View Full Version : Dry plate newbie questions

07-04-2011, 01:53 AM
Hi, i've been wanting to do plate photography, even asked a few questions here. At first I was thinking of doing wet plate, but I think it would be simpler if I started dry plate first.

I'm planning to use this Kevin Klein recipe from the light farm due to the simplicity.
A few question though,
1. How I can make the 0,2 hypo solution?
2. If I can't find thymol is it possible to replace or discard it completely?
3. For developing the most available developer here are: a local clone of D76 and home brewed parodinal can either be used?

Best regards,


07-04-2011, 12:08 PM
Hi Dave,

Congratulations! You're going to be having a lot of fun.

Re #1: % solutions are easy to make if you start from the beginning in your thinking. 1% = 1/100. 2% = 2/100. 0.2% = 0.2/100. For water, g = ml. The only 'problem' that comes up is that it is very hard to accurately weigh 0.2 grams with the scales that most of us own. So, use 2 grams sodium thiosulphate in 1000 ml water, (you're just moving both decimal points one to the right) or 1 gram in 500 ml, if you really trust your scale, but dry hypo is so cheap that it doesn't seem worth it. Also, in my experience, at this big a volume to small dilution, it's not necessary to worry that the total final solution should be exactly 1 liter -- just be consistent.

re #2: you don't need thymol if you keep the emulsion refrigerated until coating and if you use it within a couple of weeks of making.

re #3: just about any developer in the general D76 'family' will work fine.

Best of luck and fun!

07-04-2011, 09:28 PM
Hi Denise,
I was hoping you'll be the one giving some light on this :) I want to try your recipe but I think better to try the most simple first.
For now I'm planning on contact printing on commercial paper first, and then I hope I'll be making my own paper. But I am very interested in your article on enlarging home made paper as in my knowledge you need UV from the sun to expose the paper, would love it if you can give more detail. This is of course for later, as at the moment I don't have the enlarger that is big enough for my plate size :)

07-05-2011, 11:21 AM
Hi Dave,

Starting with Kevin's recipe is a great way to get your feet wet. It my opinion (perhaps repeated too often ) that emulsion making may be the only craft I know where so many beginners want to start at the end!

Re recipes: It's been one thing after another, but every roadblock I can see to getting a bunch of new recipes posted on TLF in the next few months is getting knocked down. Start simple now, and you'll be well on your way to more 'advanced' work. Pop back here with any questions. I'm going be trying to check APUG once a day (usually morning, PST.)


07-05-2011, 11:44 AM
Thanks Denise, i'm still waiting for a new bellow for the half plate camera, hopefully I can start coating soon :)

More questions is coming for sure :D

Best regards,


07-05-2011, 12:13 PM
Excellent! Maybe you'll help expand this forum beyond wet plate and camera collection (as nice as both of those things are :))

I think it's high time for a dry plate photography movement and this seems like a great place to aggregate the field into its whole -- emulsions, cameras, shooting and processing.

07-06-2011, 09:52 AM
Another question I want to ask Kevin's recipe states photographic grade gelatin, im not sure I can get that here. I see in other recipes it is ok to swap it with food grade gelatine, cam I do that on this recipe?



07-06-2011, 10:30 AM
Yes, with a caveat. Photographic grade gelatin is a constant. The bloom (hardness) number is 250 and it's been purified of most of the extra components that can influence an emulsion -- for the better as well as for the worse. Mostly, it's just a matter of predictability, rather than good or bad. The right 'extras' were valued by the early emulsion makers, but 'food grade' covers a lot of territory. Knox brand plain has a bloom of 225, Gold leaf is ~200, and Silver leaf is ~160. Harder isn't necessarily better, but you have to take a softer emulsion into consideration through the processing chain. You may not need as much hypo solution if you find the right gelatin, so keep your eyes open for that, and take good notes. I've been adding a couple of grams of Knox to my favorite recipe, with the bulk photo grade.

07-06-2011, 10:58 AM
That is exactly what will prove To be the most challenging aspect of my effort. Most of the Tools and ingredients will not be easy even impossible to get so most of them will be improvised, I just tried to make a coating rod from glass tubes used for aquarium lighting. Same problem on the gelatine the most available does not make the bloom numbers. But I guess I'll just try it out :)

07-06-2011, 11:15 AM
Improvisation can be part of the fun. It certainly is a challenge. I did a lot of it when I was getting started (haven't really quit -- I'm a garage shop inventor at heart) but I suspect you're going to be in for a lot more than I was :). You should be able to get bloom numbers from the manufacturers. Find a website contact number or email. Bloom numbers are as important to cooks as they are to photographers.

