Darkroom chemistry in dissolvable tablets

Jesse K · Oct 11, 2021

I'm a 17-year-old who loves all types of analog photography and camera building. I will soon be giving a demonstration (and possible workshop) on pinhole photography and the paper development process. I was browsing the other day when I came across the Tetenal chemistry tablets (https://tetenal.com/en/). I'm curious about the possibility of creating these types of tablets at home using my own developer, stop, and fixer formulas. Would anyone be able to enlighten me on how one would go about this, or if it is even possible? I understand that it would be time consuming to create them, but it would make it far easier to give workshops to younger students and not require me to bring multiple measuring tools. Thanks!

mgb74 · Oct 11, 2021

The tablets are an interesting idea; reminiscent of the old Kodak Tri-chem packs (way, way before you were born). But frankly, unless your usage is very sporadic, you might find it more cost effective to use liquid chemistry.

Jesse K · Oct 11, 2021

Thanks for the reply! I’ll look into those. For personal use, I just use Ilford’s liquid chemistry. However, in one of my classes, I’m designing some pinhole camera kits and I think something like the Kodak packs would be easy to package/ship and result in a more pleasant user-experience. I’ll do some research and see what I can find out in regards to how they were produced.

mgb74 · Oct 11, 2021

Jesse K said:
Thanks for the reply! I’ll look into those. For personal use, I just use Ilford’s liquid chemistry. However, in one of my classes, I’m designing some pinhole camera kits and I think something like the Kodak packs would be easy to package/ship and result in a more pleasant user-experience. I’ll do some research and see what I can find out in regards to how they were produced.

I agree. I didn't realize you were planning to send the chemicals out as part of "homework".

gone · Oct 11, 2021

Just get yourself a fancy-smancy pill making machine.

https://www.made-in-china.com/price/pill-press-price.html

mshchem · Oct 11, 2021

Jesse K said:
I'm a 17-year-old who loves all types of analog photography and camera building. I will soon be giving a demonstration (and possible workshop) on pinhole photography and the paper development process. I was browsing the other day when I came across the Tetenal chemistry tablets (https://tetenal.com/en/). I'm curious about the possibility of creating these types of tablets at home using my own developer, stop, and fixer formulas. Would anyone be able to enlighten me on how one would go about this, or if it is even possible? I understand that it would be time consuming to create them, but it would make it far easier to give workshops to younger students and not require me to bring multiple measuring tools. Thanks!

Tetenal has old existing equipment. Back before digital Tetenal supplied chemistry in tablet form, especially for radiology, X-rays etc. Making and preserving tablets would probably not be the best use of your time.
Better to learn how to dissolve powders, maybe find a neat old (analog) balance or a cheap digital scale and make your own developer from scratch. 5 or 6 chemicals would allow you to make all manner of developers from published formulas.

gordrob · Oct 11, 2021

The Kodak Tri-Chem Pack was an easy way to mix your chemistry back in the 60's. Currently Ilford Simplicity Starter Pack has everything to develop 2 - 35mm rolls of film in liquid concentrates.

removed account4 · Oct 11, 2021

Jesse K said:
Thanks for the reply! I’ll look into those. For personal use, I just use Ilford’s liquid chemistry. However, in one of my classes, I’m designing some pinhole camera kits and I think something like the Kodak packs would be easy to package/ship and result in a more pleasant user-experience. I’ll do some research and see what I can find out in regards to how they were produced.

when my daughter got the famed book "this book is a camera" it came with instructions to use instant coffee as a developer. (table spoon method: powdered Vit c from health food store, washing soda and powdered instant coffee )
stop can be just water and fix .. you can have them use really salty water. your development will be as slow as using the pinhole camera itself
have fun Jesse K.
John

BAC1967 · Oct 11, 2021

I read somewhere not to use vitamin C tablets to make Caffenol. The reason was the binder used to make the tablets hold together. I think the concern was that it would affect the development or get on the negative.

removed account4 · Oct 12, 2021

BAC1967 said:
I read somewhere not to use vitamin C tablets to make Caffenol. The reason was the binder used to make the tablets hold together. I think the concern was that it would affect the development or get on the negative.

I've heard that too, vt c tablets have rose hips in them too sometimes and other weirdness.
maybe the binder in the developer tablets is good clean fun

koraks · Oct 12, 2021

BAC1967 said:
I read somewhere not to use vitamin C tablets to make Caffenol. The reason was the binder used to make the tablets hold together.

Dissolve the vitamin C, filter the solution. Solved!
Or, better yet: don't worry about it. It's unlikely the binder will wreak havoc on the film in any way. A little crud does surprisingly little damage. Moreover it's caffenol - it high quality results are required, surely people will use a more sensible developer.

momus said:
Just get yourself a fancy-smancy pill making machine.

Yes...that *might* work - but probably won't, at least not like that. It will take some R&D to get the stuff to stick together reliably (i.e. binders are needed) and also to prevent the developing agent from oxidizing (likely some kind of coating/encapsulation is required). This makes it more complex than it may seem.

