Silver chloride based photo emulsion

[Máx Arnold]

Hi there! This is a question for anyone that has made silver gelatin emulsion. (Mostly for PhotoEngeneer, but I don't think he'll answer... His posts are awesome!!)
Has anyone made a silver gelatin emulsion using only sodium chloride as a halide source? Making an emulsion that is rather slow, but could work.
If so, what ISO did you find the emulsion was? I've read somewhere that silver chloride emulsions can have an ISO as good as ISO 6, which is super ideal.
The thing is that I want to make an emulsion, but spending $40 on potassium bromide doesn't seem fair to me!
Also, I have access to table salt (sodium chloride) that is been iodated. Could this make a small amount of silver iodide?
Again, because of the price, is there another silver precursor for the silver halides? Silver nitrate is very expensive too... My always unanswered question is where did Talbot get his silver nitrate... I guess I'll never know..

Thanks by now

 

[Dahod]

I haven't tried it but Denise Ross has a substitution chart in her book "Handmade Silver Gelatin Emulsions" that lists NaCl as well as KBr. Great book and I'd recommend her web site as well ( https://www.blurb.com/b/6465389-the-light-farm )

Maybe there's some additional information there for you.

Regards
Dave

 

[removed account4]

hi max

i'd suggest going to thelightfarm.com ( denise ross' website )
she has a lot of information there.
here's chris patton's seawater emulsion ( you can make it with seassalt and water )
http://thelightfarm.com/Map/DryPlate/Patton/other/glassplate.htm
think salt print but in gelatin emulsion ...
i made something similar but i added in some bromide cause i had some lying around
and the last time i made it i added in a few cc's if dilute dektol by mistake
( it was supposed to be hypo but i misread the bottle ) and it was super fast instead of super slow

have no clue where the science guys in the 1820s got their silver nitrate im guessing they made it themselves
good luck !
john

 

[138S]

Again, because of the price, is there another silver precursor for the silver halides? Silver nitrate is very expensive too...

Well, let's say that Silver is expensive and nitrate not, so other precursors may not be cheaper because you substitute cheap nitrate and not expensive silver.

 

[Photo Engineer]

Pure Silver Chloride emulsions can be made with an ISO of about 25 - Outdoors and with no UV filter. It has very high UV sensitivity and can come through very well for you. Indoors, with the same emulsion and camera under tungsten light, you will be lucky to attain an ISO value of 0.1 - 0.5. And, chemical and spectral sensitization is not very easy with pure AgCl.

Do not use Iodized table salt. It contains enough Iodide to do bad things, and also the stabilizers or anti-caking agents can hurt things.

PE

 

[Máx Arnold]

Hi there.
Thank you so much for the replies, I'll for sure check the links above.
The Light Farm has great emulsion recipes, so I'll explore it on some more detail.
What jnantz says sounds great! So I'll have to check on that matter as well. I've been reading on the developed salted paper process thread, and one PDF that the creator attached said that citric acid is a very mild developer, and this shortens exposure times. Seems like a good idea...
Yeah, I know the nitrate is cheap and the silver is not.. I just asked because maybe someone of you knew of some market trick. (Economics are crazy, sometimes you find cheap things that should be a lot more expensive...) Maybe making silver nitrate from silver 925? Silver 925 is silver used in jewlery. It has a purity of 92.5, being the rest of the percentage copper and tin, mostly. I fear the impurities will ruin the emulsion, as does idodate in the salt. Maybe then purifying it?
On other news, Photo Engeneer replied! I really thank him! He's great...
What he says is very interesting also, and I'll take his advice. Won't be using iodized salt... No, no.
ISO 25 is more than ideal! Ripening and adding the silver slowly will for sure do a difference, and adding the developer may be a good idea, at a very dillute rate (If not, there may be fogging...) Also, ISO .5 seems great as well, since I'm pretty sure cyanotypes have got a lower iso than that, But since I can't compare with anything, I can't measure it.

Regardless of cost, Thank you.
- Max

 

[Photo Engineer]

Remember that the ISO 25 is an "apparent" value due to UV radiation outdoors and the use of NO UV FILTRATION. This includes lens coatings!

Many people misunderstand this.

PE

 

[Nodda Duma]

The effective speed rating will also be heavily dependent on time of year and time of day as typical UV levels change quite a bit.
I’ve been working to add info on this variability to my Technical and Tips page on my website, digging up old exposure compensation charts ... of course the info is geared toward iodo-bromide emulsions... chloride emulsion will see more significant deltas.

To Ron’s point, when you’ve made your emulsion, use older lenses as newer designs incorporating lanthanide glass and UV curing adhesive will inherently block the spectrum that a silver chloride emulsion operates in.

Cheers,
Jason

 

[dwross]

Is KBr really $40 in Argentina? 100g costs about $6 at Photographers Formulary and Artcraft Chemicals. Perhaps you can find a mail order source? AgCl makes lovely paper, but the ISO is quite a bit less than 1 and the emulsion will be very contrasty. I think you'll be much happier with KBr negatives (my opinion, of course). Good luck and fun!

 

[BrianShaw]

The effective speed rating will also be heavily dependent on time of year and time of day as typical UV levels change quite a bit.

... and latitude.

 

[Máx Arnold]

Is KBr really $40 in Argentina?

