How wide is 70mm film really?

frobozz · Apr 27, 2010

I know this sounds like a stupid question, since it's supposed to be 70mm wide... but 120 film is supposed to be 60mm wide, and all the stuff I have measures more like 61-62mm. Anyone have any 70mm film in their hands, along with a good measuring instrument? I've looked high and low with google and can't find a spec on this, other than some ISO specs that cost a million dollars to download. I was hoping for a Kodak tech pub somewhere, but I can't come up with one, probably because that kind of thing was settled so long ago and everyone (except me) just knows the answer by now.

Thanks,
Duncan

Prarry · Apr 27, 2010

I have transparencies from a Ferrari press kit from a few years ago on 70mm. And, yes it is 70mm wide, measured by eye using a steel engineer's rule - looks spot on the measure as far as I can see.
Why?

keithwms · Apr 27, 2010

I could be wrong but I think the 70mm width was originally meant to be double perfed.... so, same image area as 120/220, but with sprockets on both sides.

frobozz · Apr 27, 2010

Goat Hill Photo is willing to make me a slitter, in case I ever again run across some of the deals I've previously passed up on interesting 70mm film, so I could cut it down to 120 size. I thought it would be easy to tell them "cut the center 60mm out of a 70mm width" but then I was thrown when I measured some 120 film just to be sure, and it was wider! So I wanted to make sure about the 70mm part too, and I don't currently have any of that in hand.

The idea behind the center cut is of course then I could use perfed or unperfed film and it would work equally well. Even if there were some tiny "dents" along the edges, it should be out of the imaging area of my 645 camera.

Duncan

Prarry · Apr 27, 2010

Sorry, rubbish scan of old transparency in a very dusty sleeve. I can make a better scan this evening and send it to you as an image. It is 70mm double perforated. Was a common format for reproductions from studio shots (medium format) when larger numbers of copies were needed.
Never actually ‘met’ 70mm in any other context.

(there was a url link here which no longer exists)

Worker 11811 · Apr 27, 2010

The only 70mm film I have is cinema film. Yes, 70mm cinema film is 70mm wide but there is something called "70mm camera film" used in the movie cameras, themselves, which is actually only 65mm wide.

The reason is that 70mm release prints have (or had) magnetic soundtracks printed on the edges and, therefore, needed that extra 5mm to hold the mag stripe. Camera film doesn't need the mag stripes.

So you could suppose that those who are using "70mm" film in their cameras for still pictures could be using something made off the 65mm pattern for movie camera film or even be using actual 65mm cinema film.

frobozz · Apr 27, 2010

Right, the 65mm film thing could be a confounding factor, but so far all of my (passed-up) opportunities for 70mm film have just been regular long rolls of 70mm still camera film, so they should be nominally 70mm-or-whatever-it-is.

Anyone know why 60mm film is really a mm or two wider? I'm sure there's a story there...

Prarry - Oh! After seeing your scan, I just thought of something else that would be nice to know, since you have some actual double-perf film in your hands. What is the precise distance between the insides of the sprocket holes? In other words, do I have 61 or 62mm of untouched film down the center? Or are my 120 rolls going to have bumpy edges from the remnants of sprocket holes?

Thanks,
Duncan

Q.G. · Apr 27, 2010

frobozz said:
Anyone know why 60mm film is really a mm or two wider? I'm sure there's a story there...

But is there a film called "60 mm film"?
I know of a negative format that is 60 mm, though only nominally.
But a film called "60 mm film"?

frobozz · Apr 27, 2010

No, of course 120-family roll film is not officially referred to as 60mm film, but I have seen it casually referred to as 6cm film. It's just weird that it's close but not really.

Duncan

Prarry · Apr 27, 2010

Width between the sprocket holes is exactly 60mm, right up to the edge of the holes. The image area on the one I brought home is 54 x 82mm. Edge marking is K'ODAK 2071 (yes with the apostrophe). All I can find.

frobozz · Apr 27, 2010

OK, thanks! I now know pretty much everything I wanted to find out, but without paying thousands for the official spec

So it looks like I'd have bumpy edges on my slit film, but I can't really think of any downside to that other than looking weird. Might make loading it in a stainless reel more exciting than usual, but not unworkable. Though of course starting with unperfed film would work even better.

