Making 1925 Gelatin Emulsion and Coating Film for 1925-2025 Leica Centnnial

Not sure if this forum is interested but I am currently creating new 35 mm film with a 1925 era ISO 12 blue sensitive film for shooting in a 1928 Leica I camera. This also has an anti-halation coating on the back. It is based on a roll of film shot by Oscar Barnack in 1914 that I currently have on loan for analysis and comparison.

@Mark Osterman I think I'm speaking not just for myself in saying that there's interest in whatever you do in terms of photography! This development in particular is interesting in many ways; is this something you intend to do an in-depth write-up on? Or are you planning on other forms of dissemination of the knowledge/experience gained?

The color of the emulsion is quite particular; is this due to the use of a particular sensitizing dye? Or an antihalation dye? The example photo appears to have surprisingly good halation performance given that it's (probably) a relatively simple emulsion. Can you share the recipe and parameters used here?

The coating machine also piques my interest and I'm sure others will be interested to hear something about this as well. Is this a piece of equipment that you have access to through the relationship with Kodak? It looks like a very functional/professional experimental lab coater to me.

Sorry for the questions; I hope you don't mind. I'm just thrilled to see you drop in here!

Hi Mark,

very interesting project.
Did you use a dye like erythrosine to extend the sensivity to green like in ortho films as Silbereosin of those days, or is it a plain blue/violet sensitive emulsion?

Best
Jens

Hello All,

I’m never quite sure if I was ever on this or other forums when I come on them. I thought this particular project of mine was significant enough that there may be others who are interested. It all started when I had the opportunity to buy a 1928 Leica I camera last November. I had already been working on a project of making the emulsion and coat paper based film for the very first Kodak camera.

I left Eastman Museum in 2020 after twenty one years during the pandemic. They saw I could no longer bring in paying workshop participants so they closed down my department and now my wife and I offer instruction in many different processes from our Rochester studio and elsewhere. When I was at Eastman Museum I brought in an experimental film coating machine that was made at the Polaroid Research Lab and then went to RIT and then fell into my hands. We taught how to make 35 mm cine film there and shot that in a hand crank Eyemo camera. When I left the Museum followed by my assistant Nick Brandreth, he brought the machine home and gave it back to me. He neglected to secure the perforator so I couldn’t make the 35 mm film.

A few moths ago Eastman Kodak Company gave me a Bell & Howell perforating machine and 1000’ of 5” wide acetate film stock as a gift to allow me to continue research. So … with both machines I could go back to the most modern process I do .. gelatin emulsions. As it turns out this year is the Centennial of Leica introducing their production camera, the model I which I bought in November.

Since January I have been working on making the very same type emulsion and film as first used by Oscar Barnack in 1913-14 in his experiments and also available in 1925. In the past two weeks everything came together for me. I have a clean working ISO 12-14 blue / violet emulsion and I have the coating machine calibrated to work nicely. Have made three batches that I have tested first on glass plates and then film. I discovered however that there was a considerable amount of halation.

Last week I was given an original roll of 35 mm film negatives shot by Oscar Barnack in 1914. It has been invaluable for comparison. His film had no halation. So a few days ago I started experimented with making an anti-halation backing and settled with an alcohol based red dye. It worked perfectly and is the reason for the pink salmon color. The emulsion is actually a light yellow. It worked but then I had to remove it and a wash of dilute grain alcohol does that perfectly. Unfortunately my early Leica came back from repairs shredding my film. I subsequently tested my film in other Leicas and discovered it was the camera not my film and sent it back for more adjustments. Anxious to use my film in that camera.

France and I had to come to Sicily a couple of days ago to teach our yearly workshop in dry collodion negatives so my experiments had to stop. We return the first week of June and I’ll be right back to it, but I did bring two rolls of what we are calling MO-1925 and a Leica IIIa to do some test shots here in Sicily and a short stay in Rome before we return.

I should add that I also collected the original 1925 glass developing drum for development by inspection and the earliest adjustable enlarger for printing. We are working on doing a video showing all of the above and of course I’ll wrote some illustrated pieces for publication. Leica Company is encouraging me to do all that. I am not much of a drum beater myself.

So, you are now caught up … I think.

Images showing the first exposure test of my film on a small snippet of unperforated film taken in a Pentax SLR camera. Note the halation up in the sky. This was taken care of by adding alcohol solvent red dye to the back of the film in later tests.

