.

Copy stands labelled P mean "portable" and this is the same copy stand that is current at the time, but the base is built into a carrying case.

I can find references to it in the 1970s, but not by 1984.