Fresh dry plates in a variety of sizes

[Nodda Duma]

Here's a plate that is sized for use in a 35mm camera. I've started using scrap glass to make these for emulsion testing, since my Nikon has a faster lens and is easier to duck out of the darkroom to snap a photo as soon as the coating dries.

I took the photo last week, but just now got around to developing it. I used a Nikon F3HP, which goes down to ISO 12, and then overexposed an additional 1 1/3 stop. So I shot it at maybe ISO 4 if the meter was correct. I thought that was interesting.

This plate is made from the same batch (#004) that most of you guys ordered, but with a better subbing layer that I'm testing.

I developed it for 5 minutes in HC-110 dil B at 67 degrees. Indicator stop bath. Fixed in hardening fixer. That's all my usual process, but then I washed the plate throughout a range of temps.

Once it dries I'll scan it in to look at the grain.



-Jason

[Nodda Duma]

Scanned image.

According to my calculations, I exposed this at about ISO 6. So I'm going to do some testing to see if the emulsion can be run faster than the ISO 2 that I baselined in an earlier batch. Maybe it is faster than I expected! I'd be interested to hear results from any of you all who want to do some similar testing.

[Nodda Duma]

11"x14" plates packed up and ready to go.

[William Whitaker]

Now that's tantalizing!
Is this a harbinger of things to come?

[Conrad . Marvin]

This looks great, I'm sure that you will be quite busy pouring emulsions! I was making dry plates for a few years before I moved and don't yet have a darkroom. It is pretty tricky to get consistent results and even more difficult to find glass that is thin enough. Anyway, great to see that others are also interested in the process and "look" that only comes with dry plate emulsions.
Thanks!

[Nodda Duma]

This looks great, I'm sure that you will be quite busy pouring emulsions! I was making dry plates for a few years before I moved and don't yet have a darkroom. It is pretty tricky to get consistent results and even more difficult to find glass that is thin enough. Anyway, great to see that others are also interested in the process and "look" that only comes with dry plate emulsions.
Thanks!

Thanks, yes.. it's taken a couple years to perfect my technique and source the right glass (which I've done). Results have been consistent for several emulsion batches now... I wouldn't have considered offering them for sale if they weren't coming out awesome.

-Jason

[Randy]

Jason, perhaps a stupid question - can your dry-plate mix be coated onto aluminum for making "dry tintypes".

[Nodda Duma]

Jason, perhaps a stupid question - can your dry-plate mix be coated onto aluminum for making "dry tintypes".

Interesting. I've never considered it. I'd have to test. I would think it depends on how well the emulsion adheres to the Al2O3 layer that is always present on aluminum, and the state that layer is in (i.e. surface prep).

I have a block of machined flat aluminum laying around that I could try on. When I do, I'll report the results.

[Randy]

Jason, doesn't the aluminum surface for "tintypes" have to be blackened for the developed negative image to appear positive in the finished product? If so, I guess that might affect your test.

[Pere Casals]

To apply photoemulsion to metal plates just prepare the metallic surface with single coat layer of polyurethane to obtain a surface for the emulsion to adhere well.

Surface has to be hydrophile, if not instead a layer you obtain drops on the surface.

A good practice is once the polyurethane is dry, to apply an undercotat of Type R gelatin (ADOX COLLOIDA R. or the like) or simply food gelatin, and once dried you apply the photo emulsion.

That intermediate gelatin R layer can be omited... it requires a drying time and a it is a new chance to take dust.


Photo emulsion can be applied to a wide range of of surfaces.

With absorbent materials like fabric, papers or wood normally a pre-coat of Type R gelatin is done to save silver rich photo emulsion.

Type P gelatin is used to mix the emulsion, this kind of gelatin may contain some compounds that may be benefical for emulsion speed. Type R is used for under or over coating.

You can also apply the photo emulsion to mylar sheets to obtain film. This is kindly described by Denise Ross in The Light Farm. She tells what kind of mylar sheets are hydrophile and suitable to be coated with P-E, some sheets are lipophile and coating would be very bad, because forming drops.

The coated metal plate can be used as if it was print paper...