Quote Originally Posted by ueli View Post
A few questions I have:
1. What is the optimal time for the silver nitrate bath? I've done four minutes each time, but maybe there's a problem here? I have very little silver nitrate to work with, I only ordered 10g because its so expensive, so my bath barely submerses the plate without constant movement of the container.
2. Am I supposed to be washing the plate off after the silver bath? I haven't done so at all, and even though I tap the plate a bit over the bath to get most of the liquid off, its still wet with a little silver nitrate mixture when I put it into the camera and during the exposure.
3. How long is the fixer stage supposed to last? I have been putting the plate into the developer for about 35 seconds (it says 30-40 seconds at 70°F on the bottle), washing it off, then putting it into the fixer for anywhere from 15 seconds to a minute. I have read that it is supposed to be until the image appears, but of course none do.

Those are about all the questions I can think of at this stage, I know there are calculators for exposure time, but they aren't very useful for me since I have no way to measure light level or any specifications for the lens I am using (ridiculous I know, but that's what a mysterious $7 eBay lens gets you).

Once again, any comments, advice, or anything to know I'm not typing into a void would be much appreciated . Also, would this be better posted as a separate thread about my cardboard adventure? I'm afraid to violate any unspecified etiquette, I have only ever lurked on forums before.
1) The rule of thumb is around 3 minutes at 20C - longer if it's colder, can go shorter if it's hotter. In general it doesn't really matter if you leave it in longer. Agitating it the way you are will speed up the sensitising.

Something I didn't see you mention is whether you iodised your bath before using it - you need to put a glass plate coated in collodion in it overnight. I may be misremembering this, but I think the reason is because otherwise an unseasoned bath will suck all the iodides out of the collodion on the plate you're taking an image on, and you won't get much.

Because you are using such a small bath I would not use a whole plate though, I'd coat a small piece of glass (maybe 25cm2 or less). Don't use trophy aluminium because having it in your bath overnight will do bad things to it.

I know silver nitrate is expensive but you are making it extra difficult for yourself using such a small bath relative to the size of plate. Any problems with your bath such as excess solvents, contamination, or particulate matter are going to be magnified and immediately apparent, there will be much less margin for error. You'll also find it harder to get consistent results with each plate taking up a comparatively greater amount of the available silver, meaning you'll need to maintain and replenish it more often.

You can build a vertical tank for 4x5 out of a memo water bottle (hacksaw off the top), and some cardboard and duct tape for lightproofing - it's what I've used for years.

2. On the contrary, you want to dry it off as best you can. Put each edge down on a paper towel and let that wick away a bit of the remaining silver nitrate solution, then dry the back. The less silver nitrate floating around in your holder/camera, the less likely you'll see artefacts from contamination. However, washing/not washing it would not lead to the global failures you're seeing in your plates.

3. Fixer depends on how many plates you've run through it already (some people like to use it one-shot, personally I don't want to deal with disposing of that much fixer). I use sodium thiosulfate at around 20% concentration by volume and a plate typically clears in 10-60s or so depending on how much I've run through it that day and how recently I've topped it off with fresh stuff. At any rate it's not really possible to overfix with sodium or ammonium thiosulfate, so that won't be your problem.

Collodion is notoriously hard to meter for due to how the chemistry ages and how it perceives light differently from our eye/a standard meter, but that doesn't mean a meter isn't useful.

If you had a normal film holder (or found a way to integrate a darkslide into your camera), you could do a test plate where you push the dark slide in at 20% increments for exposures of 2 (all the way out), 2, 4, 8, and 16s (final 20%). The resulting plate will show you what exposures look like at 2, 4, 8, 16, and 32s. If you take note of the EV values when you shoot your plate, you can then adjust as the light changes. Unless I was shooting the previous day and have readings to go off of, I start every shoot by doing this. Today I got an exposure of 5s @ f/16 with a meter reading of 12EV in the shade, and as the sun came out (and later was hidden by clouds) I could adjust as I went. Trying to develop by inspection is something everyone sees the experts doing in YouTube videos and tries to emulate, but it just adds another unecessary variable to the process and creates more problems for most people starting out. You're doing the right thing by holding development time constant, stick with the instructions.

I have a feeling that lens probably lets in a fair bit of light (and doesn't have a way to close down the aperture and let in less), so in full sunlight you may need to use shorter increments than I described above, like maybe 1/2s, 1/2s, 1s, 2s, 4s.

If you'd like some free reading, Will Dunnaway's widow has posted his collodion handbook online for free: https://www.alternativephotography.c...Plate7-web.pdf

Christopher James (who wrote the Book of Alternative Processes) has a chapter on wet plate, which also happens to be one of the ones he offers for free as a sample: https://static1.squarespace.com/stat...on-Process.pdf

But definitely keep posting your results and questions here too!