Which Halogen?

I'm pretty new at this and could do with some guidance on choosing a halogen (or halogens).

I want to try making dry plates using albumen as the binder. Aiming for a latent image to be developed. My reading so far into possible recipes seems to indicate that various halogens were used, often in combination. Most common back in the day seems to have been Potassium Iodide, sometimes with another (a Chloride, or maybe Potassium Bromide). What's not so obvious is what sort of effect the various options might have, or why more than one is used.

I'm interested in landscapes and other static subjects outdoors. Exposure times up to half an hour in normal daylight are okay, maybe up to an hour at the most. The plan is to contact print, initially on modern RC multigrade paper. I have an enlarger with a colour head so contrast adjustment when printing is feasible. I'll probably try albumen POP later, more likely with a UV lightbox than sunlight (which is unreliable here in Scotland).

The halogens I currently have are...
Sodium Chloride
Ammonium Chloride
Potassium Bromide

Am I right in thinking that Potassium Bromide is the better option? What would happen if I were to add one or both of the Chlorides? Should I just get some Potassium Iodide?

Nomad said:

I'm pretty new at this and could do with some guidance on choosing a halogen (or halogens).

I want to try making dry plates using albumen as the binder.?

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Just curious. Are you going to use Albumen in place of gelatin in making of the dry plate emulsion (i.e. pre-mixing the halide(s) with silver nitrate)? In your earlier thread about squeegees and rods, you were asking about "sensitizing" which normally means to apply the salt layer first and then add silver nitrate solution to form the light-sensitive silver halide in situ. I am not sure which process you are alluding to. The traditional dry-plate is the former of the two, if I am not mistaken.

I may be making up the process as I go.

I've done a little bit of albumen paper as an experiment (ages ago). With that, I mixed the halogens (the two Chlorides above) with the albumen, and then brushed on the Silver Nitrate when it was dry. It seemed to work.

For the plates, the plan I had was to make a similar albumen and halogen mix, and coat that onto the glass and let it dry. Then add the Silver Nitrate, potentially using the silicone squeegee.

Which halogen salt you use chloride, bromide or iodide effects the speed of the emulsion. Considering printing papers for a moment chloride papers are very slow suitable for contact printing only. Chlorobromide papers are faster and can be used for enlargement.

If you are new to the process I would suggest starting with a known formula. There are quite a few sites that list formulas. Later when you are more familiar with things you might try experimenting but not at first.

Nomad said:

I may be making up the process as I go.

I've done a little bit of albumen paper as an experiment (ages ago). With that, I mixed the halogens (the two Chlorides above) with the albumen, and then brushed on the Silver Nitrate when it was dry. It seemed to work.

For the plates, the plan I had was to make a similar albumen and halogen mix, and coat that onto the glass and let it dry. Then add the Silver Nitrate, potentially using the silicone squeegee.

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I had figured as much. I think it is a great idea. I had been doing some thinking along similar line (to be tackled at some point in a distant future) using an alternative binder. What I would be worried about in using a salted albumen base coat is the that subsequent treatment with the aqueous silver nitrate might interfere physically with it (in addition to the chemical reaction forming the AgX) due to the possibility that it can redissolve the dried albumen. This is a conjecture on my part but you might have to "harden" the binder layer before sensitization, particularly if you are going to use a squeegee.

Good luck. I will be very interested in how it goes.

25 -30 years ago I made a gelatin emulsion using KBr, I let it bake overnight, in a lab oven. I can't remember the exact temperature but I'm pretty sure it was around 100F. I coated paper and it acted like a "normal" Bromide paper. I have a book, it's available on Google E-book, reprint on Amazon very inexpensive. I would highly recommend you looking at this. Photographic Printing Methods, A Practical Guide to the Professional and Amateur Worker, Rev. W. H. Burbank. Scoville 1887. This covers making Dry Plates, coating paper etc. I found an old copy in Univ. of Iowa library years ago, copied it. It is readily available as a reprint and as an e-book.
You still have a blue sensitive material, nothing fancy.
POP is what I would be most interested in.

Still I will stick to Kodak and Ilford . Mike

nmp said:

...subsequent treatment with the aqueous silver nitrate might interfere physically with it (in addition to the chemical reaction forming the AgX) due to the possibility that it can redissolve the dried albumen.

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Not an issue. The silver nitrate itself will harden the albumen.

I think this might be a good place to start: The Albumen Negative Process.