I was asked specifically about the anti-halation layer. Here is a section of an original Kodak black and white graphic arts film on glass with a water soluble anti-halation layer. I was curious how long it took to dissolve. My problem was with the drying time after coating the plates with solely water soluble colors. I decided on alcohol soluble dyes because I could add stronger grain alcohol and even ether to make the applied layer dry much faster. The coatings were easy to apply and very good and they didn’t really need to be so intense. I opted for a warmer hue. However removing the dye took too long in just water so I added some alcohol to the final wash which worked nicely.

Fascinating stuff, Mark.

Did you run into that classic problem of static when shooting this stock in the hand cranked Eyemo?

As you are well aware, it was a real problem for cinematographers well into the late 1910's; how did you cope with that?

This has been a improbable dream of mine for over 40 years; to make cine stock from scratch! I have an Acme 16/35 optical printer, but could never find a perforator within reach.

Anyway, please do keep us updated! I will live vicariously through your actions!

Very very intersting project.
I have a 1930 Leica I and sometimes wonder how the original owner experienced the process of photographing with film that had very limited sensitivity to both color spectrum and light.
No light meter, probably having to source bulk film and roll their own FILCA cassettes and other inconveniences I don't even know about.
The whole idea of this camera being state-of-the-art in miniaturisation & quality 100 years ago is fun to think about.
Wonderful that they still are very useable cameras.

@Mark Osterman thanks so much for the quick and fascinating follow-up. I'm glad to hear that while you have lost access to Eastman Kodak House's infrastructure, you've been able to retain/regain some essential equipment and moreover, that you're still very active in the field of exploring and reinventing all these beautiful photographic processes.

Thanks also for the clear answer on the anti-halation issue; it seems very effective indeed!
Do you intend to share at some point the emulsion recipe in its entirety? I imagine it's along the lines of some of the recipes already posted here on Photrio, but I'm sure many would be interested in comparing them. Personally I'd be interested to hear how in this particular emulsion the spectral sensitization is done; I imagine it's something fairly straightforward that would also be applicable for home users, right?

Also:

Mark Osterman said:

I thought this particular project of mine was significant enough that there may be others who are interested.

Click to expand...

I say this without exaggeration: you can safely assume this is probably true for all your photographic projects. Please post often!

Fascinating experiment and tests. Were these early films thicker than contemporary (late-20th century +) film? Have the position of the film rails changed in recent Leicas compared to the ones pre WWII?

Kino said:

Fascinating stuff, Mark.

Did you run into that classic problem of static when shooting this stock in the hand cranked Eyemo?

As you are well aware, it was a real problem for cinematographers well into the late 1910's; how did you cope with that?

This has been a improbable dream of mine for over 40 years; to make cine stock from scratch! I have an Acme 16/35 optical printer, but could never find a perforator within reach.

Anyway, please do keep us updated! I will live vicariously through your actions!

Click to expand...

No, we never had a static problem. We only shot short lengths of film at 8 fps. Here is a sample of film and a student during one of our cine film workshops at Eastman Museum looking at film we coated that morning.

koraks said:

@Mark Osterman thanks so much for the quick and fascinating follow-up. I'm glad to hear that while you have lost access to Eastman Kodak House's infrastructure, you've been able to retain/regain some essential equipment and moreover, that you're still very active in the field of exploring and reinventing all these beautiful photographic processes.

Thanks also for the clear answer on the anti-halation issue; it seems very effective indeed!
Do you intend to share at some point the emulsion recipe in its entirety? I imagine it's along the lines of some of the recipes already posted here on Photrio, but I'm sure many would be interested in comparing them. Personally I'd be interested to hear how in this particular emulsion the spectral sensitization is done; I imagine it's something fairly straightforward that would also be applicable for home users, right?

Also:

I say this without exaggeration: you can safely assume this is probably true for all your photographic projects. Please post often!

Click to expand...

This is only blue violet sensitive as are all emulsions when first made. You can find my basic ISO 1-2 MO-1880 formula and my procedure in the new edition of the Darkroom Cookbook. After you make that (which was used in our plate and cine workshops for years) you would need an additional ripening for 30 mins at 50c and include a sulfur sensitizer (very dilute hypo) to bring the emulsion up to 12-15.

The glass negative here is made with my basic ISO 1 MO-1880 emulsion

Kodachromeguy said:

Fascinating experiment and tests. Were these early films thicker than contemporary (late-20th century +) film? Have the position of the film rails changed in recent Leicas compared to the ones pre WWII?

