New chef from Italy, first result and troubleshooting

Hello,

I'm Filippo from Italy and I just started making homemade dry plates following Kevin Klein recipe found on The Light Farm (I'm already experienced with LF film & wet plate collodion)

The first results are encouraging, this 4x5 plate is exposed at 3 iso with the continuous light system which I use for wet plate:

First homemade silver gelatin emulsion dryplate experiments by Dead Link Removed, on Flickr

I tried to pour a thick emulsion to get enough density for alt printing (mainly albumen and carbon transfer) but I encountered two main problems:

1) Emulsion blistering: I found no evident bubbles when I poured the emulsion on the plate but they showed when I developed it in Dektol 1+1 at 20°C. In the carbon transfer process blistering is caused by microbubbles expanding when developing the image in the warm water (40°C) so I guess I have a similar problem even if the temperature is much lower. You can see the white spots caused by the dryied blisters in the plate. I'll try to add some drops of alcohol when remelting the emulsion and keep the plate warmer prior to pour.

2) The emulsion dried a lot thicker in the middle than on the edges (you can see the difference of density in the image i posted). I had this on all the six plated I poured, all with a similar pattern. Atfter pouring the plates I rested them on a leveled marble sheet to set the emulsion, then I placed them (vertically) in a plate rack inside a light tight box. In my experience with collodion I usually get a thicker layer on the edges where I pour off the excess and not in the center...here I have the exact opposite. The "wet" emulsion was apparently spread even, the difference of thickness showed only when dry...so I don't have a clue

As a side note, in the recipe there is no hardener in the emulsion, just the suggestion of a hardening fixer. I haven't added any hardener and I haven't had any adhesion or emulsion scratching problems but I'm wondering if adding an hardener could solve one or both of my problems.

Thanks!

Hi! Filippo. Welcome! Lovely image and a really quite good looking plate.

Thin edges are a characteristic of the 'traditional' pour method. The first dry plates were almost all poured by photographers who were coming from wet plate. They naturally brought their hard-won skills with them. The thin edges basically act like vignetting. It can be very effective with a lot of images. If you know about what your plates will look like, you can make sure to compose the image well away from the edges and then crop the final print, or leave the distinctiveness as part of the craft.

If you don't want thin edges, you can go next-gen on plate coating. http://www.thelightfarm.com/cgi-bin/htmltutgen.py?content=06Mar2013

re blistering: I don't use hardener. The thickness of the emulsion, the temperature of the processing solutions, and how gentle you handle the plates during processing are all more influential on blistering than hardener. You can try one or more of a couple of different things.

1) Drop your processing temperature down a couple of degrees and make sure that every solution, including wash water is within a degree or two of the same temperature. Hardening chemistry was necessary in days of yore before cold water was always possible. We are very lucky that way! If your darkroom gets too warm, you can set the processing trays in larger trays of water with an ice cube or two. I had to do this for years in my Phoenix, Arizona darkroom, and that was with commercial film and paper.

2) Increase the temperature of the emulsion at pouring to get a slightly thinner coat. With enough exposure and good development you should get a vigorous enough plate for albumen and carbon. http://thelightfarm.com/cgi-bin/htmlsectiongen.py?chapter=Chapter4 (go to the fourth section of the page, 'Matching Technique to Process').

3) Make sure to handle the plates during processing from the bottom and not the edges. If your trays have ridges or dimples, you should be able to get your fingers under the plate to lift it.

4) Make sure your plates are very clean before coating.


Good luck! I am really looking forward to seeing more of your work.
d

Nice results, did you use an acidic stop bath which sometimes has some unwanted effects on non hardened emulsions ?

Thank you for the tips! I thought I had read all articles on your site but I missed this...nice technique, I was thinking to build a coating well but I'll definitely try the spoon first!

And no, I didn't use an acid stop, just plain water. The blisters appeared as soon as I put the plate in the developing tray and all the chemicals were at 20°C, which was also the room temperature.

I'll let you know how it goes with the next plates

MDR said:

Nice results, did you use an acidic stop bath which sometimes has some unwanted effects on non hardened emulsions ?

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Good thought. I said "Aha!" to myself when I read it -- until I read Filippo's post. Now I'm really puzzled. I thought I'd managed to stumble on everything that can possibly go sideways for an emulsion, but I've never had blistering immediately after a plate hits the developer.

