Tuesday, July 3, 2018

Community question: Cutting down 120 film to 127 size - what size, exactly?

I'm delighted to share 127 Film Photography's first community question.

As noted on the Submit to 127 Film Photography page, 127 Film Photography welcomes readers' questions. All readers are invited to offer responses to the questions that are posted - let's work together as a community!

From Alessandro Lisci:

I have a question that I have not yet resolved, about the size to which I should cut 120 film. In the videos and  articles I've seen, it seems to me that the 120 film is cut to the exact size of the 127 film spool. But the original 127 film is slightly smaller than 127 backing paper (a difference on the order of 1-2mm). Doing a test with the only developing tank in my possession that has a spiral (reel) for 127 film, I realized that the measure is almost exact, and a film even slightly larger would give me problems in loading the spiral. I wonder if it's a general problem, or it's my tank that has a minimal tolerance.
- Translated by Google Translate, with editing by J. M. Golding
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Io ho un dubbio che non ho ancora risolto, a proposito della grandezza in cui tagliare il film 120. Riguarda questo: Nei filmati e negli articoli che ho visto, mi sembra che il film 120 venga tagliato alla grandezza esatta del film-spool del 127. Però  il film 127 originale, è leggermente più piccolo della carta che lo protegge dalla luce (una differenza nell'ordine di 1-2mm). Facendo una prova con l'unica tank di sviluppo in mio possesso che abbia una spirale per il film 127, mi sono accorto che la misura è praticamente esatta, e un film anche leggermente più grande mi darebbe problemi nel caricamento della spirale. Mi chiedo se sia un problema generale, o la mia tank che ha una tolleranza minima.

3 comments:

  1. So far I've tried cutting down an actual 120 film to 127 size (not just practice with backing paper only) once. I was able to load it into my adjustable Paterson Super System 4 reel without difficulty ... What are other people's thoughts and experiences?
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    Fino ad ora ho provato a tagliare una pellicola da 120 a 127 (non solo la pratica con la sola carta di supporto) una volta. Sono stato in grado di caricarlo senza problemi nella mia bobina regolabile Paterson Super System 4. Quali sono i pensieri e le esperienze degli altri?

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  2. The correct width for the backing paper is 47mm, and the film itself 46mm. I have cut down quite a lot of 120 film to 127, and from time to time there are problems, for sure.
    If the film is too wide it will jam in the developing spiral or even the spool. if too narrow, it will fall off the spiral and get in a dreadful mess.
    Not all spirals are equal though. The greatest danger is with a spiral with a shallow groove, like Jobo. The most relaxed I have found is either a Nikor stainless steel spiral (easily the best, but hard to find) or an old Johnson's Bakelite developing tank which has quite a deep and wide groove, easy to load and doesn't readily fall out. Paterson is in the middle.
    Accurate cutting is important; I haven't actually measured the tolerance but as a guide I would try not to go outside the range 45.5-46.5mm for the whole length of the film - that is, including errors of straightness as well as width. In other words if you were to draw a box on a sheet of paper 595x45.5mm and another 605x46.5mm, your film should fully cover the first and fully fit into the second. The reason is that getting a banana-shaped film into a spiral is a nightmare, even if you have the right width at every point!

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    Replies
    1. Thank you for that detailed explanation!

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