This process never became very popular, and my memory is that development and/or fixing can take much longer than suggested in the article I linked above. I seem to remember other instructions that suggested developing slowly over a period of 12 hours or more, and a very long fixation step in hypo. If I remember, I'll try to look for other references, but I think you can find them yourself with google... the problem being that you'll have to filter out results for normal albumen prints and collodio-ablumen process ( albumen was sometimes used as a 'top layer' to preserve dry collodion plates). Have fun! Would love to see any results you get.

Dibbd said:

The silver nitrate itself will harden the albumen.

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Never heard that before. I'd be interested to see references?

However, albumen can be also hardened in a bath of 70% Isopropanol (Isopropyl alcohol).

There's a short thread about hardening albumen here: (there was a url link here which no longer exists)

Thanks for all the responses and pointers, folks. I've been tracking down various old books, etc, to try and get a handle on things. I think, if anything, there are too many recipes, or I haven't found a particularly definitive one (presumably because things were still rather experimental at the time, and the process was soon replaced with wet collodion).

Something that stands out is that Potassium Bromide doesn't seem to dominate as the halogen (but does with gelatin), and it's not clear to me why that would be. When it does appear, it's usually in a much smaller proportion, with Potassium Iodide being the larger proportion. Another thing is that there is rarely much explanation - the writings tend to just say things like "And here is Mr Wigglebottom's recipe, which has proved most efficacious...", and it goes straight into the ingredients and method. Why lots of Iodide and only some Bromide? What does the sugar do that isn't required in albumen paper? Acetic acid in the albumen or in the nitrate? Etc.

I find myself wondering if there are simply lots of ways to skin a cat, and that it doesn't matter all that much what approach is taken, provided the general proportions are within sensible bounds. I'm tempted to start with the proportions I used a few years ago for albumen paper, replacing the chlorides with Potassium Bromide. That would be...

100ml albumen
2g Potassium Bromide
3g Sodium Citrate (preservative)
3ml distilled water
3.5ml 190-proof alcohol (to help denature the albumen, if I remember correctly)

I still have the sensitising solution, which is...

100ml distilled water
10g Silver Nitrate
1 drop of Potassium Dichromate 7% solution (contrast enhancer, apparently)

Is there any reason to suppose that this won't, firstly, stick to the glass, and secondly, react to light in such a way as to be able to make a print from the result? Will it act like a POP, or can I develop it? (I have Gallic Acid.)

pdeeh said:

Never heard that before. I'd be interested to see references?

Click to expand...

Here you go

http://www.mrgscience.com/uploads/2/0/7/9/20796234/protein_denaturation_lab.pdf

You only need to use alcohol if you double coat with albumen and then only for the first coat.

Dibbd said:

Here you go

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Aha!
Thanks

Nomad said:

....
Something that stands out is that Potassium Bromide doesn't seem to dominate as the halogen (but does with gelatin), and it's not clear to me why that would be. When it does appear, it's usually in a much smaller proportion, with Potassium Iodide being the larger proportion....

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This is true for calotypes as well. Perhaps the people working with albumen negatives also knew about calotypes and followed the path they knew.
Or perhaps the reasons for small proportions of bromide in calotypes are also true for albumen negatives ( I have no idea )

--- Disclaimer!! The following is speculation based on calotypes. I have no idea if it will apply to your albumen negative process!!! --

In calotypes, if you increase the iodide ( usually w/ correspondingly stronger AgNO3 sensitiser ), up to a certain point the sensitivity increases. Above that point lots of problems start to occur, staining and spots and pinholes and decomposition of the gallic acid during development. It makes sense: just like salt prints and other processes, stronger solutions or double/triple coating makes more sensitive and stronger prints/negatives. More silver iodide in the paper makes more sensitive denser calotype. But just like other processes, if the solutions get too strong, you start running into various troubles. Adding bromide to the iodizing solution for a calotype makes them sensitive to green and blue-green parts of the spectrum, but again there is a limit to how far you can push it. When I tried to increase the bromide too far, I noticed loss of contrast, decreased sensitivity, and problems with staining. My calotype process is one that's right on the edge: it uses just about the most KI and KBr possible without running into lots of trouble.

Another thought:

Your recipe looks good for a printing out process, but I think you might run into trouble when you try to use it to develop a latent image. I've never tried to develop out a salt print made with bromide, but I have played a little developing out salt prints made with Cl or Cl + citrate, and at normal strength solutions they are too "touchy". They tend to turn black in the gallic right away. People who used this method ( e.g. Sutton ) used weaker solutions than for printing out. Again, whether this applies to albumen negative I have no idea. If I were you, I'd probably start with a negative albumen formula that someone claims to work first!

