Slitting film precisely (lengthwise)

[David Lyga]

Slitting film precisely (lengthwise)
There are people who cut film down to the format they cannot easily buy (ie, 120 down to 127, 35mm down to Minox). How can this be done most effectively in the dark with precision and no scratches? I am confident that there are alternate ways of doing this and I am presenting this question in the hopes of finding out alternatives.

 

[keithwms]

I am thinking of trying the following: wrap the film around a cardboard core, then wrap a foot or two of black paper around it and tape it so that it's really held firm. Cap the ends to prevent light leaks. Then use a saw or guillotine...

I have 5" roll film and have been thinking of modifying an office shredder for this purpose as well. If a few of the knives could be removed and the passageway covered with a nonscratch surface....

 

[frobozz]

The sawing or guillotining would still have to be done in the dark after all that, since the newly cut edges would be exposed to light.

Duncan

 

[Simon R Galley]

Dear Keith,

Whilst a great supporter of individual efforts and innovation....slitting film is something you really should not
try to do.

Apart from the fact its not easy slit, the action of slitting film in the way you describe would 'stress' the film which would be apparent on processing, you would also introduce masses of static which would attract the significant amount of debrise that your cutting device would generate.

Simon. ILFORD Photo / HARMAN technology Limited :

 

[Nicholas Lindan]

slitting film is something you really should not
try to do.

Absolutely - that's why it is so important that film makers supply 127 and Minox and 116 and 122 and ... and respooling is a bad idea too, so add 620 and 616 and ... [insert smiley if needed]

 

[Nicholas Lindan]

Until Ilford can get production ramped up: Most film slitters are made by the Minox shooters:

http://kcbx.net/~mhd/2photo/slitter/build.htm
http://www.subclub.org/darkroom/splitter.htm
http://photo.net/minox-camera-forum/004PvV

But I am sure the plans can be expanded to making 127 from 120. Not so sure about making 122 and larger from aero film.

Google for more.

 

[jamie young]

Slitting and cutting film is problematic because of dust and stress. I've done it with film for cirkut cameras, knowing i would lose a little of the edge, which wasn't a problem. Also the cirkut film moves past a felt surface before exposure naturally cleaning dust. I've used the same method for a swing lense camera with out the moving film and had more problems with dust. I'm working on a slitting jig to cut aerial film to 7" and other widths.
Simon With respect,it's easy to recommend not cutting and slitting one's film even though there are NO other sources of that film size. What other solution does this person have. My question to you is
What can Ilford do to help fill the void of these missing film sizes in a way that is viable to the consumer AND profitable and therefore worthwhile for ilford. I use odd size cameras and would like to find sources for these formats. It would be great to find a source for 16" and 7" and 6 1/2" film on a 120 thickness base. When does it become worthwhile for Ilford to make a special size film. What are the parameters that you go by to figure that out, as each film size would have it's own problems. I would find it helpful to have a sense of what you company looks at when figuring this out. I would guess that it would be a minimum amount or length of film from a master roll, then the amount of cuts of that amount, and then packaging costs.
Best, Jamie young

 

[Worker 11811]

How to turn a disposable 35mm instamatic camera into a film slitter:

http://www.instructables.com/id/Instamatic_Film_Slitter/

 

[Simon R Galley]

I do appreciate the issues.

We would love to 'customise' slitting, but it is just not economic, we do try and do our bit with all the ultra large format slitting we do once per annum.

Its not even the cutting, its usually the waste and packaging that makes it a no go....

Sorry

Simon. ILFORD Photo / HARMAN technology Limited :

 

[keithwms]

The sawing or guillotining would still have to be done in the dark after all that, since the newly cut edges would be exposed to light.

Duncan

True, but you could set up the job in room light.

P.S. I have a diamond wire saw, that would probably be the best way to go.

 

[keithwms]

slitting film is something you really should not
try to do.

Thanks for the inspiration Simon, I will certainly do it now. I've made a pretty good career of "shouldn't dos."

 

[Robert Hall]

A long while back I remember on the infrared mailing list that someone had made a channel that would route 70mm IR film through with 2 razor blades set at the appropriate distance for 120 and would essentially drag the film through the cutter. He had the length setup on rollers and was able to do a 400 ft spool. He would replace the blades after each run. If I can find the conversation or a reference I will post it.

 

[frobozz]

Yes, 70mm-to-120 seems like an obvious need, and that format that is still largely supported! It's not just the 127/626/Minox/etc. folks who find the need to slit film.

