[old_tv_nut]

I never heard of a portable or consumer grade 35mm film projector. Only 16mm.

CRT video projectors always suffered from low contrast, gradually improving as optics were refined. Front screen projectors suffered both from flare in the lenses and reflection of room light. The reflection of room light was reduced quite a bit by the highly directional reflective screens. Rear projectors also suffered from lens flare, but reflected room light less.

Some lenses even had baffles built in to absorb tangential rays, while allowing the axial rays to go through. Digital mirror devices, with their much smaller lens apertures, had much less flare than CRT projectors, but also had a minimum reflectance that decreased contrast. This was improved with later chip designs.