It sounds like fun to me experimenting with all of this. Good luck!

Thanks Ned. I hadn't thought of the effects of using stuff that's too strong, although the cost of Silver Nitrate would likely have mitigated that happening in any case. I also wasn't aware that different salts introduce sensitivity at different parts of the spectrum.

I found the following in Practical Photography On Glass & Paper (on Google Books)...

3 or 4 egg whites (assuming 100ml)
12ml Ammonium Iodide 33% solution

I have some Potassium Iodide coming in the post, and I'm tempted to substitute the Ammonium Iodide with that.

I don't know what difference ammonium vs. potassium would make ( except that to get the same amount of iodide, you'd use about a 37% solution instead of 33% ), but that sounds like a good idea to me. Then if it works, you could experiment by adding a small amount of KBr. Have fun!

Did three things tonight: some glass cleaning, made up the albumen mix, and tried a little experiment.

Glass Cleaning
The glass I'm using for this is from those clip frames for photos. I'm using 6x4" pieces just now because I'll be able to test the process with a Heath Robinson camera that I plan to make. (The eventual aim is to do 10x8, but I don't have the makings of a quick camera that size yet.) I washed the glass in warm water (a bit less than hand hot - maybe 40°) and a little dish washing detergent, then rinsed in cold tap water. I then wiped the water off using plain white cotton (curtain lining material), and then wiped down again using the cotton wetted with some IPA. A close inspection didn't reveal any streaks or smearing.

The Albumen Mix
The eventual recipe was...

15g albumen powder mixed into 100ml distilled water
4.5g Potassium Iodide (the quantity to make 12ml of 37% solution).
3g Sodium Citrate
3ml rectified spirit
12ml distilled water

The albumen was less viscous than what I got with fresh eggs when I had tried the paper process a few years ago. With everything mixed in, it was whisked with an electric mixer for about 10 minutes at the most, at which point, it had turned into a stiff white foam. This was covered with damp muslin and left to stand. About an hour later, I noticed that most of it had already liquefied, which was unexpected. I plan to leave this until tomorrow in any case.

The Little Experiment
I took the dregs of the albumen mix that was left in the beaker, and smeared some on a scrap of 100% cotton paper. While it was still wet, I put a few drops of my existing sensitiser (100ml 10% solution Silver Nitrate with a drop of 7% solution Potassium Dichromate) onto this to see what would happen. Almost immediately, there was a pale yellow precipitate. Some reading indicates that this is Silver Iodide, which I believe is a good thing.

I then darkened the room and switched on a UV lamp (one of those Black Light Blue 11W fluorescents). The area wetted with the sensitiser showed up dark - a very dark violet colour was how it looked. I then covered half of the sensitised area and left the UV lamp next to it. After about 10 minutes, it had started to darken, albeit somewhat unevenly. The colour of this in the room light looks to be brownish.

A couple of photos...



This is the test piece after about 15 minutes or so under the UV lamp. The bottom half has been covered with a little bridge of the paper so that I have a comparison. The pale yellow precipitate can be clearly seen. It's interesting that the darkening seems to be around the periphery of where the drops of Silver Nitrate landed - the middle parts are still yellow (and a stronger yellow than the middles of the shaded drops).

Here it is under the UV light...



The whole area that was wetted with the Silver Nitrate shows dark. This was the case as soon as it was wetted, before there was any visible darkening as seen in the first photo.

A further comment regarding the addition of sugar to the albumen mix. I found something in one of the old books that mentioned honey being used to help prevent cracking of the albumen film. So, not a component in the photo-sensitive aspect (which was what I wondered).

This kinda makes sense to me as a painter - honey is added to some watercolour paints that come in dry blocks (called pans), and makes them easier to use when a wet brush is applied to the pan to pick up some paint. The paint wets quicker than pans that don't have honey, and they generally feel a bit softer - easier to make an impression in a pan with the thumbnail.

I'll keep this in mind when it comes to trying some coating if cracking, peeling, etc are evident.

Sorbitol is an inexpensive humectant which prevents cracks in a variety of analog products.

PE

Sugar is a natural plasticizer for many bio-polymers. It is used as such in gelatin to make the "tissue" in carbon transfer printing. It should work the same for albumen. Honey might be even more effective (in theory) as its sugars (majority glucose and fructose) are not connected like they are in crysallized sugar (being a disaccharide of one fructose and one glucose.)