Click to expand...

I would say that the film stock was thinner than Polyester. Don’t know about Leica comparisons.

Nitroplait said:

Very very intersting project.
I have a 1930 Leica I and sometimes wonder how the original owner experienced the process of photographing with film that had very limited sensitivity to both color spectrum and light.
No light meter, probably having to source bulk film and roll their own FILCA cassettes and other inconveniences I don't even know about.
The whole idea of this camera being state-of-the-art in miniaturisation & quality 100 years ago is fun to think about.
Wonderful that they still are very useable cameras.

Click to expand...

Well, it’s the purpose of this research to gain an understanding of shooting with a Leica in the first few years. I am using the early camera, making the earliest film, developing in the 1926 rotating drum and enlarging with the earliest enlarger. By the way, in regards to the original cassettes. When I had my camera serviced recently they switched two screws that attach the top plate and a longer one went into the film loading chamber preventing the FILCA type not to go all the way in … preventing the baseplate from being installed.

The 1925-26 Leitz film developing drum. These were only used with film that could be processed by inspection under red safe light. So ordinary and orthochromatic films.

Hello Mark,

When you return, can you please take some clear photos of the coating machine, perforator and slitter (if there is one) and post them? Maybe with something alongside to provide scale? I suspect that the photos can provide useful information to allow duplicating the devices, or incorporating aspects of their design. If there is printed user material that went along with this equipment, do you have that as well?

Also...did you perforate the film after coating the emulsion, or before?

Thanks,

Bob M.

This is one of the coolest things I've seen in my years here.

I recently saw one of those Leitz drums in an auction and was wondering who would be crazy enough to buy it. Now I know!

Mark, do you have a blog or website following your progress on these things?

Patrick Robert James said:

This is one of the coolest things I've seen in my years here.

I recently saw one of those Leitz drums in an auction and was wondering who would be crazy enough to buy it. Now I know!

Mark, do you have a blog or website following your progress on these things?

Click to expand...

LOL .. yes, but I am not really a collector. I buy these things for use in proof of concept. It works wonderfully for development by inspection, something no one has seen in many decades. My work is regularly posted on my facebook page. The books where I write my findings are generally for the photo conservation community, but my wife and I regularly teach workshops and private tutorials in our studio.

rmazzullo said:

Hello Mark,

When you return, can you please take some clear photos of the coating machine, perforator and slitter (if there is one) and post them? Maybe with something alongside to provide scale? I suspect that the photos can provide useful information to allow duplicating the devices, or incorporating aspects of their design. If there is printed user material that went along with this equipment, do you have that as well?

Also...did you perforate the film after coating the emulsion, or before?

Thanks,

Bob M.

Click to expand...

Do you mean pictures of the machines in the daylight. I see there is only so much resolution I can share on this site. It has refused some pictures I tried to post yesterday. The coating machine is unique, no manual. It was made in the Polaroid emulsion research lab for their use. Was then sold to RIT and they gave it to me when they discontinued their emulsion technology curriculum. I should add … they actually told me when they put it out on the curb on trash day and I drove over and picked it up!

All film is coated with the widest film stock. It is then slitted to finished size … and then perforated. I coat 5” wide, slit to 35 mm (the slitter came with the coating machine) and then perforate with a Bell & Howell perforator that was given to me from Eastman Kodak.

Here is a picture of me back when I worked at Eastman Museum when I brought the coating machine in to use for teaching cine film workshops. Only the film history students and historians were interested at the time. The general photographic community didn’t care that we could make film. The basic frame for the machine was a Sears belt sanding machine. The coater is a custom made stainless steel slit type extruder. In this picture is configured for the shortest possible coating. The rails and pulley drum are expandable for longer yield.

Mark Osterman said:

No, we never had a static problem. We only shot short lengths of film at 8 fps. Here is a sample of film and a student during one of our cine film workshops at Eastman Museum looking at film we coated that morning.

Click to expand...

I wonder if the reason we didn’t have static was that we were always shooting film we made no older than a day before shooting.

Mark Osterman said:

It has refused some pictures I tried to post yesterday.

Click to expand...

I'm sorry to hear that; it's indeed an issue we bump into sometimes as a result of the file size limit. Here are some hints that may help: https://www.photrio.com/forum/threads/how-to-post-pictures-and-avoid-size-limit-problems.211668
Also feel free to drop me a private message and we can set up some way where you send (e.g. via email) any photos you'd like to post and I'll put them in. But I'll just do the same things outlined in the link above.

