I'm just about to start the process of revamping my kit, and in fact have already started selling off my excess lenses on Ebay. Here's the plan for the new set up and any thoughts and comments would be gratefully received:

35mm - Keep existing 15mm f3.5 K, 20mm f4 M and MZ3 body. Add to line up 24-90mm Pentax zoom and 100mm Pentax Macro lens. Keep MX body as back up.

645 - Build on existing 645n with 75mm lens. Add 35mm and 120mm Macro lens.

The 35mm kit will be used almost exclusively with tranparency film either for projection or scanned and printed. The 645 kit will be mainly for monochrome use and conventional darkroom printing.

Any ideas?

The SMC Pentax-M 40mm f2.8 lens was introduced with the MX and ME models. It is called the "pancake" lens because it is very thin and only adds the slimmest amount to the depth of the camera, making these two SLRs very "pocketable".

It consists of 5 elements in four groups, focuses I think to around 2 feet and produces stunningly sharp pictures. The only disadvantage is that the focusing ring is so thin (just a strip of rubberised grip) that with a lens hood in place it can be difficult to find room for the fingers to focus the lens!

All Pentax fit K mount lenses will work on all Pentax bayonet bodies but the features available will differ. So, for example, M series lenses have no 'A' setting so cannot operate in shutter prioroty mode, but they are fine for aperture priority and manual modes. Screw mount lenses can be fitted via an adapter, but have to be stopped down to working aperture to meter.

So, within some limitations, which may or may not be of importance to you, I would expect the lens you are interested in to be useable.

Only general comments, but first of all I would try replacing the camera batteries. Some Pentaxes will lock up the mirror if battery power is too low. Also never, ever, pull or push a SLR mirror anywhere, in fact avoid touching mirrors at all. If the mirror ends up even slightly out of alignment your pictures will not be in focus.

Other than that, it could mean a repair job. Hope the battery suggestion works!

This is a difficult one to predict - it depends on the halogen lighting. I sell to dentists and we use halogen bulbs in dental lights, but the colour teperature can vary from 4000K to 5500K. It can, therefore, be very close to daylight, but it could be much redder.

I would be inclined to shoot a test film and try the films required without filtration and also with an 80A (light blue correction) filter. Then see which colour balances suits.

As regards the amount of light, if you are using a tripod there will be no problem with camera movement. What about subject movement? Perhaps if light levels are too low you could consider faster films?

Another thought - if you used a card reader to download the pictures it might be more convenient than using the camera.

Only the very basics - check all the cables, re-install the software, get any updates or patches for the software via the internet, try any helpline number (as a last resort because of the cost!).
Every time you get a computer problem it's a bit of a steep learning curve sorting it out, but I guess something gets learnt every time!
One last thought - if you are using some other application before you try to download images from the camera it might be grabbing and holding on to the port. Try restarting the computer and downloading from the camera before anything else.

Is there no socket for the electronic cable release? All the pentax bayonet bodies will take your AF lenses, operating within the limits of the various bodies. Why not go for the MZ5n or MZ3, both of which accept the electronic release.

You can't use the bayonet lenses on the Spotmatic II (unless you possibly had a special adapter made at some large price) but you should be able to buy screw thread zoom lenses in perhaps the Tamron Adaptall range or similar.

I would suggest the advert pages in AMATEUR PHOTOGRAPHER - search through the listings and perhaps make a few phone calls to likely suppliers.

One problem I see is that modern designs may not be suitable for the limited 42mm throat of the Spotmatic's lens mount, so some of the more exotic lenses may be unusable anyway.

Good luck!

Speeds of 1/75 and faster will operate without batteries on the LX. It could just be that new batteries are needed to utilise the slower speeds. If the batteries are low it could be normal for the mirror to lock up as a warning.