Collodion back on track

Collodion back on track

  • 19th July 2015
  • Blog

After hours of messing about in the darkness of my laboratory, I am still stuck with some wet plate issues.  The over active collodion issue is not fully resolved yet, but I suspect its was mainly new collodion combined with hot weather thats made image making very difficult.

For the last couple of months my wetplates have been unmanageably foggy and develop way too fast. It appears the issue was new collodion + hot weather = over sensitivity and fogging images. Hell, I didn’t even think its that hot but my collodion certainly seems to prefer the deeper winter months.

To try to combat the overactive collodion you need a weaker developer. The normal procedure is to add more acid that restrains the power of the developer but I personally found the acid not as effective as I expected. I did find diluting the developer 1:2 with water made things much more manageable, but still I found myself bordering on fogged images.

Cooling the developer/water down in hot weather to manage development is only marginally effective In fact it was really not that effective at all. I think it may help a little in combination with a diluted developer. The real control came when I tried adding sugar to the developer. Sugar restrains the developer by physically slowing down the flow of developer on the plate by the magic power of viscosity.

But heres the catch, even with all this bloody customised developer mixing to get the images to work, they still develop too fast and have a tendency to fog. I have to at least dilute the sugar developer 1:2 with distilled water. and then the next issue appears – Blueness.

My images have blue tinges all over and the parts that are not blue are more yellow than normal. My plates are looking like split toned prints.  Now there are lots of causes for blue toned images but the other day I did read that one reason is very under developed images. In order to get the development under control I have diluted the developer so much that its now too dilute and causing blue and yellow tones.

With close inspection these blue toned tintypes have lots of shadow details. So if I’m under developing and still getting lots of shadow details the reason should of been obvious to me. My images are overexposed.

The following week I drastically decreased my exposure times and tried and achieve the normal development time of about 15 seconds. It just about worked. I am now fairly confident the issue is collodion related and also that I can now learn to spot this in future and control the process to get manageable results.

Whilst I’ve been trying to get to grips with collodion in hot weather I have shot more plates than usual and came into more issues than ever before. Ive come some way to resolving a lot of them. Heres some of the findings.

How to quickly combat fog.
This is something that drastically speeded up my troubleshooting; don’t bother exposing the image. Get a plate ready to shoot, let it sit for a minute or so and then develop it for about 20 seconds, then fix. If you get any fog its really easy to see. Next time dilute the develop in half with water and try again, if that fails cut it again. You could also try adding acid, a different developer mix, anything.

With unexposed images fog is clear and easy to spot on the black plate and also its much faster then exposing images for each troubleshooting experiment. I also found I wasn’t spreading the developer evenly over the plate as one half the plate was more fogged than the other. You can learn a lot from trying this if you run into chemical problems. It can also help to give you clues to if the fog is darkroom or camera based light leak

Never time the sensitisation in the silver bath.
Forget the 3-4 minute rule for sensitising plates. If you over sensitise you increase the changes of fog. This goes for negative and positive images. For negatives there is a theory you need more silver to penetrate into the collodion. Images on collodion happen on the surface of the collodion film, by over sensitising you are just increasing chances of fog and gaining zero benefit. Simply pull the plate up from the silver bath and see if the water beads off of streaks or flows off as a sheet of fluid. When the beading stops its ready..

Fogged shadow detail.
I have found that I push plates too far with development which is bad when in hot weather. I need to stop development before the shadows even start to appear, forget trying to push for the most detail until you get a lot of experience.

Unexpectedly underexposed images.
If an image seems underexposed but you have some confidence the exposure was about right, its possible you spilt too much developer off the plate. When developer pours off the plate it takes a lot of free silver off the plate too. Free silver is the solution that makes your image;s tonality. If it gets washed away it very much looks like gross under exposure.

Pouring developer onto areas where you missed a bit of developer flow isn’t such a great idea.
By pouring directly onto the surface of the plate and not flowing it on from the side, you wash away much free silver from that area and will form a dark patch where the developer hit.

The silver bath becomes contaminated from plate #1 onwards with white commet like dots.
The best practice is to place the plate into the silver bath as soon as the collodion has set. You test this by either putting a fingerprint in the corner or pinching the collodion off from the corner. If the collodion doesn’t run down to fill the area , it has set. Don’t put the plate into the silver bath too soon.

Another cause of epic comet clusters is when you get collodion on the back of the plate. When you slide the plate into the bath, if you catch the back of the plate onto the edge of the bath, you scrape this collodion off the plate. This loose collodion has a tendancy to jump onto the front of the plate as as you drop the plate down further into the bath causing a lot of comets.

I have a third theory for epic comets too, bad collodion. Ive had this happen with New Guy collodion but nowhere on the internet or experts seem to of noticed it. If you put a collodionized plate into the silver bath and instantly see bits floating off, almost like dissolving – Im starting to wonder if the collodion is bad. Collodion can come off glass plates quite easily hence the reason you often need to ‘sub’ glass plates with albumen. But this issue is very different.

Crocadile skin texture seems to be caused by waiting too long to before placing the collodion in the silver bath, there is a very fine line in timing. Also not rocking the plate after pouring off the excess collodion will create a texture of diagnol lines in the image.

Crazy textures form from one side of the plate.
This is essentially oyster marks. As the plate is in the film holder and starts to dry out, it sucks up junk from the plate holder that causes weird contamination marks. But for me its not the plate holder at all, is is the fact I have used an old paper towel to dry the back of the plate before placing it in the plate holder. Always use fresh paper towels to blot of the back of wetplates. The same has also happened with old gloves being worn to handle the plate.

Metallic crystal formations on the top or bottom of a plate.
I am not certain but I think its due to only having just enough silver nitrate in the bath to cover the plate. Add a little more silver nitrate and see if the issue goes away.