This gives some of the details about the chair photo.

The photographer who took the 1st photograph would probably be the owner of the copyright if anyone owned it, but it would probably be from just one position.

I'm basing this on the photograph taken in the 60's of Christine Keeler sitting the wrong way round on a chair with her arms on the back of it. The photographer later successfully sued someone for using the same pose. It was stated in AP at the time that an earlier photo with the same pose had already been published in AP, but the problem was proving that the photographer who took the CK photo had actually seen it.

At least it's still the current model

Nobody thought of that!

Well you could always have a Canon one instead!

A split-screen isn't that accurate anyway. I mentioned in another
thread that I've just tried my old ME-F with the 35-70mm AF Zoom
and it still works a treat Switching to a MF 50mm f/1.4 the
Green light is very sensitive much better than on digitals. It
even lights up 2 red arrows showing which way to focus, but the
split-image shows in focus even when the red leds are on.

No idea how it knows which way you have to turn the MF lens

Hi and Welcome Did you ever use that quite nice camera
shop in Congleton? I think they closed about 10 years ago. They
used to stock quite a bit of difficult to get Pentax stuff like
flashleads lens hoods etc. along with lenses and cameras. Good
SH stock as well.

Chris.... you need to buy a Copipod before your camera
tips over..... It happened to me once

Cheap plastic vials used in spirit levels are very accurate.
A 1M long level very often has a certified accuracy of +/- 0.5mm in 1M
You can usually buy just the vial from a toolshop or "on the market."
Very handy for leveling up tripods etc.

The type Chris is using should be of a similar accuracy. The way to check
them is put them on a flat suface that shows level, then turn though
180deg if it still shows level it's accurate. You could do that on a
tripod.

I've no idea how accurate the built in levels are, they will be
based on an electro-mechanical plumb-bob. Pentax know all about building
electo-mechanical levels from their surveying instruments which
are usually accurate to about +/- 3mm in 50M. I doubt if the camera
ones are that accurate though.

The screen catcher is a good idea, even for someone just removing a screen.

I notice that your original page has a link to greyhounman's site in which he says the DS and ME Super screens are both about 1.5mm thick.

I think some of the Chinese suppliers use a FF Nikon screen, which is widely available retail.