Filippo: Do keep us informed! I love a good mystery . Could it be that you have teeny, tiny bubbles dried within the emulsion that only showed when the emulsion got wet? Those can happen from accidentally whipping air into the emulsion during the make. If your emulsion went down thick enough to embed them, they might very well be invisible. Just a thought.

dwross said:

Filippo: Do keep us informed! I love a good mystery . Could it be that you have teeny, tiny bubbles dried within the emulsion that only showed when the emulsion got wet? Those can happen from accidentally whipping air into the emulsion during the make. If your emulsion went down thick enough to embed them, they might very well be invisible. Just a thought.

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Yes, this is my main hypotesis. The same thing can happen when making carbon glop (gelatin with pigment) and it's resolved adding isopropyl alchool to the glop and let it rest a bit before pouring, to allow the microbubbles emerge to the surface and pop.

In the next coating run I'll try to add a few drops of alchool (isopropyl or 190 proof?) and let the emulsion rest a bit before coating the plates.

Very interesting. With your wet plate and carbon expertise, you will be making huge contributions to our craft.

I've never used isopropyl in an emulsion. Always pure 190 ethanol (or excellent plain vodka, taking the extra water into consideration.) Isopropyl might work fine, but I've never had the courage to try it as long as I can get good hooch (Everclear) in my state .

Along with your other tests, you might try letting the emulsion set up, and then melt it to coating temperature without stirring. That should drive out a lot of the microbubbles.

Blistering can be caused by the lack of hardener in the emulsion. Use 10% chrome alum in the emulsion at the rate of about 5 ml for every 100 - 200 ml of emulsion. If you wish to avoid this, use a 10% chrome alum pre-hardener for 5 - 10 mins at 20C and then a 5 min wash before developing. This latter is less effective but it works.

Just be careful. Often Dektol is not the best developer for plates.

PE

Photo Engineer said:

Blistering can be caused by the lack of hardener in the emulsion. Use 10% chrome alum in the emulsion at the rate of about 5 ml for every 100 - 200 ml of emulsion. If you wish to avoid this, use a 10% chrome alum pre-hardener for 5 - 10 mins at 20C and then a 5 min wash before developing. This latter is less effective but it works.

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I just made a test with a previously coated plate and the hardening bath reduced the blistering a lot but it's still present. Since I have about 80ml of the first batch of emulsion in the refrigerator, should I add the hardener when I'll remelt it for coating or when I'll make the next batch of emulsion?

Photo Engineer said:

Just be careful. Often Dektol is not the best developer for plates.

PE

Click to expand...

I used Dektol because I found it in several emulsion tutorials (along with D-49), could you suggest me something better? I aim for a DR of about 2.0 for albument prints (sorry if it's a frequentyl asked question, I'm searching plate developers formulas on apug but the search engine gives a lot of unrelated results, mainly about wet plate)

Thanks!

towards the bottom of this page
Dead Link Removed
you will find a recipe for a dryplate developer ( kodak d-49 )
the article also says you won't have trouble using dektol and gives instructions on using it best.

have fun !
john

At the present time, GEH uses Dektol for experiments with dry plates along with the D-49, however, here is the question.... Would you use Dektol routinely with your negatives? I think not. No, D76 is probably better because there is nothing present to form gas bubbles in case the emulsion is a bit acidic. D76 is also good because of its superior image quality for negatives.

Add the chrome alum just before coating and allow the coatings to dry normally. This can be used with a chrome alum pre-hardener.

However, both Nick and Mark coat plates routinely with no bubbling. So, this may indicate a pH problem or a coating thickness problem or both.

The pH should be near neutral.

PE

at the risk of causing trouble...

i since september, have begun to routinely process my film in dektol, and i routinely processed my film in ansco130 for more than 15 years before that.
i found the film processed in dektol ( and ansco130 ) to be better than most any other "film developer" i have used.
and for years i would process my hand coated dry plates in dektol, 1: 2 never a problem ( between 1986-1999 ) then ansco130, 1:2 (same results 1999-2009-10))
over the past 5-6 years, i changed though i process my dry plates in 2 developers side by side ... one is hard working
and if the image develops too fast and hard i put it into coffee based developer with dektol ( or ansco 130 ) mixed in .
i do the same for silver gelatin ambrotypes and tintypes, and regular old photo paper ( hand coated or store bought )
as well, start it in 1 developer and when it starts, move it to the other one.

i guess different strokes for different folks.