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Thinking about 35mm Home Brew

kb3lms

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Location
Reading, PA
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35mm
Sometime over the next year I have decided to try and make my own emulsion and coat onto film. Right now, I am just beginning to collect parts, pieces and materials to do this. Naturally, wanting to make this as difficult as possible, I'm going to start with 35mm. 120 or sheet film would surely be easier but I don't have a camera for it. (That might change but it's not happening right now)

Clear 35mm film leader is readily available. Assuming I can figure out a way to "sub" the material, does this leader work well as a base? My plan at the moment is to use the subbing recipe from the Wall textbook but am definitely open to other suggestions if anyone can point me at a good formula.

Thanks!
 
Since it's easier to do sheet film why don't you just buy a view camera? It wouldn't be too expensive and making your own size would make your cost significantly higher.
 
I didn't have very good results with the subbing layer mentioned. I had problems with base wringling when the subbing dries.

I had great results in "subbing" POLYESTER with corona discharge. I used a commercial corona unit and also made one by myself as shown here: http://www.youtube.com/watch?v=StgbV766dqQ . However, it broke down for an unknown reason and when I was repairing it, I got a jolt (just 230 V ;D) and left it alone for a while. I'm thinking of designing an easier-to-build, smaller and safer alternative... When it happens, I will give instructions to build one.

The result with corona treated polyester, coated with coating blade, was nearly perfect. I shot it in medium format: http://www.students.tut.fi/~alhonena/emulsio2010/ekanega_1200dpi.jpg and as you can see, the rate of defects is so low it could be done in 35mm.

However, if you are going to coat 35mm leader, you will have a problem with emulsion running to the perforations and off edges. Thus, you should use a bit wider film without perfs, then cut it down and perforate after coating. I have presented an inexpensive way to perforate 35mm with "good enough" quality for still film use: (there was a url link here which no longer exists)
 
kb3lms,

I hesitate to step in with an opinion, because I really do 'get' wanting to pursue a tough path, but...here I go anyway with an opinion.

35mm is as hard a thing to manage in the handcoated biz as you can get. And, in the beginning it's not the right thing to be concentrating on. Learn to make an emulsion first. Make a lot of them, one after another. Fancy will follow from practice. Even if you don't want to be a 120 format photographer, old and not-so-old 120 cameras are available for a song. It's very easy to get the spools and backing paper. It's big enough to be easy to handle and small enough that you get a lot of bang for the buck. The money you save from experimenting with something very likely to work well for you will pay back the cost of the 120 gear in about a day (well, maybe a slight exaggeration, but only slight )

Also, I'm not familiar with the 35mm material you reference, but it's important to determine if it's polyester or acetate. Wall's formula is very good, but it only works with acetate film, and then with a fair bit of flaws by modern film standards. My suggestion for you is to start with commercially subbed film. More info here: http://www.thelightfarm.com/cgi-bin/htmlgen.py?content=28Nov2011

This is a great time to get started with diy emulsions. PE's book and DVD are sure to be great resources. And, of course, I'm also partial to The Light Farm. And, old books. And APUG. But, at the end of the day, what's really important is just digging in and getting started. OK, enough preaching and cheerleading from me. Best of luck and fun!

d
 
Another problem that may crop up is the fact that most emulsions available ready made or do it yourself from formulas, are rather coarse grained and best suited to MF or LF and not 35mm. Grain and sharpness may then be a severe issue for you.

PE
 
Actually, diy emulsion grain can be almost invisible. Unfortunately, the conflicting issue is then slow speed. I don't think it'll ever be easy to make artisan film that has both the speed and fine grain of the most modern commercial films, but I also don't think that will be seen as problem by folks wanting to roll their own.

hrst: you can almost eliminate the wrinkles in subbed acetate by sandwiching the film between two sheets of 1-ply mat board (or similar) and applying a warm clothes iron, followed immediately by cooling under a weighted surface. It takes just a bit of experimentation to get the right temperature, but it does work. Having said that, I look forward to the next round of your corona discharge experiments!
 