Duncan

Mike Wilde · Apr 27, 2010

I have a roll of 100' of 70mm unperfed Portra 160NC that came from what used to be fed into long roll school portait cameras in the freezer.

I have cut off abouta dozen 120 lengths os far, slit it to 61mm, and reloaed it onto backing paper. It is a pain in the ass. There are still other film options open to me for 120/220 before I go and do it again.

I am now thinking about making a custom adapted double cut film holder and shooting 70mm x 5" panorama like copur landscapes in my 4x5 camera.

5stringdeath · Apr 27, 2010

They make a 70mm back for the Bronica ETR series ... I always wondered what it was for ... probably can't fill it with anything these days.

Sirius Glass · Apr 27, 2010

More important than the width of 70 mm film is what is the size of the exposed negative in your camera?

Steve

keithwms · Apr 27, 2010

Sirius Glass said:
More important than the width of 70 mm film is what is the size of the exposed negative in your camera?

Steve

???

He wants to slit larger film...

Bwright · Aug 15, 2010

What I want to know, if anyone can help me, is if you can spool the 65mm movie neg without paper? I know the remjet backing blocks light for daylight camera loading of 16mm spools, but when I hold my ecn2 film on the light table I have to double it up for no light pass through.

And does anyone know of a resource to get Vision3 in 65mm bulk for me to cut down and spool as 220? I don't care about the perfs, cuz actual image projection is only like 56mm. Thanks!

frobozz · Aug 16, 2010

What blocks the light for daylight loading of a movie camera is the spool itself, not the remjet. While threading a movie camera, all of the film that's off the spool is light-struck, and if you're not careful in bright light conditions, the edges of a few turns down into the spool will also be light-struck. Then the bulk of the film is in the dark inside the camera when being exposed... and then the last turn or two on the end is ruined when you unload it. If you want to turn 65mm film into 120/220 film you're going to need to transfer it in the darkness to a spool with a paper backing. I think you're also going to have to trim a few mm off of the 65mm!

Duncan

trendland · Apr 23, 2017

frobozz said:
I know this sounds like a stupid question, since it's supposed to be 70mm wide... but 120 film is supposed to be 60mm wide, and all the stuff I have measures more like 61-62mm. Anyone have any 70mm film in their hands, along with a good measuring instrument? I've looked high and low with google and can't find a spec on this, other than some ISO specs that cost a million dollars to download. I was hoping for a Kodak tech pub somewhere, but I can't come up with one, probably because that kind of thing was settled so long ago and everyone (except me) just knows the answer by now.

Thanks,
Duncan

I have an original IMAX Cine Copy film
the film as a slide witch was in a cinema projektion originally.

It is double - perforated as normaly and
It has the exact wide of medium format still film.

So 70mm film is the same as still film
6x7, 6x9.

Found a side (wikipedia) they also say
"70mm Cine film format is in the same format used with still film cameras"

But now I am not as sure as in the last 20 years.

Looking to my IMAX - realizing that it is as good archieved as I can't find it now.

But I am sure it is the same hight and of cause IMEX CINEMA should be 70mm
Film - or is it not ?

Being confused

with regards

flavio81 · Apr 23, 2017

Worker 11811 said:
The only 70mm film I have is cinema film. Yes, 70mm cinema film is 70mm wide but there is something called "70mm camera film" used in the movie cameras, themselves, which is actually only 65mm wide.

The reason is that 70mm release prints have (or had) magnetic soundtracks printed on the edges and, therefore, needed that extra 5mm to hold the mag stripe. Camera film doesn't need the mag stripes.

So you could suppose that those who are using "70mm" film in their cameras for still pictures could be using something made off the 65mm pattern for movie camera film or even be using actual 65mm cinema film.

Film for 70mm still camera backs IS supposed to be 70mm wide, perforated, so the usable area is similar to 120 film. So 70mm film for STILL CAMERA is 70mm.

On "70mm cinema", the MOVIE CAMERA films are 65mm wide, and the RELEASE prints are 70mm wide. (The release prints used to have magnetic sound strips, thus the need for wider film.

