I have in my possession a photo copy 300 plus booklet called A Guide To 17.5 Sound.To be fair I don’t own any of the films nor equipment but I have reproduced the cover ,index and a couple of pages relating to the English machine for those who are interested. I am not able to copy the whole manual,but if anyone wants to see a page referred to in the index let me know.
Something a bit different.



Sorry if the image is small you will have to blow up the picture,and turn them around.

It is such a pity that the Pathescope 17.5mm sound film library closed down at the outbreak of war, and never to return.

The advantage of 17.5mm sound films is that they were full length from the originals, whereas the 9.5mm sound features were highly edited, but I believe that their last feature releases, which were on 9 reels, may have been complete. The 17.5mm sound films were only available for hire, whereas the 9.5mm sound films could be hired or purchased outright.

For those members interested in this gauge, here are some details, and comments, from the late Grahame Newnham.

http://www.pathefilm.uk/seventeen/175seventeen.htm

I started subscribing to the Amateur Cine World magazine from the Spring issue of 1946. I can still remember the ads "We can modify your 17.5mm sound projector to run 16mm sound films".

Thank you Maurice,I did wonder if there would be any response to this one I don’t suppose anyone actually still has/ runs this gauge of film but we shall see.
The catalogue of films does make for some interesting reading.

Gwyn
You can click on Martyn Stevens website. I
He collects old projectors of all gauges and might have some 17.5mm that are still used.
http://www.cinerdistan.com/2-uncategorised/397-17-5-2

I had heard of the 9.5 mm gauge, but not the 17.5! 😳 Am I missing anything else??

Tim
28mm.
https://en.wikipedia.org/wiki/28_mm_film

8mm coming after splitting a 16mm makes sense, and I guess that's the thing of 17.5 being half of 35. But I have wondered why we never saw 32 (double of 16) or 8.75 (quarter of 35). How did they go from 35mm to 16mm?

Kodak hired Willard Cook from Pathescope's 28mm division to create a new film gauge for them in 1923. The result was 16mm. At the time this new safety film was designed for amateurs.

And quite probably, with an eye for the future, in order to create a cheaper gauge of 8mm.

8mm film was supplied in 25ft lengths which were 16mm wide, after processing it was slit, and the two 25ft length now became a 50ft length of 8mm film. For convenience it could also be handled on processing equipment designed for 16mm.