Mark Osterman said:

I wonder if the reason we didn’t have static was that we were always shooting film we made no older than a day before shooting.

Click to expand...

I'd expect weather and in particular RH would have played a role, as well as materials used in the cameras. In an all-metal camera I'd expect there to be much less (no) problems with static, but as soon as there's a good content of polymers esp. in the film path, you'd see these issues pop up.

For reference, here is a strip of our basic emulsion film shot in an Eyemo cine camera back when I was teaching at Eastman Museum. It was only ISO 1-2 and yet we got respectable motion picture negatives. That is me driving my 1919 model T. The actual emulsions would have been around that fast in the 1910 era.

koraks said:

I'm sorry to hear that; it's indeed an issue we bump into sometimes as a result of the file size limit. Here are some hints that may help: https://www.photrio.com/forum/threads/how-to-post-pictures-and-avoid-size-limit-problems.211668
Also feel free to drop me a private message and we can set up some way where you send (e.g. via email) any photos you'd like to post and I'll put them in. But I'll just do the same things outlined in the link above.


I'd expect weather and in particular RH would have played a role, as well as materials used in the cameras. In an all-metal camera I'd expect there to be much less (no) problems with static, but as soon as there's a good content of polymers esp. in the film path, you'd see these issues pop up.

Click to expand...

I do have a video of the B&H perforator being cranked in the daylight while still in my garage when I was retrofitting it for hand cranking. Can videos be posted here? Also … I post everything I do on my facebook page and people should feel free to go there and do a subject search or just look around … lot’s of interesting photo related things among the model T Ford posts.

Mark Osterman said:

Can videos be posted here?

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Not directly; they'd have to be uploaded to e.g. YouTube or Vimeo first. Then they could be embedded in a post here.

Mark Osterman said:

I post everything I do on my facebook page and people should feel free to go there and do a subject search or just look around

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That's nice; I have no Facebook and I've noticed quite a few more people here on Photrio have stayed away from it.

My facebook page is the primary way we advertise our workshops so it’s a shame people on this group avoid it. That platform allows lots of pictures and videos as well. I don’t place things on Youtube much, but did when I was at the Museum.

I tend to avoid groups like this because there are times when the responses to my posts were from people with lots of armchair reading but no actual hands on experience giving me bad advice I didn’t really seek. I remember Ron Mowrey being very frustrated when posting on Apug and I suggested to him to stay away for his health. Nevertheless I thought this particular recent research should be archived on the internet in a place where people seeking the information might find it after I’m six feet under. So, here I am.

The last project I did in February was to make the same paper based “American” film used in the first Kodak camera in 1887. It’s a slow color blind emulsion coated on a sub layer of plain soft gelatin and transferred to glass after development / fixing. I shot it in a No 2 Kodak. Here is one of the negatives shot in February of the house across the street. It’s not the best light for the process in Rochester winter .. but a decent negative. This is shown on the original support prior to transfer. Need to come back to this in the summer when we have good sunlight so I can shoot this handheld.

Mark Osterman said:

My facebook page is the primary way we advertise our workshops so it’s a shame people on this group avoid it.

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It would go offtopic rather strongly, but I think I'm not alone in having some issues with what Facebook represents and how the business model works. I'm afraid there will always be a group of people who simply refuse to take part in it. Perhaps it's a shame that this results in practitioners becoming divided/distributed across different platforms. Of course, all are welcome here on Photrio. Either way, I think the reality is, and will continue to be, that there are different platforms and no single platform will be home for all individuals within a certain community. We'll have to learn to live with that, one way or another.

Mark Osterman said:

I tend to avoid groups like this because there are times when the responses to my posts were from people with lots of armchair reading but no actual hands on experience giving me bad advice I didn’t really seek.

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There's always a dilemma there; on the one hand we want people to feel free in speaking up, but the drawback of this is that not everything shared is on-topic, relevant or of high quality. I think by and large Photrio does fairly well compared to other online platforms, which is also evident in how many people find this place through online searches for specific information. Lots of pearls, but also lots of mud. It's difficult to get just one without the other.
As to Ron, he was a regular and frequent participant here on Photrio right up to his final days. We all thank him dearly for his commitment to sharing his knowledge so freely through several channels, and he's still sorely missed today. What he has shared here remains easily accessible and indeed intensively used/referenced by many.