I'll inflict you with an opinion, though. Given the cost of silver nitrate, the cost of all other ingredients falls relatively to free. I'd invest in the extra shipping costs to get good materials as you get started. It will more than pay off.

07-07-2011, 01:31 PM
A note on food grade gelatin. If you do go that route, order it in bulk (i.e one big bag). Divide it among many small plastic bags, sealed tight. Keep those stored cool and dry, and then open one bag at a time. Photo grade gelatin manufacture and quality control is rigorously controlled. Food grade is controlled for bloom and safety, but the other constituents (that don't matter at all for food use but can have a big effect on emulsion making) can change from lot to lot. If you buy enough to last for a long time, you'll quickly learn its characteristics and eliminate gelatin as a capricious, and potentially confusing variable.

07-15-2011, 05:55 AM
Another question on Kevin Emulsion recipe, There is also a possibility that I may can't get the bromide. Reading the darkroom cook book they are restrainers and potassium iodide can be a replacement with recalculations. Any chance of doing that on dry plate?

07-15-2011, 08:09 AM
Unfortunately, the answer is no. Potassium bromide (KBr) serves a different purpose in emulsions than as an ingredient in emulsion making. There are three halides practically useable in emulsions -- chloride, bromide, and iodide. Cl and Br can stand alone, or be combined. Either or both can be combined with a miniscule amount of iodide, but iodide doesn't work as a stand alone halide.

Bromide, usually with a tiny bit of iodide, is the classic dry plate recipe. Kevin leaves out the iodide and does great (maybe a tad slower) but Chris Patton uses sea water, which is sodium chloride -- table salt. If you can't get potassium bromide, you might go that way. Get a brand with no additives at all.


07-15-2011, 08:28 AM
What will be the difference if using table salt? That does sound easier :)
Talking about chlpride, How About ammonium chloride? Does that work? I have some from a fixer formula.

07-15-2011, 09:01 AM
All things being equal, the Cl emulsion will be slower with greater contrast. You might also get a bit of peppering (spontaneously developed grain.) Chris's goal is to go as natural and close to the ocean as possible. He celebrates the slowness of the emulsion. He figures (and I agree) that there are fantastic, fast, panchromatic films commercially available. Recreating them is not his windmill. He loves the effects that come from slowness and colorblindness.

Re ammonium chloride: I don't know. My philosophy is 'give it a try' (maybe after you try sodium chloride.) Use a little less. The reacting amount of KBr to one part silver nitrate is 0.7. NH4Cl and NaCl are about 0.4. The advantage of using an ammonium version of a given halide is that's a mild silver solvent. You'll be less likely to get peppering. Ammonium chloride is the usual halide in printing-out papers, but usually with silver in excess and with an organic acid, so I can't see that you'll get funky negatives with a dry plate recipe's ingredients and proportions.

Luck and fun :)

07-15-2011, 09:20 AM
Okay one more question on the halide factor, if I did use the ammonium chloride, you suggested less should be used compared to the sodium chloride?
Still waiting for the bellows for my camera though. Hopefully I can try this soon. :)

07-15-2011, 09:36 AM
No, sorry if I was confusing -- typo (never type before a.m. coffee!) 'Am'Cl and NaCl have about the same reacting proportions. If you're substituting into Chris's recipe, use the same. If you're substituting into Kevin's, use about a third less than for KBr.

Hope your bellows come soon!

07-18-2011, 08:29 AM
oops. In post #13 I typo'ed (again! sheesh.) Fortunately, it's obvious, but to be accurate, "...KBr serves a different purpose in developers than as an ingredient in emulsion making."

I think I counted a half dozen typos in the internet newspapers just this morning. Do you suppose it's something contagious? are we getting lazy, or is there something to this 'brains being rewired' stuff? Don't mean this to be a topic here, but it does give one pause.

07-18-2011, 08:58 AM
Luckily I understand what you mean :)
Just read a article on the net yesterday that memories of telephone numbers is declining with the invention of mobile phone with it's phone book. I guess that also can be correlated with all the auto correct functions making us lazy to proof read before publishing?
Of course I can use the excuse of not being a native speaker of English :)