Rob-F
Likes Leicas
Motion Picture Processes such as Todd-AO and Super Cinerama covered a deeply curved (120 degree) screen, using only a single projector; and held the whole screen in perfect focus. They must have used a special lens for this. My eight-foot screen is curved to a depth of less than four inches, yet I can't keep the whole screen in perfect focus all the way across with any one focus setting. I wish I could. In fact, I'd like to curve it 8 or 12 inches deep if I knew how to get it all in focus.
we have all heard of curved-field projection lenses. I have a couple of Kodak curved field (Ektanar-C) lenses. But they are meant for correcting the curvature of slides not mounted in glass. That's only a slight correction. And the cheap Kodak lenses are not nearly as good as the Golden Navitar and Schneider projection lenses I use.
I phoned Buhl Optical some years ago. They make projection lenses. They said they wouldn't be interested in developing a curved screen lens.
I wonder what the makers of lenses for curved movie screens--American Optical, Kollmorgan--did to get their lenses to focus on curved screens. And how I could.
Does anyone know anything about this?
we have all heard of curved-field projection lenses. I have a couple of Kodak curved field (Ektanar-C) lenses. But they are meant for correcting the curvature of slides not mounted in glass. That's only a slight correction. And the cheap Kodak lenses are not nearly as good as the Golden Navitar and Schneider projection lenses I use.
I phoned Buhl Optical some years ago. They make projection lenses. They said they wouldn't be interested in developing a curved screen lens.
I wonder what the makers of lenses for curved movie screens--American Optical, Kollmorgan--did to get their lenses to focus on curved screens. And how I could.
Does anyone know anything about this?
sevo
Fokutorendaburando
Cylindrical lenses. The curved screen systems generally are anamorphic - indeed they have to, to reach the desired super wide aspect ratio without getting too small even on 70mm film. And given a anamorphic system with its cylindrical lenses, all you have to do is not correct the latter to 100%, and you end up with a curved field of projection.
_goodtimez
Well-known
I have one Leica projector lens for my Pradovit with is marked CF: curved field.
This is to cope with the curvature of slides when mounted inside a frame.
It works.
This is to cope with the curvature of slides when mounted inside a frame.
It works.
Rob-F
Likes Leicas
This is correct; however, Todd-AO was not anamorphic, and still used a 120 degree curved screen. Super Panavision was also flat (non-anamorphic). So there must be another way.