Yes, I'd probably be way better with bromide negatives...
Here 250 grams of KBr cost USD 35.14 that's 14 dollars the 100 grams. But that's dollars, you still have to calculate the price into local currency and it becomes a rough ARS 2,102
..
So, yeah... There's probably somewhere cheaper...
And another thing to mention is that I like experimenting quite a lot... So I think of the alternatives... Like what if I use iodide and nothing else...

And yes, the amount of UV light available changes quite a lot around the glove, and yes, I will have to use old lenses. To me, that isn't that much of an issue, since I like the images formed by magnifying glasses..

 

[138S]

So, yeah... There's probably somewhere cheaper...

Reagent grade chem is usually expensive because its purity is usually expensive to obtain. Photo grade chem may often contain impuritires that should not be harmful for that application, so knowing what impurities can be allowed has always been a competitive factor in the industry.

 

[Photo Engineer]

A pure Iodide emulsion is almost impossible to work with!

PE

 

[laingsoft]

From one of PE's old posts, you can technically use d76 as a monobath on pure agcl emulsions.

 

[removed account4]

to update my post ...
I used chris patten's recipe with water from my local bay ( no KBr or anything else added ) and have been getting great results.. can't complain one bit !

 

[Peter Schrager]

to update my post ...
I used chris patten's recipe with water from my local bay ( no KBr or anything else added ) and have been getting great results.. can't complain one bit !

post a picture for us please
great!!!

 

[Peter Schrager]

Johnare you making plates???

 

[removed account4]

hi Peter
I am not washing the emulsion and coating paper with it.

 

[Máx Arnold]

Oh, that's so nice!! Yes, post a scan if you'd like; I'd like to see it

 

[removed account4]

I have a few things in my gallery here I can show you
some are unfixed sun prints, others are sun prints that I soak and
wash in salt water, and the attached image is a print from a glass cyanotype negative
that was printed and fixed in modern photochemistry... the colors happened when I scanned them
there are subtle colors in the print...

https://www.photrio.com/forum/media/leaf.62366/
https://www.photrio.com/forum/media/photogram-unfixed-leaf.62465/

 

[Máx Arnold]

What an awesome (And pictorialistic, abstract) work!
This tells that the emulsion works, at least for this.

 

[removed account4]

Hi Max -
Thanks !
If you go to the light farm and check out the link from above you'll see mr. patten's work. He is doing in camera negatives and prints. His sea water emulsion is very nice, slow, but nice. Think "salt print" slow ...the trick to get long tonality is to slowly mix part A+B years ago. Asked PE about coating paper with salted gelatin to be used at "a later date"... and adding. the silver afterwards ( like you would do with a salt print ). going to be doing that ( and a few other things ) next...
good luck with your fun experiments !
John

 

[bdial]

John,
Salted gelatin sounds interesting, I'd be interested in hearing about your results. As it happens, I just received an order I did from B&S, a salt print kit + some gelatin (just because), and some gold toner.

 

[Máx Arnold]

I am not washing the emulsion and coating paper with it.

You didn't wash it? Am I right?
Regarding this emulsion being UV-light sensitive... How so? Purely UV sensitive? Or uv-and-a-little-blue? I'm not expecting anyone to know, though.. it's just important for the next question: Could it be made using an alcohol burner? A spirit burner doesn't produce that much light at all, might not even produce any UV light. Maybe if I use some kind of mask to prevent the lgiht from spreading, it could work. Not talking about candles, though. Those are engineered to give as much light as possible.
The problem is not speed, though, but practicality. It is about tweaking the emulsion making process so that it could become easier (and less frightening!). Adapting to uncontrolled and more, well, normal circumstances. Getting good enough results but under different, more mundane places. Makeshift darkrooms, flame burners, impure chemicals (some even coming from the grocery store), stick stirring, common glassware... They are not capable of producing perfect emulsions like you'd get from ilford, that is not the intention, but getting something usable and artistic.
What is sure is that there is certain things that should be kept and not replaced: Silver nitrate, a lab thermometer and a gram scale.

I'm really thankful for all the replies and the help given.

 

[removed account4]

hi max

right. I didn't wash the excess salt out of the emulsion. you have to do that if you want to coat it on glass plates, but since paper is able to be washed and saturated you can skip that step. so that means you don't have to noodle it and put it in a cheese cloth and rinse it before your 2nd melt. im not sure if you go to the light farm but it is Christopher patten's recipe I am using (less the washing step)...
im not sure what you mean using a gas alcohol burner, you mean to expose it ?
In my opinion I don't think it will work but I'm no expert by any stretch of the imagination. it needs UV light like most antique processes, its basically a salt print using gelatin ...
there are other emulsions on the light farm website and Denise's book ( available on blurb to preview too ). I've made some of them, they aren't too hard, actually pretty easy. the hardest part is putting the silver nitrate in the solution slowly.
a few years ago I was making a variant of Kevin Klein's emulsion on the light farm and because of user error on my part I didn't use extremely dilute sodium thiosulfate in one of the steps but extremely dilute dektol .. It ended up making the emulsion super fast, how fast? IDK. would it work with a spirit lamp? no idea. but if you have money to spend, and time on your hands it might be fun to see . just to let you know how fast. ..
have fun !
John