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

[Mike_E]

An 8X10 Graphmatic (that didn't scratch) would be pretty cool.

 

[Light Guru]

I now see that you just want to make a weird gizmo rather than answer a practical photographic desire, so I'll answer in that vein.

Exactly.

Another common issue is film/GG registration. Because your System 1 would have quite a large mismatch between the plane of the film and the plane of the GG you would probably want a little quick system to rack focus out that fixed amount after focusing on the GG

Good point. With his design the film plain will be so far back from where the ground glass normally is he has also made it so the camera is going to be limited on what lenses you will be able to use with it. You will not be able to use a 90mm (roughly 30mm equivalent on a full frame DSLR) lens with a camera that has his roll back on it, I doubt a 150mm (roughly 50mm equivalent on a full frame DSLR) You may be able to use a 210mm (roughly 70mm equivalent on a full frame DSLR) but you will not have any room for movements as the lens will be moved so far back because the film plain is being moved back 3-4 inches as the OP estimates the added thickness his roll back would add.

I don't know how much experience you have with LF

Good point. If the OP does not have much experience shooting large format then I suggest he get a fair amount before diving into a project like this. I would even suggest that he head over to the large format photography forum as he will reach many more people who are familiar with large format shooting.

 

[Gavjenks]

I now see that you just want to make a weird gizmo rather than answer a practical photographic desire, so I'll answer in that vein.

Your film curvature test isn't really about damage, but about the resulting curvature set at the time the film is exposed - which may be seconds after it comes off the roll. Film flatness is already an issue with conventionally-used sheet film, and existing large roll film aerial cameras can use vacuum flattening. You could use vacuum flattening via a perforated GG.

Another common issue is film/GG registration. Because your System 1 would have quite a large mismatch between the plane of the film and the plane of the GG you would probably want a little quick system to rack focus out that fixed amount after focusing on the GG - not dissimilar to the idea of racking to 'chemical focus' in the good old days of my youth - ie the 19th century [sic​].

I don't know how much experience you have with LF or how much LF film you use or want to use. Once upon a time I would have suggested trying Quickloads with a GG-modified holder (a holder with a GG and dark slides on both sides). That system would still be quick and light, and would get round the curvature set that roll film would create. You would not be the first to design a reusable Quickload-type system for holding standard sheet film. It would also make switching film or switching development easier.

Remember that LF aerial roll film is thinner than sheet film for a good reason.

If you stick sheets to a long roll backing, how will you avoid feed problems at the leading edge of each sheet (which will be wanting to curl up)? Not insurmountable, of course, if going one way, but more of a problem for your reversible idea. You may also have problems with the difference in relative length when rolled and when flat. That would be solved by fastening the leading edge only.

I guess that when doing a practical evaluation you have to ask if your whole system (camera to print) gives you the quality you want when compared to, say, a Mamiya Press shooting 6x9 film with the very good holder that those Mamiyas use. Will you be printing optically or scanning and printing?

Thanks for the variety of useful input!.

I really like the leading edge attachment-only idea.

Vacuum flattening is intriguing as well. I have some experience with this sort of thing from another project of building a pipe organ. I think positive pressure inside the camera body may be easier, though (also with perforated GG). Pumping a bike pump a few times attached in the side with a tire valve+ air filter in a moderately airtight box prior to tripping the shutter = flat film! And unlike vacuum, it doesn't create an issue of how to avoid things getting in the way of looking through the GG. Then, if you wanted to make it more automated at the expense of more weight, you could easily substitute an electric car tire pump for the bike pump without needing to alter the design at all. Lol.

If you want the film to lie flat, your system should probably arrange so that when the sheet is in position to be exposed, the tensions on it tend to curve it in the opposite direction to the curve it takes on your "rolls". The Mamiya RB/RZ system places the rolls behind the film plane, for example.

How does this not scratch the emulsion as it grinds across?

With his design the film plain will be so far back from where the ground glass normally is

Eh? It would be right on top of the GG. The film would be unspooling from the back of those tubes, not the front, in case that was unclear. And I would rig up some sort of system so that film actually rests inside the tube (maybe 2 nested tubes? Not sure yet), for light protection anyway, so the feed location would always be constant. Metal guide rails and/or something like the air pressure flattening system would then make the film less than 1mm from the GG.

