film speed of old film

[Chan Tran]

I have an old book published by Kodak tittled "How to make good pictures". The book is copyrighted in 1943 but it's the 28th edition, 5th printing so I can't tell which year it was published. In the book they mention several Kodak films namely Verichrome, Super XX, Plus X and Panantomix X. The book didn't mention any film speed but did recommend exposure setting for them. I wonder of what film speed are those films?

 

[tessar]

If my memory serves, Verichrome was rated at 125 ASA, Super-XX at 200 ASA, Plus-X at 125 ASA and Panatomic-X at 32 ASA. Verichrome began as an orthochromatic film but became Verichrome Pan sometime in the 1950s (I think).

 

[Anscojohn]

You can tell from the exposure settings. Bright sun, f/stop 11-16--the shutter speed as recomended setting is the film speed.

 

[Chan Tran]

I asked because based on the recommended shutter speed and aperture seems like Verichrome and Plus X is rated as ISO50

 

[DWThomas]

I asked because based on the recommended shutter speed and aperture seems like Verichrome and Plus X is rated as ISO50

I think that's near correct; or at least ASA 50! I have a 1963 Dataguide, which is too new for straight Verichrome; Verichrome Pan shows as 125. It shows Panatomic X as 40 for roll film, 64 for sheets. But I seem to remember it as 32 in the late 50s. Super XX Pan is 200.

 

[mopar_guy]

Safety factors of film speeds

If I remember there was a time in the mid 1950's to early 1960's when manufacturers changed the speed ratings of some of their films by eliminating a built in safety factor. In other words, the manufacturer suggested that "overexposure" as we would expose the film now was the recommended exposure. For example, these days we rate Tri-X at ISO 400. My Photo-Lab_Index from 1946 suggests a speed for Tri-X as 200. This is a difference of one stop. If you are using an Anniversary Speed Graphic and would use the old rating of 200 you would get a little more grain, but with 3-1/4x4-1/4 or 4x5 who would notice?

 

[Jim Noel]

If the copy of "How to Make Good Pictures" is prior to the acceptance of ASA, the film speeds are Weston speeds, not ASA. Verichrome was indeed 50 in daylight, but more like 20-30 with incandescent light.(Verichrome Pan was not introduced until after ASA if my memory is correct). Super XX was 100. Since these are the only Kodak films I used extensively in the 30's and 40's they are the only speeds I remember.