How many film factories?

[tomalophicon]

I have no idea. But I can show you a photo from a Zebra factory.

Genius.

 

[cmacd123]

I guess I don't get you on this. You say 29 rolls of 6000 ft?

PE

Did I calculate wrong? 40 usable inches is (42*25.4) or 1016mm, divide into 35mm chunks and you get 29. I had always heard that it was more like 32 or 36 strips.

A mile is about 5000 and some feet, and I know that the motion picture print film comes on 6000 ft rolls so I am guessing that is what you mean by a miles worth.

Still a lot of Tri-X

 

[Photo Engineer]

Just a senior moment on my part.

That is a lot of film. But, you have to consider defects at about 10% and mapping around those defects in order to make defect free film rolls and sheets.

PE

 

[Christiaan Phleger]

OK PE, how do they map around the defects and how they Found the defects in the first place.

 

[Photo Engineer]

At Kodak, film is scanned by an IR device that maps defects over 100% of the film surface. This goes into a computer program which then calculates the optimum slitting and chopping matrix for that product as for example 35mm 24 exp, 36 exp or disposable camera, and 120, 220 if that is the case or 4x5, 5x7 or 8x10 if that is the case. Each of these are based upon the respective supports used for the films in question.

Its that simple.

I'm surprised you didn't figure that out yourself!

PE

 

[tomalophicon]

How did they scan the infra-red film (and I'm too dumb to try to figure it out on my own)?

 

[Christiaan Phleger]

Well, I had an idea it was IR. Now I am sure.

 

[Simon R Galley]

It is indeed IR:

We use 'presumably' the same system ( INTEC ) the computer map it produces is logged to the individual roll ticket with matching bar codes, and when the finishing department come to finish the roll they bring up the 'map'. As PE says on a film parent roll waste is between 7% and 10% including 'Patterning'. We finish each parent roll to only one format, as roll film and sheet film are on different film bases.

Simon. ILFORD Photo / HARMAN technology Limited :

 

[Photo Engineer]

There is long and short IR, as well as "windows" in the sensitivity of film. These can be used to allow scanning for defects. But, that difficulty with IR is one reason why IR film is so expensive.

PE