Kodak carousel 2000 series

I got this for free from my camera club - wihout autofocussing. First timer at this, never saw a slide projected in my life. I have 2 lenses. Kodak Retina 51mm F2.8 and a Schneider Vario Cinelux AV MC 85-210mm F3.9.

1. How good are these and how good are general about slide projection?
2. I have yet to get a white screen. I have used both lenses against a wall in a smallish room. Basically what focal length projector lens do you guys use and how does it differ for small rooms to say a community hall room like at a camera club.


Cheers.

Kodak Carousel projectors are the gold standard for general slide projection. They work flawlessly almost 100% of the time. I have two of them and about a dozen carousels.

Depends,. Normal 12-15' wide room 4-6" lens. Auditorium longer. The Schneider 3 1/2-> 8" has it most of it covered.
You can download a manual N/C from the web that has lots of specifics.
If you want a quick & dirty solution for editing, white foamcore works but it's nowhere near as impressive.