Wet Collodion Failure

[Marc Leest]

Today we tried to make our first wet plate negative. Total failure however. The plate came milky white with some dark blotches out of the developer, with absolutely no trace of an image. Exposure was 15 minutes.
Any idea's what could have caused this ?


potassiumiodide+potassiunbromide used as halides,
9% silvernitrate solution
ferroussulphate as developer
sodiumthiosulphate as fixer


thx, Marc

 

[SuzanneR]

I'm no expert, but I did a workshop this last summer, and our exposure times were anywhere from 3 to 15 seconds in the sun, not minutes. Might it have been completely overexposed?

 

[TheFlyingCamera]

Sounds like total overexposure to me too.

 

[gr82bart]

Yeah, even with the enlarger method that I use, I don't think I've made anything over 30 seconds exposure.

Regards, Art.

 

[RobertP]

15 minutes and you're to the point of your collodion drying out.

 

[Marc Leest]

But at overexposure, the plate would be black, not mainly white (expected clear ..?) with some black nonimage stains. The reason to use 15 min that a first try of 15 SECONDS yielded in the same result.

 

[SuzanneR]

What time of day were you shooting? When it's too early or too late, it can be harder to make exposures. Also, when we had an overexposed plate, it looked lighter, not darker. Unless you are using clear glass, I would think. One really dumb mistake I made that yielded no picture... not taking the dark slide out. D'oh!!

Although you may already know about it, John Coffer's "Doer's Guide" is an excellent resource with DVD's. Just google him to see about getting a copy. The DVD is invaluable.

 

[gr82bart]

Although you may already know about it, John Coffer's "Doer's Guide" is an excellent resource with DVD's. Just google him to see about getting a copy. The DVD is invaluable.

Double that advice. Worth every penny.

Regards, Art.

 

[TheFlyingCamera]

But at overexposure, the plate would be black, not mainly white (expected clear ..?) with some black nonimage stains. The reason to use 15 min that a first try of 15 SECONDS yielded in the same result.

Mark- you're thinking like making a print - even if you're using an enlarger to make a collodion exposure, you're making a negative. The color of the plate behind it is what makes the image appear black. If the collodion goes completely white, you've overexposed it. If you're getting a totally fogged plate at 15 seconds, try cutting it back to 5 and see.

Another possible source of fog could be from your safelight - how bright is it, and what color is it? It needs to be a RED safelight. Are you at any point while the plate is wet handling it in room light? You need to keep the plate in safelight conditions until you have finished development.

 

[scootermm]

The collodion dried out.
My collodion batch is old and red (extremely slow) and recently exp are around 2-3mins. That sometimes causes dried out areas.

15mins, your plate completely dried out I bet.

 

[Marc Leest]

Could it be the developer ? It seems that we used Ferric Sulphate (Fe2(SO4) 3) instead of Ferrous Sulphate FeSO4. The stuff we used was pale yellow instead of light green crystals.

tx, Marc

 

[scootermm]

marc... again... 15mins is a LONG time. Its called wet plate collodion, because the plate needs to stay "wet" (as in it needs to remain damp and moist).
I've done 8mins exposures where 3/4 of the plate is blank because it dried out.
Wet plate shooters use those HUGE brass lenses for more than just the swirly bokeh they give, they provide wide open apertures to make the exposure times manageable.
Before messing with everything else, this seems like the most obvious culprit. I'd try a wider aperture, more sunlight, etc to get some shorter exposure times.

 

[Marc Leest]

marc... again... 15mins is a LONG time. Its called wet plate collodion, because the plate needs to stay "wet" (as in it needs to remain damp and moist).
I've done 8mins exposures where 3/4 of the plate is blank because it dried out.
Wet plate shooters use those HUGE brass lenses for more than just the swirly bokeh they give, they provide wide open apertures to make the exposure times manageable.
Before messing with everything else, this seems like the most obvious culprit. I'd try a wider aperture, more sunlight, etc to get some shorter exposure times.

We will try of course shorter exposure times 1-2-3 secs as advised, we will do this when our class gathers next time. Just checking whether everything else might influence the process.
We use a Rodenstock 210 Gerogon on an vintage wooden process camera.
I 'll keep you informed.
thx, Marc

 

[smieglitz]

Here's an ambrotype showing evidence of drying out opposite the pour-off corner.

The plate was exposed roughly 2 minutes after it came out of the silver tank. Exposure was about 8 seconds in the camera in open shade IIRC. Developed in ferrous sulfate roughly 45 seconds after the camera exposure was made. So, from pouring through sensitizing, exposure and developing, the elapsed time was about 7 minutes total and the plate was still partially dried out. This one was made with sodium salts which tend to dry quicker than other salts such as potassium bromide and potassium iodide.

Joe

 

[smieglitz]

Could it be the developer ? It seems that we used Ferric Sulphate (Fe2(SO4) 3) instead of Ferrous Sulphate FeSO4. The stuff we used was pale yellow instead of light green crystals.

tx, Marc

Ferrous sulfate is the developer. It is light green in color in powdered form and tends to age to an orange sherry color when mixed with the water, acetic acid, and alcohol.

Joe

 

[Marc Leest]

So, we did a new test, and the results were much better, albeit not great. We got an faint image (exposure was 10 sec), but we had / have some problems with the sensitized collodion, while being in the silvernitrate bath, the collodion came loose from the plate, and it was not possible to continue (got an headache from the ether/alcohol vapours )

 

[bill schwab]

..the collodion came loose from the plate, and it was not possible to continue

Are you cleaning your glass thouroughly? Roughing the edges of the glass? Subbing the edges with albumen? Using alcohol as a replacement for ether? There are many things that can contribute to lifting.