Is there such a thing as large format roll film? 4x5 or 8x10 or other standard sizes

[table1349]

"A man that started in to carry a cat home by the tail was getting knowledge that was always going to be useful to him, A man that carried a cat home by the tail once has learnt sixty or seventy times as much as a person that hadn't and warn't ever going to grow dim or doubtful. For one thing, he learns never to carry a cat home by the tail again. If a man wants to carry a cat home by the tail I say let him. It's not easy to be eccentric these days." Mark Twain

 

[unpopular]

The idea was not to purchase roll/bulk film. It was to take standard LF sheet film and attach it semi-automatically at home base (i.e. with a jig to allow me to do it in darkness) to either the next sheet of film, or a polyester (or otherwise similar most likely to the film itself) substrate, which gets rolled into the feeder roll, with a leader remaining. Then lights can go on, attach to other roll, load into camera.

Ok. We've officially entered crazytown.

An 8x10" Grafmatic would super cool and far more feasible. You could 3D print the whole thing and assemble the parts in an hour. Once you fully understand how it works, you could have a basic magazine in a few weeks.

But this? This is just nutballz crazy.

 

[Derrel]

...makes my helicopter patterned after a dragonfly idea sound pretty smart...

 

[unpopular]

and my music synthesizer based on holographic interference genius!

We all spend time daydreaming, and technically minded people will daydream about technical things. Knowing when something is just that and when to take it to the next level is key.

 

[table1349]

Why do I have the feeling that this thread will some day end up here? The most stupid inventions (30 pics) - Izismile.com

I like the illuminated tires the best. :thumbup:

 

[unpopular]

it's amazing that the OP has taken a relatively simple idea that has successfully been done before: a large rollfilm format, and managed to clusterfutz it into something that would be absolutely ridiculous and never ever work.

I'm not sure what lead him to think that attaching sheet film to a polyester transport base would be a good idea. I'm guessing it was challenges involved with processing or concerns over film stock, but both issues are easier to remedy than the issues that would be created by stringing along sheets of film on a roll of polyester.

Hell, coating film with emulsion would be technically easier.

Maybe it's unpatriotic to be such a naysayer to someone's dreams on the fourth of July. But no, this latest incantation would never work.

 

[Gavjenks]

Hehe, that's okay, I didn't expect you all to give a big thumbs up.

It's going to cost me all of about $6 to test the attachment method on some throwaway pieces of film in the light, and then slide the two across a shoebox or whatever is handy to see if they can still be made flat after that, or if it warps it or something. If it works, then the whole thing will almost certainly work, and if it doesn't, I'm out $6. I'll post the results here when I get around to it, for the amusement of the peanut gallery

Note that I have successfully built a wooden laptop before and am in the process of making a homemade 4-octave pipe organ (+ 2 octaves of mineral oil immersed bubble pipes that make bubbling noises in a given pitch instead of standard flute sounds!), which so far is working fine. A homemade LF roll honestly does not sound any more crazy or difficult.

Also, if you build a roll camera, and it doesn't work well, you can always just chisel a mortise into it, etc. and use holders (I will take that into account), so as to have not wasted the whole project. I usually try to design in some way to salvage my time and effort like that for a particularly crazy project.

 

[vintagesnaps]

You're going to need some really big spools... Wouldn't you need something somewhat larger than 8" so that each frame (or in this case sheet of film) has some space around it to support/position and transport it thru a camera? I'd think the spools would need to have posts with a fairly large diameter because you probably wouldn't want the film to curl too much; and the circular ends would need to be large enough to hold a long length of film wound on it. So that would seem to add extra space that would be needed in a camera to hold the rolls of film - 12 images on a roll would be 10" (+space in between) times 12 ... that's going to be a long roll of film - if you only make it long enough for a few sheets why bother? individual sheets would seem to be more efficient.

To make prints, even putting a strip of 35mm film in a negative carrier it tends to curl enough that it doesn't lay flat til you close the carrier and sandwich it in. I would think trying to roll larger sized film would make it that much harder to keep it flat after it's exposed and developed to be able to get a good quality print from it.

Ilford just ended their annual ULF (Ultra Large Format) ordering process at the end of June (which actually includes films that aren't necessarily large format), and I don't remember offhand noticing if any rollfilms were listed, but on their site their product list includes longer rolls of film (most don't show up as being regularly in stock).

What you're describing reminds me of the Polaroid roll films, where as the photo would be pulled out of the camera it would detach from the roll and apparently self develop the way that the peel-apart film does now. I don't know offhand what size those rolls were but certainly not close to large format size.

I think with this project you might just end up finding out why sheet film is in sheets instead of rolls.

 

[Gavjenks]

Wouldn't you need something somewhat larger than 8"

Yes. Probably 9-9.5" is sufficient. And the extra 1-1.5" does not have to be housed inside the camera box necessarily.

