Problem developing plates

[Krokodul]

Hi all,

I’ve run into a new problem that hopefully someone can shed some light on. My latest few plates all have really big image particles and droplets of mercury in the shadow areas. I can’t seem to remedy this problem. I cut my developing time to 2 1/2 minutes at 90°C and also tried lowering the temperature of my mercury bath to 70°C but it didn’t really make a difference. I feel a bit lost, and was wondering if you guys could help me understand what’s going on? I’ve attached a photo showing the Daguerreotype through a jeweler’s loupe.

Daniel

[CasedImage]

Your development time is too hot and too quick, try extending your development time as well as dropping your temp to 70 deg C, you need to find a point of development time/temp for the sensitization and exposure of your plates that doesn’t rely on over development. Nice looking plates otherwise, congrats.

www.CasedImage.com

[Pobboravsky]

Hi Daniel and Alan,

The proper dev’g time-temperature depends to some extent upon the design of the mercurizer. Early on, when I was working with quarter-plates I successfully dev’d at 90 deg. C for 75 seconds without frosting in the shadows.

In 1989, when Grant Romer and I made d-types in Paris we developed 5×7-inch plates for 6 or 7 minutes at 80 deg. C. This was done with a mercurizer of a different design.

However, either one of the above two Time-Temps. is a good starting point for your dev’g box, Daniel.

For the benefit of those starting out it would be interesting to list the good time-temp used by workers.

Good luck,

Irv

[Krokodul]

Hi Alan and Irv,

I really appreciate your suggestions. Thank you very much! So this it what mercury frosting looks like? The weird thing is that the problem started only recently. I developed several plates for 3 minutes at 90 deg. C without frosting before. I suppose it could be because I changed the concentration of my bromine water? There’s another question that’s been bugging me: Do you try to keep the temperature constant during development or do you turn off the heat once the mercury reaches the desired temperature? I’m using a small alcohol lamp that I put out as soon the pot is up to temperature.

Thanks again,

Daniel

[Pobboravsky]

Some of the 19th century daguerreian literature mentions putting out the flame of the alcohol lamp once the mercury reaches the aim temperature. I have no experience doing that. However, continue to do that; you don’t want to change in mid stream. Mike Robinson jokes that if you get good results while wearing green socks, wear them every time you make daguerreotypes.

The time-temperature values I gave assume that the thermometer is measuring the temp. of the mercury itself.

Good luck,

Irv

In my experience wearing brown socks always ends in failure.

[newone2010]

I meet same questions now.As my English is so poor,I always understand what you mentioned with mistakes.So I always made mistakes in making dags.

The mercury time:

Does it depend on devloping time/temprature and the balance of Br-I?

Different balance of Br-I needs different Mercury time?

Looking forward for your reply.

[Author]

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