why 160?

[johnnydc]

Just out of curiosity, anyone have any idea when/why 160 was adopted as the "standard" speed for professional color negative films?

Thanks.

[Andrew O'Neill]

I've never heard of that...what if I am using a 100 speed film or a slower one for that matter?

[Frank Petronio]

I dunno but most people shoot 160 color neg at 100 because Kodak was a little optimistic and Fuji was a copycat.

[Michael Gudzinowicz]

The film was Kodak VPS which was available in every "pro" format including 70mm bulk rolls for "school" cameras.

[Scott Davis]

It might also have something to do with a relationship to Tri-X, which traditionally was a 320 speed film. 160 is one stop slower than Tri-X, which made it easy to adjust exposure settings when switching between films.

[johnnydc]

I dunno but most people shoot 160 color neg at 100 because Kodak was a little optimistic and Fuji was a copycat.

I know, I usually shoot at 125 or 100, depending on where I want the curve. I was just wondering why so many "pro" films were OEM rated at 160.

It might also have something to do with a relationship to Tri-X, which traditionally was a 320 speed film. 160 is one stop slower than Tri-X, which made it easy to adjust exposure settings when switching between films.

So does that mean that TXP is closer to the "original" Tri-X than the TX?

[Scott Davis]

So does that mean that TXP is closer to the "original" Tri-X than the TX?

Yes. At least as far as film speed is concerned. You'd have to ask Ron Mowrey over on APUG about it (hes a Kodak engineer) as to the exact distinctions. There may be no real difference between TX and TXP, but one is labelled as 320 and the other 400 (we're talking less than 1/2 stop film speed between them, so there's no qualitative difference there). It might just be a similar kind of difference between "Pro" and "amateur" color films, where the amateurs are shipped "unripe".

[Oren Grad]

There may be no real difference between TX and TXP, but one is labelled as 320 and the other 400 (we're talking less than 1/2 stop film speed between them, so there's no qualitative difference there). It might just be a similar kind of difference between "Pro" and "amateur" color films, where the amateurs are shipped "unripe".

TX and TXP/TXT are completely different films, with radically different tonal characteristics. The marketing decision to call them both "Tri-X" was really perverse.

[johnnydc]

TX and TXP/TXT are completely different films, with radically different tonal characteristics. The marketing decision to call them both "Tri-X" was really perverse.

My understanding is that Tri-X was more a product line than a single product, similar to the T-Max name. I have an old Kodak Databook that lists a number of Tri-X films, including Tri-X Ortho.

[Oren Grad]

My understanding is that Tri-X was more a product line than a single product, similar to the T-Max name. I have an old Kodak Databook that lists a number of Tri-X films, including Tri-X Ortho.

This is true. But while there is little confusion about the fact that TMax 100, 400 and P3200 are different films - perhaps because of the different speeds - the TX vs TXP (and previously TXT) distinction causes no end of trouble. It's not just on discussion boards - most of the camera store salespeople I've encountered over the years haven't understand the difference either, and have been baffled as to why Kodak should have two films, both named "Tri-X", with speeds that are almost the same.