You're going to need some really big spools..

0.007" is the thickness of film + transport medium. Or 0.004-5" if roll film is bought commercially.

For 25 shots per roll, and at minimum 1.25" inner roll diameter to avoid damage, excel calculates (using turn-by-turn calculations of increasing diameter) 1.936" final rolled up diameter. So a 2" inner diameter tube would sufficiently house a fully wound 21 foot long, 25 shot spool that started with a 1.25" outer diameter spindle. Commercially bought film would of course have more clearance than this, and would allow a narrower tube. Not bad at all.

The spindle on 35mm rolls is significantly smaller than 1.25" and the film base for LF is only about 50% thicker than 35mm film. So I think that more than doubling the diameter for 50% more thickness should be plenty sufficient to avoid damage. Though I need to test this. This is also actually thinner than I originally estimated by a lot.

And aluminum turns out to be a much better option than the PVC I originally thought of:

2 x 9.5" x 2" ID x 1/32" aluminum tube + 2 x 9.5" x 1.25" OD x 1/32" aluminum tube = ~0.7 pounds of aluminum. Round it up to 1 pound for rollers alone since I also need rollers to feed it onto the ground glass. With the weight of the extra wood, etc., I'm still easily way way ahead on weight from holders.

on their site their product list includes longer rolls of film (most don't show up as being regularly in stock).

Yeah I found a couple things like this based on earlier comments, but couldn't find very much that seemed reliably for sale. I suppose I should try contacting the company directly and asking. Goes on the list.

I think with this project you might just end up finding out why sheet film is in sheets instead of rolls.

Quite possibly!

I would think trying to roll larger sized film would make it that much harder to keep it flat after it's exposed and developed to be able to get a good quality print from it.

Either scanning or contact prints (which are pretty useful at 8x10) can potentially solve this. The scanner lid or, in the case of a print the glass plate holding the photo paper and negative together, would maintain flatness. So not too terribly concerned about this.

 

[Gavjenks]

On a related note, does anybody happen to know how 35mm or MF cameras manage to advance the film exactly one frame each pull of the lever?

I know it has sprocket holes, but how do those sprocket holes continue to line up correctly as the thickness of the film increases around the spindle? It should be pulling larger lengths of film per revolution as the thickness increases, which would seem like it would jam it at face value.

Are the sprocket holes in film spaced further apart as you advance further in the roll, or something? My film camera has a new roll of film in it right now so I can't look at it =P

Diagram:


I mean, I could certainly just solve this by calculating out how much the pull changes every turn, and pre-punching the roll substrate at those intervals, so that 2 turns always = 1 sheet and I can line it up in the dark just fine. But if there is an easier way, I would prefer not always doing that. Also, it is wasteful of roll length.

 

[table1349]

..................

 

[Josh66]

If you're going to basically glue the sheets together, the glue will obviously have to be flexible once cured ("super glue" won't work).

3M makes a few adhesives that would probably actually work well (imagine industrial strength contact cement) - but it's kind of messy, takes a long time to cure, and I would never want to have to apply it in the dark...



As far as the diameter of the film on the take-up spool increasing as you advance the film, I don't think that necessarily matters at all.
The take-up spool doesn't have to be the thing actually advancing the film. It just needs to be there to hold it. Or, it could have a clutch that would free it up after a certain amount of film has moved across the mask (some sort of roller touching the edge of the film could be used to measure how much film has advanced), stopping it from advancing more film.

Not sure how 35mm or 120 cameras actually take care of that, but if you had access to the drawings of one, or were willing to take one apart - it should be pretty easy to figure out.

 

[Derrel]

I thought you were some kind of mechanical engineer??? There's no need to calculate ever-increasing film takeup spool diameter. There's a much simpler and more-reliable, more-versatile method that allows for many slightly different film thicknesses and reliable,accurate film frame spacing on rolls of any length from 12 to 72 frames, and even worked on long-roll 35mm cameras equipped with HUGE magazines full of bulk 35mm film.

35mm film has a standardized perforation spacing, called Kodak Standard pitch – KS-1870. This world-wide standard allows for the design of cameras that simply advance each frame by eight perforations, or approximately 38 millimeters. The gap between the frames is supposed to be two millimeters.

 

[Josh66]

Are the sprocket holes in film spaced further apart as you advance further in the roll, or something? My film camera has a new roll of film in it right now so I can't look at it =P

8 holes per frame, for the entire length of the film.

 

[Gavjenks]

Is it like the left, or the right side? Or something else?

I see problems with both. On the left, it would always pull exactly one frame, but there would be nothing keeping the receiving spool tightly wound. On the right, the pegs get further apart as the film winds, so evenly spaced holes would tear.

Or is it like on the left, but there is some sort of ratchet/transmission between the two spindles or something? or is the receiving spool spring loaded and works like a clock escapement, or what?