Denise, you are correct. You might get good grain and sharpness in 35mm but at a severe price in speed. If you want decent speed, then you pay the grain price.

Also, I am working on home brew high speed emulsions, but so far the results have not matched expectations. The best is about ISO 100 with a 1 micron grain. I know that I can do better, but it will take time.

PE
 
Our ISO25 was very fine-grained, comparable to traditional ISO100ish films like Plus-X or APX100. So, you lose "only" two stops by making your own, old-style emulsion compared to modern commercial products. 2 stops only, it's not so bad, completely usable!
 
This product has been available all the time, but I have never bought it because I have thought IT'S TOO EASY, it feels like cheating. But maybe it can be bought with an excuse that you first practice making just emulsions and want to coat easily for time being. Then, later, you can start making your own acetate from your own cotton field. Maybe I should place an order.....
 

Not so bad at all! I really, really hope you start cooking again.

re The Formulary's subbed film: 7 mil is perfect for sheet film. It's too thick for roll film.
 
The Photoformulary support is 7 mil which does limit the length of a film roll that can be wound on a spool. It is ideal for LF though.

PE
 
Well, I'm willing to do 120...

... but my real reason for looking at 35mm is because that is the equipment I have. However, I can see why 120 film would be easier and it's not going to be hard to talk me into that. Adding to the collection is NOT a problem for me. But to go down the MF path, I have to slip a camera AND silver nitrate and all the other stuff in under the radar. It can be done, of course, as long as the financial manager doesn't figure out exactly how many $$$ are going out the door on this project.

What's a modestly priced camera to start with? Almost all of my 35mm equipment is Pentax so I've been looking at Pentax 645's on the big auction site and KEH. Is that a good way to go? I'd want something with some room for growth (lenses etc.) I can tell you that, unfortunately, that Hassleblad's need not apply.

-- Jason
 
BTW, "The Light Farm" is a great website and "The Book" is on my list!

Also with regards to a mixing machine, would a blender work? There is at least one in our kitchen closet that hasn't seen the light of day in about 15 years so it will never be missed.
 
A blender can be to vigorous for emulsion making due to the fact that the blades at high speed can crack grains and also too much air can be whipped into the emulsion. A propeller mixer on a controllable drill does just fine.

PE
 
Photo Engineer said:
A blender can be to vigorous for emulsion making due to the fact that the blades at high speed can crack grains and also too much air can be whipped into the emulsion. A propeller mixer on a controllable drill does just fine.
Click to expand...

Like one of those paint mixers you can buy at the hardware store? And use it at a fairly low speed? I have a nice drill stand for the drill so that would work out OK.

Don't those paint mixers resemble the mixer that you had talked about a few months ago?
 
I have a set of Stainless Steel prop paint mixers, but the plastic kind would probably work. At our scale, about 300 rpm is just about right for a 100 - 500 ml batch.

PE
 

Jason,

Actually, I'm thinking really, really basic (and cheap.) Just something to test film with. There are a lot of old 120 cameras and new Holgas, etc. You need to make a lot of emulsions, and figure out how you're going to coat and then practice coating the film strips and loading them on spools. And then, go out and take pictures. Lots of pictures. Try a couple of different developers. Play. Tweak. Curse. Laugh. Keep going.

For the camera and darkroom odds and ends, check ebay, or even better, the APUG classifieds. The only thing to make sure is that the camera has a B(ulb) setting. Making emulsions is nowhere near as complicated as it can seem on some of these threads, but there is a certain amount of time required to assemble the equipment and workspace, and unless you're a savant, you probably will have a little time before you have to decide on your ultimate dream camera system.

Hopefully, this all sounds like a wonderful challenge and you can hardly wait to get started! I won't kid you. There's a learning curve, but WOW, the payoff.

The best of luck and fun,
d
 
Hi Denise,

I started looking for some alternative cameras on ebay and identified a nice Ansco folding 120 camera to go after. They aren't expensive and readily available. It'll be awhile yet before I make anything, but it'll be a cool, vintage camera to use while I am collecting backing paper, spools, etc.!
 
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