Some so-called knowledgeable institutions even call the ratio 1.25:1. No justification for the ratio, it is just how they know it.

I was reading Mr. Norwoods FAQ paper (nice job in general, btw) and he states the silent projection aperture is .94" x .71". I want to know where those dimensions came from.

The BKSTS lists it as .680" by .910"

Well, I was bound to get to the bottom of this since I know you can project above .680" on just about every silent film I have had my hands on.

I friend of mine is a big film equipment collector, Louis DiCrescenzo, who happens to have a floor at the museum of the moving image in NY for a part of his collection. I asked him if I could measure some of the projection apertures of the equipment of the silent era and he ponyed up a few examples...

They were Powers (two different models) a Simplex Regular and one other whose name escapes me.

According the callipers, all of the projectors had approximately the same dimensions within a couple thousands of an inch...with the exception of the Simplex Regular, they were fixed apertures no plates)

The dimensions were:

.680" x .910"

The BKSTS was right. Thses machines were of the Silent era, that is the area the audience saw back then and is reasonable that that is the image area the cameraman and director wanted shown.

To show a larger aperture (to show the entire picture) would be like taking a 1.85:1 picture of today and putting in the 1.37:1 plate and lens in the name of not cropping.

Steve