Interesting stuff...keep it coming.

After years of R&D, the photo industry settled on Sorbitol and Carbowax.

PE

Photo Engineer said:

After years of R&D, the photo industry settled on Sorbitol and Carbowax.

PE

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Yeah, but can you get them organic....

Sorbitol is a simpler, more symmetrical brethren of glucose (it is sweet too!) so I am not surprised that it would be a better plasticizer (as a reference, it has lower melting point and greater solubility than glucose) than sugar or honey. I am sure Carbowax is pretty good too if not better than all the others as it is a polymer with ether bond in its backbone that makes it highly flexible.

So by all means, if the natural remedy does not work, you got to go for the pharmaceuticals....

:Niranjan

The preliminary test looks encouraging to me.

Watching this thread with great interest! OP please keep us posted, even if the first try doesn't work!!

I will. Just not much to report right now, other than I've coated two plates with the albumen, and I'm currently cobbling together a makeshift camera.

An update, although no new results yet...

As mentioned previously, I coated two plates with the albumen mixture...



One was left to dry naturally, and the other was dried using a heat gun (resting on a surface, pointing upwards, with the back of the plate towards the air flow). Hard to see anything in the photo, but I would say that there is no obvious difference between the two. Both are coated somewhat unevenly, and both have acquired some dust. I used a pipette to put about 0.5ml of albumen on the centre of each plate and tilted it around a bit to try and get it to spread, which didn't work all that well, so I spread it to the edges and corners with a glass stirring rod. The quantity seemed to work quite well for getting the whole surface wetted with no excess. Next time, I might try applying more albumen and draining the excess.

I marked the back of each plate with 'BACK' using a sharpie pen so that I knew which side had been cleaned with IPA, and thus which side was fine to apply fingers to when holding it. (I've also numbered the plates since taking this photo.)

The main thing this weekend was to make the test camera. After some mooching around, I managed to find two cardboard boxes that were just about the right size, both to fit a plate, and because they slid into each other (they were for something that was delivered double-boxed, I think).

Here's the front...



The lens is an old Bausch & Lomb thing I picked up years ago (patented 1891, apparently). Pneumatic-damped shutter with a T setting. I reckon it's about 5" focal length. The iris blades aren't much use - they were loose in a separate bag, one is missing, one is bent, and one has lost one of the little pins that make it move when the aperture is adjusted. The elements unscrew, so I made a stop for it...



It's about 5.7mm diameter, so about f/22. The length of the inner box is about right for hyperfocal distance at this aperture. It slides into the outer box and presses against a plate at the back...



That's a ground glass that was made for practice, and to check that the fixed focus was about right before fitting the stop. Here it is in all its glory...



The velvet around the inner box is a light seal. Before I fitted the bit of board holding the lens, I looked through the square hole in the front of the box and could see leaks coming in between the two boxes, and the velvet removed them. I might paint the inside black if the inclination takes me.

The main purpose of the camera is to try and replicate what might happen with the eventual 10x8 setup. I'm not too bothered about image quality (the plate is probably not terribly perpendicular to the lens axis), but I will need to characterise, and possibly adjust, the process in terms of sensitivity, and that will be done better if the light is passing through a lens (or being attenuated by the glass in the lens if it's UV). This should give more relevant results than something like contact printing a 5x4 negative onto a plate using a UV lamp.

In other news, I made up a 1% solution of Gallic Acid, and 15% Sodium Thiosulphate. I also had a play with a glass dish like that in the photo of the plates, to see how much liquid it takes cover a plate, and find out what it's like pouring the liquid out into a beaker. Turns out that 100ml will comfortably cover a plate, and pouring out up to 200ml into a beaker seems to work spill-free. Since my sensitiser is in a 100ml bottle, I'm tempted to sensitise the plates by immersing them rather than faffing about with trying to coat with a squeegee per my other thread (haven't made a mould yet). If nothing else, I'll find out how the Silver Nitrate gets affected when it presumably gets contaminated with the stuff in the albumen.

I also picked up some honey. I couldn't find the Sorbitol shop on my way home from work, but I did find the honey shop. For no particular reason, I chose acacia honey, probably because it was quite light in colour, and maybe-possibly seemed a little less viscous than some of the others. Turns out that it's meant to dissolve quite well compared to other honeys, so perhaps I made a good choice unwittingly. Not added to the albumen, but will try it if I get cracking or delamination.