Frankly, an approach with sachets of pre-measured developer sounds like a more feasible idea. Not particularly difficult to realize for B&W chemistry and ziplock bags are cheap and easy to use. If compounds are used that are present in critically small amounts (e.g. phenidone) a vial of a 1% solution or so may be added to the package that the user can mix in with the rest.

The pill/tablet option sounds very nice on paper, but for a DIY solution I fear it's going to create more problems/challenges than it solves.

AgX · Oct 12, 2021

Jesse K said:
For personal use, I just use Ilford’s liquid chemistry. However, in one of my classes, I’m designing some pinhole camera kits and I think something like the Kodak packs would be easy to package/ship and result in a more pleasant user-experience.

Hand out to your students either:

-) the Tetenal tablets
-) the Ilford sachets
-) tiny pharmacy bottles you have filled with the apt volume of concentrate

AgX · Oct 12, 2021

We recently had a discussion whether it is advisable to part the powder/crystal content of packs.

Concidering this positive you may add:

-) selfmade sachets with solid content

With homemade packs though you might get into issues of liability towards your students.

Jesse K · Oct 12, 2021

jnantz said:
when my daughter got the famed book "this book is a camera" it came with instructions to use instant coffee as a developer. (table spoon method: powdered Vit c from health food store, washing soda and powdered instant coffee )
stop can be just water and fix .. you can have them use really salty water. your development will be as slow as using the pinhole camera itself
have fun Jesse K.
John

I've considered using caffenol developer. The only downside is that it's sometimes difficult to see the development occur due to the darkness of the coffee. It takes a bit of the magic away, but definitely still a viable option!

Jesse K · Oct 12, 2021

I doubt the chemicals would mix properly if I mixed them without water. It seems like they're all mixed together in water just below boiling point.

Jesse K · Oct 12, 2021

koraks said:
Dissolve the vitamin C, filter the solution. Solved!
Or, better yet: don't worry about it. It's unlikely the binder will wreak havoc on the film in any way. A little crud does surprisingly little damage. Moreover it's caffenol - it high quality results are required, surely people will use a more sensible developer.

Yes...that *might* work - but probably won't, at least not like that. It will take some R&D to get the stuff to stick together reliably (i.e. binders are needed) and also to prevent the developing agent from oxidizing (likely some kind of coating/encapsulation is required). This makes it more complex than it may seem.

Frankly, an approach with sachets of pre-measured developer sounds like a more feasible idea. Not particularly difficult to realize for B&W chemistry and ziplock bags are cheap and easy to use. If compounds are used that are present in critically small amounts (e.g. phenidone) a vial of a 1% solution or so may be added to the package that the user can mix in with the rest.

The pill/tablet option sounds very nice on paper, but for a DIY solution I fear it's going to create more problems/challenges than it solves.

That's a good point. I didn't think about preserving the tablets. Caffenol may be a good option since you can practically drink it (although it probably wouldn't taste great). I've also been looking at creating a dektol-type developer with ascorbic acid in place of hydroquinone. I'm currently looking at Chris Patton's E-72 Print Developer formula (http://home.alphalink.com.au/~simgrant/jackspcs/pde72.htm). However, the formula is for a liquid stock solution which would then be diluted further. I know this is probably a dumb question, but I'm rather inexperienced in chemical processes - how might I go about creating a dry powder to fill pre-measured sachets? Would I have to dehydrate the stock solution?

Peter Chem · Oct 12, 2021

Realistically your best bet is probably weighing out individual ingredients and shipping them out as a set of numbered/labeled re-sealable baggies along with instructions explaining the order they need to be added in. You could also opt for heat-sealing which would significantly reduce your costs but has a steeper initial investment. I know of an excellent photo store in Poland (Czarno-Biale in Warsaw) that does exactly this for their own line of darkroom chemistry and it's a great (albeit labor intensive) way to provide shelf-stable low-volume niche developers.

Tableting gets extremely complex if you want any degree of control (just see: https://en.wikipedia.org/wiki/Tableting) and I suspect one of the biggest issues for anyone attempting to do DIY photochem tableting would be dissolution time since a tablet that can survive shipping would probably have to be pressed very hard.

fgorga · Oct 12, 2021

Creating tablets is not a trivial undertaking.

The first problem to work out is getting a uniform mixture of the solid components. This is much more difficult than you would think, especially if the particle size and density of the various components are not similar.

Another problem to work out is how to press your mixture into a tablet. Again this is a non-trivial problem. Many solid mixtures will not make reliable tablets without adding some (hopefully inert) binder. Another fact to this problem is the dissolution of the tablet... how quickly and at what temperature the tablet dissolves.

Lastly (maybe), there is the issue of stability... both of the tablet and of the individual components.

Want to know how hard these problems are, ask a pharmaceutical chemist. Drug companies have whole departments just to deal with these issues.

Darkroom chemistry in dissolvable tablets

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