Duncan

 

[jamie young]

Simon It's great Ilford does the ulf run. Really is, and we're lucky to have that. Thank you

On this matter, it seems odd that there isn't a point where it becomes profitable and worthwhile to do an order like this, though it may not be viable to the consumer. If one pays for feet off the master roll, or whatever roll you cut from, waste and all. Then time on cutting machine costs dollars. Putting roll of film in whatever light tight box it fits in (for me anything would do) (z) dollars
Markup for profit to ilford (a) dollars. Put it all together. An understanding that as a special order handling of the film on my end is my issue goes with this. Of course this figure may be higher than I can justify, but it would be great to know generally what it is

 

[Simon R Galley]

Dear Keithwms,

Go for it ! : let me know how you get on...I have a sneaky feeling you may succeed....

Simon. ILFORD Photo / HARMAN technology Limited :

 

[Simon R Galley]

Dear Jamie,

It is not as simple as that, if you ignore the volumes and the actual sales process, with different film widths its lots of things, specific automated machines, spools, backing strips, edge writers, packaging, from master reel ( parent roll ) to finished product it really is a very complicated manufacturing process.

The answer is yes we could do it, but the cost for anything other than 35mm / 120 film and sheet film would be prohibitive to teh end user.

Hope that helps

Simon. ILFORD Photo / HARMAN technology limited :

 

[AgX]

Simon,

Aren't over-complicating things at some aspects?
Not all types need backing papers, not all users need edge signing. Some users maybe content with just-slit long rolls.

 

[Reinhold]

Simon,

Any possibility of purchasing a pre-slit roll of FP4 (120 size) so that those of us who are whining over the loss of 220 film could re-spool it ourselves?

I saved a bunch of the "tops and tails", as you folks call the paper leader and wrapper, and I'm confident that I could make some more from existing 120 wrappers if need be.

I would have no problem cutting the film to length and assembling it with leaders...

I'm assuming that you pre-slit the log (parent roll) down to 120 width rolls which are then loaded into the 120 finishing lines. Any possibility of purchasing one of those rolls??? How long are they (what diameter?)?

I realize that that would impact the sale of 120 film, so you'd need to price a roll accordingly... (ouch)... but it might be worth it to some of us who really miss 220 film.

Best regards

Reinhold

www.classicBWpnoto.com

 

[frobozz]

Isn't 220 also thinner base stock than 120? Or am I just confused?

Duncan

 

[Reinhold]

Duncan,

It's the same stuff. Ilford, Kodak, and Fuji 120 and 220 films all measure within 0.0005" thickness of each other.

Reinhold

www.classicBWphoto.com

 

[frobozz]

Huh, OK. I had some older 220 film I shot and I was annoyed by how thin the film base stock was, so decided to just stick with 120 instead. Now I need to go dig that up and figure out what was really going on...

Duncan

 

[Reinhold]

Duncan,

A couple of thoughts...

It's been a while since I measured film thickness, there's no guarantee that base stock changed over time.
Acetate based film has a different "feel" than polyester based film.
I have the older 4-1/4 inch diameter 220 reels which are much easier to load than the narrow wire 3-1/4 inch reels.

220 is about twice as long as 120 film (±64 inches), getting all that film onto the same size spool means that it must be tightly wound to start. If necessary, one could spool a few inches short (say only enough for eighteen 6x7 frames). It would still be a hekkuva lot better than fiddling with two 120 spools...

Reinhold

www.classicBWphoto.com

 

[ishutteratthethought]

I have been getting my Minox cartridges reloaded at Goathill http://www.subclub.org/sponsors/goathil2.htm
This is great place to get hard to find film sizes. They sell slitters as well.
The reloads I have been getting there have been pretty good considering the process. Some parts on the rolls have scratches. Doesn't bother me too much especially when I am shooting with the Minox and printing with lith.
Steve

 

[Kirk Keyes]

Perhaps Ilford could make group order of bulk rolls for Minox film and then the end user would be responsible for loading it into reels. Use the same cannisters and bagging as 35mm, and all that would need to be customized for packaging would be the spools.

 

[mgb74]

I'm going to go not so far out on a limb here and say that if Ilford thought slitting and selling odd sizes of packaged film met their profit objectives, they would do so. Fixed costs and overhead often make the difference. What could possibly work is selling slit film in bulk to an intermediary, with a different cost structure and perhaps private labeling. Analogous to Freestyle's Arista Premium.