Projector Lens 16mm
Special thanks to Dr. Film
The standard projection lens for 16mm is the 2". Lenses can be had from 1" to 4" for most projectors. The longer the lens, the smaller the projected size image for a given distance. The 1" lens will project an image approx twice the size of a 2" lens over a given distance. Unless you have a very long or short throw to the screen, the 2" or a 1.5" lens will do the job in your screening room. Check out Screen Size Charts 16mm to ascertain your screen size with various length lenses.
Once you determine the length of the lens you need, you should then considered how much light it will pass to the screen. This is indicated by it's "F" rating. The lower the better. An F1.2 will produce a noticeably brighter picture than an F1.6
Lastly, you must be certain that the diameter of the lens will fit your projector. For example, Bell & Howell lens diameters vary from model to model and most manufacturers use their own diameter. The following table should help you determine the lens diameter for your machine.
BELL & HOWELL 100-200-300 SERIES - 1.156" DIAMETER
BELL & HOWELL 500-1500-2500 SERIES - 2.062" DIAMETER
DEVRY-B&H-RCA-JAN-VIEWLEX - 2.062" DIAMETER
GRAFLEX-SINGER-KALART-RCA 400 SERIES-AMPRO - 1.184" DIAMETER
GRAFLEX-SINGER 1100 SERIES-LARGE BARREL - 2.062" DIAMETER
KODAK PAGEANT SERIES - 1.156" DIAMETER
ELMO-ALL SERIES-KODAK CT1000 - 40mm DIAMETER
EIKI-ALL SERIES - 42.5 mm DIAMETER