Camera advice ?

[gbb]

Bit of a long shot..
Nikon D40 DSLR. I have two of them and am re-aquainting myself with them after many years of not using them.

Focus...in the viewfinder, one has a ring display to assist with focus , when youre not in focus the ring is misaligned, it helps you focus really accurately.
The other camera (same.model) doesn't have that ring and despite looking everywhere In settings, I simply cannot find out how to turn it on.

Any advise / experience ?

 

[gbb]

Sorted. One camera has a plain mirror, the other has the focus rings on the mirror itself...so I will just use the appropriate camera body.

 

[nogoodnamesleft]

Pre-DSLR, just on SLR my old Olympus OM-1 (the original proper one, not the modern use of the reputation associated with the name) you could change focus screens. Easy to do, get the screen of your choice. Different screens were better suited to different lenses eg my 800mm mirror was a lot easier with one type of focusing screen vs the screen better suited for general use. Get the screen of choice, take the lens off, flip a small catch and the screen drops out, put in other screen and it clips back in. Takes seconds and done.

No idea about more modern cameras and no idea about D-40.

eg for OM-1 (original SLR not modern version) https://esif.world-traveller.org/om-sif/findergroup/focusingscreens.htm