Complete Guide to 70mm Film

MCB18 said:

I’m not sure how to send the STL files here, I’ll see if I can figure out a way to upload them somwhere public, but in the meantime, I can probably send a dropbox link or something.

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Yeah, good point; we need something for this. @Sean, please take note of this; we may want to add some kind of option for photo-related file sharing that's not image files.

@MCB18 thanks for offering to share the design of the 65/70mm reels for 2500 tanks. A couple of questions:

1) Which filament material did you use for the print? Are there any lock between the top and bottom parts?
2) How easy and difficult to thread the negative from center, compared to stainless steel reels?

blee1996 said:

@MCB18 thanks for offering to share the design of the 65/70mm reels for 2500 tanks. A couple of questions:

1) Which filament material did you use for the print? Are there any lock between the top and bottom parts?
2) How easy and difficult to thread the negative from center, compared to stainless steel reels?

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So, just to be clear, I have not actually printed this model yet, but it is very similar to the spiral I have printed for 70 mm (which should be somewhere further back on the thread, but I’ll see if I can find the pictures).

The difference is are that the central hole is a little bit bigger, and the pitch of the spiral is a bit shorter just so that it can fit in the 2500 tank.

As far as your questions:

I had that spool printed at my school, at the time ABS was loaded in the printer, so that’s what they used, although I’m fairly certain that you can use other less annoying to print filaments if you wish. The top and bottom are keyed, so they will fit together correctly, but you do need to glue them.

Loading the film was a bit tricky with the spool I did print, but that’s because I didn’t make the grooves the film went in deep enough. I have since made them deeper, and although I haven’t had a chance to get the revised version printed myself, I do know someone else that has printed it and it worked well for them.

If you can load a stainless steel reel, you can probably load this reel just fine. And if you have ever loaded one of those Ilford 72 exposure plastic reels, this will be a piece of cake.

Currently working on a 65mm back for the RB67, it will take 100 ft loads of 65mm film and make approximately 300 51x71mm images on that roll. I am going to see about making an automatic frame advance lockout, but that might end up being too complex for me.

I am also trying to make it compatible with 15 ft cassettes, by way of an adapter, but that may also be rather complex. We’ll see.

That's going to be massive
I need to see that

Save file corrupted so now I gotta start over, big sigh.

MCB18 said:

Save file corrupted so now I gotta start over, big sigh.

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In Fusion?? That's usually a Solidworks trick.

markaudacity said:

In Fusion?? That's usually a Solidworks trick.

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lol, CAD things.

So, I have a question for you guys.

I am breaking up part of a roll of 2424 into 120 for a friend since they don’t have a 70 mm back. I was splitting the roll up so that I could slit part of it to 61.5mm in one big section, however, when I measured the two rolls of film that I got, just as a sanity check, they added up to about 162’ (49.5 m).

On the can, and in the specs that Kodak provides, it says there’s 150’ (45.7m) of 70 mm film without a leader or trailer. That’s a good 4m discrepancy.

So, I’m wondering now, even though Kodak says that there is no leader/trailer in the spec, do they still add extra film to these rolls? Has that been a thing that they always have done?

Definitely a niche question, and won’t actually affect anything, but I thought it was curious enough to ask here and see if anyone knew.

MCB18 said:

So, I have a question for you guys.

I am breaking up part of a roll of 2424 into 120 for a friend since they don’t have a 70 mm back. I was splitting the roll up so that I could slit part of it to 61.5mm in one big section, however, when I measured the two rolls of film that I got, just as a sanity check, they added up to about 162’ (49.5 m).

On the can, and in the specs that Kodak provides, it says there’s 150’ (45.7m) of 70 mm film without a leader or trailer. That’s a good 4m discrepancy.

So, I’m wondering now, even though Kodak says that there is no leader/trailer in the spec, do they still add extra film to these rolls? Has that been a thing that they always have done?

Definitely a niche question, and won’t actually affect anything, but I thought it was curious enough to ask here and see if anyone knew.

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Not a firm answer, but I do know Kodak's 100' reels of 16mm and formerly produced double 8mm film are 'long' to make up for leader & trailer use / burned film. Historically, 16mm film had non-film leaders. Also, the lead film was Kodak's to do with as they please in processing cuts / splices. Maybe they do the same here.

Sonynolta User said:

Not a firm answer, but I do know Kodak's 100' reels of 16mm and formerly produced double 8mm film are 'long' to make up for leader & trailer use / burned film. Historically, 16mm film had non-film leaders. Also, the lead film was Kodak's to do with as they please in processing cuts / splices. Maybe they do the same here.

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And that is a great point! Looking at SP 445 (the current 16mm camera spool offering), it is noted to have integrated leader/trailer. SP 494 is specifically noted to not have such length, which is why it surprised me.

This had me curious, so I looked up a few of my other specs. Most don’t have extra film, but one, SP 475, does! Which interestingly means that the 150’ rolls of techpan that @OrientPoint sold could have some extra film as well!

MCB18 said:

On the can, and in the specs that Kodak provides, it says there’s 150’ (45.7m) of 70 mm film without a leader or trailer. That’s a good 4m discrepancy.

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I'll have 0.5m left over from my bulk 70mm Konica-Minolta color roll by the time I finish it. It's my first ever bulk film and I made a jig to roll out enough film for a 116 each time, very close to a meter. The bulk roll is 100ft = 30.5mts non perforated, so 30 full films + a half a film.

I can't find this in the search (unbelievable!)...there's no discussion of who makes Murnau and Dziga and the other emulsions available from Mercury. Astrum?
Enquiring minds...

Dr. no said:

I can't find this in the search (unbelievable!)...there's no discussion of who makes Murnau and Dziga and the other emulsions available from Mercury. Astrum?
Enquiring minds...

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Yeah, they’re films cut by Astrum. Aviphot and Tasma emulsions.

Also, the NDT (non-destructive testing) reels that are repeatedly mentioned are for x-ray film...anybody seen any 70mm xr film lately?

Dr. no said:

Also, the NDT (non-destructive testing) reels that are repeatedly mentioned are for x-ray film...anybody seen any 70mm xr film lately?

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I know where to get it, but I don’t have the cash. It’s something like $900 for 1000 ft. I have thought about buying some on eBay to see what it’s like and possibly get a group buy going, but never ended up doing that.

Edit: looking on eBay, there’s a box of 100 4.5x10” sheets for $130 after tax, I could absolutely make some 10 inch long 120 rolls if folks wanted me to. I might give that some thought…

MCB18 said:

I know where to get it, but I don’t have the cash. It’s something like $900 for 1000 ft. I have thought about buying some on eBay to see what it’s like and possibly get a group buy going, but never ended up doing that.

Edit: looking on eBay, there’s a box of 100 4.5x10” sheets for $130 after tax, I could absolutely make some 10 inch long 120 rolls if folks wanted me to. I might give that some thought…

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So you'd get like 3 images per roll with a 67 system?

I'm curious but I can't seem to find any example images of Agfa D4.

There's a 100 pack for $57 with shipping if you don't mind 15 year old expired film

lt_col_gordon_tall said:

So you'd get like 3 images per roll with a 67 system?

I'm curious but I can't seem to find any example images of Agfa D4.

There's a 100 pack for $57 with shipping if you don't mind 15 year old expired film

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I was told not to bother with this stuff if the plan is to use it in rollfilm cameras. Apparently it’s on a really thick sheet base, thicker than normal sheet film. Which makes me not super interested in pursuing this more.

I do have some 70 mm film that’s on sheet base, and it will technically fit on a 120 spool, but it does not make my camera very happy…