This means, cameras for the big "70mm" movie format are 65mm cameras. For example, the ARRIFLEX 765. Here the "65" is making reference to the 65mm film.

@trendland so the quote that says "70mm Cine film format is in the same format used with still film cameras" perhaps means that the RELEASE 70mm movie film has the same format as the STILL CAMERA 70mm film. This would be true if the perforations' are the same (same dimensions, spacing, etc.)

AgX · Apr 23, 2017

flavio81 said:
Film for 70mm still camera backs IS supposed to be 70mm wide, perforated, so the usable area is similar to 120 film. So 70mm film for STILL CAMERA is 70mm.

On "70mm cinema", the MOVIE CAMERA films are 65mm wide, and the RELEASE prints are 70mm wide. (The release prints used to have magnetic sound strips, thus the need for wider film.

70mm cine print film and 70mm still film are not interchangable.
Due to the tracks and, more important, due to the perforation location.

trendland · Apr 23, 2017

flavio81 said:
Film for 70mm still camera backs IS supposed to be 70mm wide, perforated, so the usable area is similar to 120 film. So 70mm film for STILL CAMERA is 70mm.

On "70mm cinema", the MOVIE CAMERA films are 65mm wide, and the RELEASE prints are 70mm wide. (The release prints used to have magnetic sound strips, thus the need for wider film.

This means, cameras for the big "70mm" movie format are 65mm cameras. For example, the ARRIFLEX 765. Here the "65" is making reference to the 65mm film.

@trendland so the quote that says "70mm Cine film format is in the same format used with still film cameras" perhaps means that the RELEASE 70mm movie film has the same format as the STILL CAMERA 70mm film. This would be true if the perforations' are the same (same dimensions, spacing, etc.)

Yes - indeed I am not as sure about than
I was 2 days ago?
KODAk does have 70mm film in there price list - never saw this stuff before.

Doubt they name it 70mm - but this is not realistic.

It is not often in use of cause.
Q. Tarantino was the last I heard who
need it for copys of "Hatefull 8" and this
should should have been " real 70mm"
because he asembled 30 years old projektores for some cameras to make
70mm presentations of "Hatefull 8"
I have to find my IMAX - it could be that
new technology for cinemas use normal
65mm for IMAX for example because since 1993 there is no need for the
"light - sound" in the filmcopy.
It has had max.2-4 sound tracks on the
film - not enough to modern formats.

So may be there are 2 versions of 70mm.
The originally "old one" with exact 70mm - and the second "modern type"
70mm named but with normal 65mm film without "light sound" because thinking of the filmsquere it is the same.

And perhaps that is the reason of 70mm
I know as realistic 65mm witch is definitive comparable to midt format
still film.

with regards

trendland · Apr 23, 2017

AgX said:
70mm cine print film and 70mm still film are not interchangable.
Due to the tracks and, more important, due to the perforation location.

You might be wright Agx because I failse.

First let's Check the facts again.

Confusion :-(

Mr Bill · Apr 23, 2017

flavio81 said:
Film for 70mm still camera backs IS supposed to be 70mm wide, perforated, so the usable area is similar to 120 film. So 70mm film for STILL CAMERA is 70mm.

Yep, on the width of the film.

But regarding perfs, probably the majority of 70mm still camera film was NOT perforated. I say this from my experience: in the US, at least, the great majority of school and other mass market portraits were once shot on specialized long-roll portrait cameras. The "long rolls" were typically 100-ft, and there were several standard widths, including 70mm. At the outfit where I worked, we once used to process miles of 70mm film every day. And yes, it measured 70mm wide (within the ANSI tolerance), and it was not perforated.

I think this sort of thing was largely unknown in the general professional photography world, probably because it was never marketed in that direction. But certainly huge quantities of such films were used. I don't know about the specs on motion picture films.

MattKing · Apr 23, 2017

This thread highlights the problem with defining a film size by a particular measurement. This is most likely the reason that many film sizes were assigned arbitrary numeric codes.
Film (actually image) formats - it makes sense to describe them using dimensions.

AgX · Apr 24, 2017

trendland said:
You might be wright Agx because I failse.

I am right.

How wide is 70mm film really?

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