I wouldn't bother to mix K batonet and screw mount lenses on one camera body, but if I had lots of screw thread lenses I might use a dedicated body with an adapter more or less permanently attached.

Swapping about in the field would be slower than just using K mount lenses, or screw thread lenses, and mixing seems a bit inconvenient. Unless you feel you really want to do that.

You could use the clone tool, going right down to pixel level to ensure a precise cut out, but it would take a very long time. Maybe using selected parts of the subjects rather than the whole plane would be an easier option?

It would need to be a small aperture, especially on a larger format where DOF is reduced. With slow films such as were available in 1922 that means either a slow shutter speed (everyone sat still) or a lot of light (flash or inandescent lights out of frame).

It would be interesting to see the technique used, and somewhere in the magazines of the day no doubt there's an article on the subject. I can't recall reading one (from my collection, I wasn't buying them in 1922!) but there must be one.

Ten years ago this would have been an amazing question, but now that digital photography has taken over almost entirely it had to happen!

The "gelatin silver print" is the black and white print process that has been ousted by digital. In other words, standard traditional black and white paper, processed in a darkroom. Printed from a negative.

Yes, you can still do this, and many people still do. You need an enlarger, chemicals, trays, a red safelight, etc. and the process is very rewarding. Black and white film is still available - all you need is a film camera to put it in.

The name "gelatin silver print" is the fancy name that is put on what we might term "fine art prints" and the quality of a black and white print can be truly staggering. A book or computer screen cannot do justice to the very best printing on photographic paper and I would really urge anyone to go and see some quality exhibition prints to see just what is possible.

The lens is a competent performer, slighly faster than usual for a four element design. Wide open it's nice as a portrait lens, stopped down it's sharp and contrasty.

Not having SMC coatings it is more prone to flare, but no more so than any other conventionally coated lens.

The Pentax Adapter K is still available new.

The technique is to attach the adapter to a screw thread lens and then bayonet it onto the camera. That lens can be unscrewed and replaced as desired, effectively turning the body into a screw thread one.

When we want to remove the Adapter K a small catch has to be released with a small tool sometimes provided or the tip of a pen or mini screwdriver. The adapter can then be gently rotated and dropped out into the palm of the hand.

Some do indeed say that the Silver Oxide cells cause no problems. The books say that it will cause exposure errors.

Wein cells will last about 6 months. Mercury batteries lasted 12 months at least, as I would expect Silver Oxide ones to do also.

Just imagine, all us Digital Users - not changing a battery for a whole year! How technology changes things....

The Wein cell is the correct 1.35v. Obtainable from The Small Battery Company.

No, it might be better than my Pentax lenses and then I'd be very upset....

Although it would be possible to use it on bellows on the K20D. There's no focusing mount so it would have very resticted use. We'll see how it does on eBay after Christmas.

The 24mm f2.8 was always one of my favourites on film.