Kodak films narrower than others?

[Chadinko]

I've been making my own negative carriers for my 120 film (and 616, and other stuff too) for my scanner, and I've noticed that the Kodak films are about half a millimeter narrower than other films. Slightly less than that with the Delta 3200, but with Hp5 and Fomapan the difference is noticeable.

Has anyone else noticed this?

 

[Neal]

Dear Chadinko,

The target width for 120 film is 61mm. As it doesn't have to be registered to a position in the camera the way sprocket driven film is I'm sure there is variation from machine to machine. The last negative carrier I made for my enlarger can accommodate up to 63mm but I'm sure if you stay with 62mm you'll be fine. My little scribbled notes from when I made the negative carrier had measurements of 61.08mm on the low side and 61.28mm on the high. I have no correlation by manufacturer for you. You might be able to get away with 61-1/2mm but a little extra room can't hurt.

Good luck,

Neal Wydra

 

[StoneNYC]

I've been making my own negative carriers for my 120 film (and 616, and other stuff too) for my scanner, and I've noticed that the Kodak films are about half a millimeter narrower than other films. Slightly less than that with the Delta 3200, but with Hp5 and Fomapan the difference is noticeable.

Has anyone else noticed this?

They also curl more, so you may be experiencing the difference because of the film not laying as flat.

 

[Tor-Einar Jarnbjo]

The physical dimensions of the 120 film are specified in the ISO 732 standard. The film itself shall be between 60.7mm and 61.7mm wide.

 

[Chadinko]

They also curl more, so you may be experiencing the difference because of the film not laying as flat.

No... if I put two pieces of film under a sheet of glass they're very flat and still different in width. I'm thinking Tor-Einar's quote of the ISO standards makes sense; there's a little play there. Maybe Kodak's is narrower as a holdover from the failed attempt to co-opt the 120 format (as 620)? Hmmm.

 

[MattKing]

Maybe Kodak's is narrower as a holdover from the failed attempt to co-opt the 120 format (as 620)?

Don't think so, given that the film and backing paper is the same size for both 120 and 620.

 

[Chadinko]

Don't think so, given that the film and backing paper is the same size for both 120 and 620.

Except the films in question are on the average, in my stash, about half a millimeter narrower than Ilford or Fomapan. Again, I haven't checked it against all the 120s I have, but the Kodak is noticeably narrower.

 

[AgX]

We all know that Kodak had to slim down...

 

[Gerald C Koch]

If film did not conform to the ISO specification it would have an adverse effect on using reels particularly SS ones.

 

[Mr Bill]

If film did not conform to the ISO specification it would have an adverse effect on using reels particularly SS ones.

Even more significant (?), depending who you are, is the effect on all the mini-lab printers out there. If the film guides are set too narrow, they'll scrape debris from the edges of the film; if set too wide, the film will wander. (Wandering film means that the photofinisher may scan off the edge of the image occasionally, so the solution is to "over-project" more at the printing stage.)

As I recall, the typical routine for such width specs is to give a dimension, setting tolerance as plus zero, minus = some acceptable value. So if the photofinisher sets film guides just over the spec, they will never get any film that "doesn't quite fit."

 

[AgX]

A alternative is to use spring-loaded lateral guides.

 

[Sirius Glass]

Kodak films are within the specifications. That is why they neither fall out of reels nor are they too wide for reels.

 

[Mr Bill]

A alternative is to use spring-loaded lateral guides.

Sure, but then edge-rubbing always happens, as opposed to intermittently. We used to use a spring-loaded setop, with rollers on both sides, where we needed to make sure that a sensor would "see" a precisely-placed alignment mark on the edge of the film. I guess it's feasible in the printing gate, but the idea of just adding a little clearance has a lot going for it.

 

[David Lyga]

Does anyone know the exact LENGTH of 120 film (not the paper backing) ? I would guess 810mm.

 

[MattKing]

Ask me next time I have a roll hanging to dry

 

[Tor-Einar Jarnbjo]

Does anyone know the exact LENGTH of 120 film (not the paper backing) ? I would guess 810mm.

Again, according to the ISO standard: between 820mm and 850mm.

 

[David Lyga]

Thank you: I did not know that there was a variation. - David Lyga