Good point. If the OP does not have much experience shooting large format then I suggest he get a fair amount before diving into a project like this. I would even suggest that he head over to the large format photography forum as he will reach many more people who are familiar with large format shooting.

I borrowed a friend's for a couple months. So a little experience. Neither none nor a lot. I realize this may lead to me making dumb mistakes, but I will learn most efficiently if I am forced to build with a bit of a challenge. The main goal is fun and learning and a unique product, more so than never making a single mistake and getting it all right the very first time. *shrug*

 

[table1349]

http://thefitnesstutor.com/wp-content/uploads/2011/11/Edited-Caveman-cartoon.jpg


Besides, it's already been done.
Film back for a 6X7 http://static.photo.net/attachments/bboard/00Z/00ZSiV-406311584.jpg

4X5 Calmet roll film back: http://static.photo.net/attachments/bboard/00K/00KUSw-35686584.jpg

6X17 with film back: http://farm3.staticflickr.com/2554/4116837447_41bf0d0cf0_z.jpg?zz=1

Of course if you are going to do this project. I say do it right. This is the camera to shoot for with a roll film back: http://petapixel.com/assets/uploads/2013/02/largestview.jpg

 

[unpopular]

Arista Ortho Litho Film 2.0 24 in. x 100 ft. Roll | Freestyle Photographic Supplies

for example.

Develop in dilute rodinol 1:75 or greater depending on contrast. Could probably be processed in an open drum dipped into a tray and continuously agitated by rotation; 10' roll length could be developed in a 4' drum, and 5' lengths fitting inside a standard 55 gallon shipping drum.

A 24x6" camera would provide 10 exposures on a 5' roll.

Be prepared to go through a LOT of fixer.

 

[Josh66]

Now that's a big roll of film...damn.

 

[table1349]

Arista Ortho Litho Film 2.0 24 in. x 100 ft. Roll | Freestyle Photographic Supplies

for example.

Develop in dilute rodinol 1:75 or greater depending on contrast. Could probably be processed in an open drum dipped into a tray and continuously agitated by rotation; 10' roll length could be developed in a 4' drum, and 5' lengths fitting inside a standard 55 gallon shipping drum.

Be prepared to go through a LOT of fixer.

Cool, I just ordered 10 rolls.

 

[unpopular]

^^^ LOL - well? the OP asked!

 

[table1349]

^^^ LOL - well? the OP asked!

I was thinking that with an xacto knife a strait edge and a leather hole punch I could turn it into 35mm film on the cheap.

 

[unpopular]

There are other graphic art films. But a lot of them are really weird, frequently designed for IR laser imagesetters. I have no idea how well they'd develop out in photochemistry, or if they are silver-based at all.

Imagesetting Film | Lowest Prices on Imagesetter Film

If you can find some on ebay for cheap, might be fun to play with. I had a few rolls, but never got around to playing with it and ended up getting stored in poor conditions and just threw it away.

If in doubt though, rodinal!

 

[unpopular]

^^^ LOL - well? the OP asked!

I was thinking that with an xacto knife a strait edge and a leather hole punch I could turn it into 35mm film on the cheap.

LOL! At least it's ortho. If it were Pan you'd have to have a truckload of band-aids near by.

 

[Josh66]

So, a roll of 120/35mm (same area) is roughly 80 square inches ...right?

If you cut that thing into ten 2x10 foot rolls, it would be (per roll) 2880 square inches (36 times the area of a 120 roll). Yeah, you'd be going through the chemicals pretty quickly...

 

[unpopular]

I used to process 11x14" industrex direct x-ray film. Granted, this was a thick, VERY dense emulsion on both sides of the base (weird), that stuff just ATE fixer.

 

[amolitor]

Uh, the RZ/RB system is hard to explain, but the emulsion is not dragged across anything. Here is a crude picture:

 

[Gavjenks]

Uh, the RZ/RB system is hard to explain, but the emulsion is not dragged across anything. Here is a crude picture:

View attachment 49133

Oh okay, no that makes perfect sense. I assume you could make the sides of the plate rounded too to prevent extreme radius bending.

Thanks!