Cadmium Free Collodion – Aging Study – Part I

Five weeks ago I began an aging study on four cadmium free collodion formulas to see how fast they age.  I have data for some of the formulas at various times, but I wanted to do a more controlled experiment at more frequent intervals so that I could see at what point a particular collodion slowed.

The four formulas:

  • Lithium Chloride modified
  • Ammonium Chloride modified
  • UVP #1 (Ammonium Iodide, Lithium Bromide)
  • UVP #3 (Lithium Iodide, Lithium Bromide)

I was going to wait until I finished the study before posting anything, but one of the formulas surprised me.  I was expecting the UVP #1 to behave like it’s cadmium containing brother, remain fast for a short while, and then slow after a few weeks.  It didn’t.  It started out at what I consider to be a normal speed, and then at 2 weeks it got noticeably faster. I was using the same silver, dev, fix, temp, etc., and the speed increase wasn’t consistent across all the formulas being tested, so I don’t think it was a flaw in my setup.  I have seen the UVP #3 speed-up slightly over time, but never really paid enough attention to the UVP #1 to notice a change.  I typically have a new batch of something to shoot, so I never saw this in my own shooting.

At Five Weeks
Five Weeks

My procedure is to shoot to get a correctly exposed plate using a stopwatch, and then the following week I start at that exposure, and adjust if needed.  Since I can’t get every plate 100% exact, I grade +/- vs the others in the set to determine fractions of a second.  I don’t think any plate is more than ½ second exposure away from where it should be, so I think it’s an appropriate way to adjust for fractions of a second.

Grading Plates
Grading Plates

At 5 weeks all of the formulas are as fast as or faster than when mixed.  Also, I like the look of the plates at two-three weeks better than the one day or one week plates.  It’s subtle, but there is a quality difference.   The two chloride formulas are consistent and seem to be fairly stable.  I plan to do a separate write-up on these formulas once I understand them a bit better.  I think they may have some advantages in contrast and crispness (I can’t think of a better way to describe what I see).

Collodion color at 5 weeks

The collodion is not being stored in a refrigerator, but it is being kept in a cool dark-ish location.

I plan to continue until all the formulas slow.  In the meantime I’m going to start another aging study using some of the most popular formulas being used today.  Old Work Horse, Old Reliable, QQC, and UVP #1 as my control.  It should be interesting!


Lea Formula 3 Ripened 18 months vs. 3 months

Just a quick test to show that Lea Formula 3 that was made 18 months ago performs the same as Lea Formula 3 made three months ago.  The 18 month old collodion was not stored in a cool dark place, but left on a shelf in my garage.  So I consider it to be real world aged.

As usual, the plates were run using the same silver bath, developer, fixer, and exposure.  They are quite close.  In person I really can’t tell the difference between the two plates.

UVP4 Lea3-5







Lea Formula 3 is perfect for people who don’t shoot a lot, or want a consistent collodion that doesn’t go bad.   I’ll continue to test this collodion to see how long it continues to produce good plates.  More than two years?  I think it’s very possible




This is what 18 month old Lea Formula 3 looks like!


Cadmium Free vs Lea Formula #1

It’s been a while, so I figured that I should post something.

A lot of my focus has been on Cadmium free Collodion’s, so I wanted to show, as best I can, the difference (or same-ness) of a couple of different formulas.  I’ve done many multiple plates using these formulas, so I’ve tried to choose representative samples of each.  They are all from my standard shot, using the same silver bath, developer, fixer and varnish.  The only variation is exposure time for the UVP #3 All Lithium formula.


Collodions shown:

Lea Formula #1 – this is a classic Ammonium Iodide, Cadmium Bromide Formula that is similar to Quinn’s Quick Clear.
UVP Formula #1 – this is an Ammonium Iodide, Lithium Bromide Formula that behaves similarly to the Lea#1
UVP Formula #3 – this is a Lithium Iodide, Lithium Bromide Formula that is 1 or more stops faster that the other two standard speed formulas.

The Lea 1 and UVP 1 were both exposed for 7 seconds while the UVP 3 was between 2 and 3 seconds.

They are all very close, but I prefer the UVP #1.  The UVP #3 has less detail in the blacks, so opting for speed seems to give you a little less tonal range.  I’m going to play with this formula to see if I can improve it while maintaining the speed.

Other things I am working on:

  • Different developer formulas that I will share at some point.
  • A new Cadmium Free Collodion that is faster than the UVP #1, but slower that the UVP #3.  It seems to give great tone and contrast.  The only drawback I see right now is that it is harder to visually develop.  I might be looking for a few people to beta test it for me.  Let me know if you might be interested.

More Cadmium Free Collodion Work- Extended Life

I have been doing more work with the all lithium formula.  This time I made a batch and split it into three samples so I can try and extend the life of  this rapid ripening collodion.

Sample 1 –  All Li (Control 1)

Sample 2 – + acetone

Sample 3 – add acetone after 10 days of ripening

Sample 4 – All Lithium formula aged 2 months

Sample 5 – Lea formula 3 Aged 5 months. (Control 2)

This Kodak patent explains how adding acetone to a salted collodion mixture will halt the aging  of the collodion.

The idea is to see if I can extend the life of the mixed all lithium formula beyond 1 month.

After aging the samples for 24 hours I made some plates.

Samples 1,2 & 3 all behaved the same – as expected.  At one day the all lithium formula is faster than the cadmium version, but not as fast as the lithium formula ripened a week to 10 days.

All Lithium                                     Sample 1 (2 and 3 seconds)


All Lithium –                  2 months old (6 seconds)    Sample 2 (3 seconds)



Sample 5 Lea Formula 3 (7 seconds)


It looks like at 2 months old the all lithium formula is now as slow as a the cadmium formula.

After 10 days of aging, I retested Samples 1, 2, & 3

At 10 days all were faster.  Here are samples 1 & 2 (2 seconds)


Sample 3 with acetone added  (2 seconds)


All 3 plates were basically all the same.  Easily faster than at 1 day of ripening.

The collodion Samples 1 & 3 both ripened and turned more straw color, but sample 2 stayed the same pale yellow.  The interesting bit is that sample 2 was just as fast as samples 1 & 3.

Samples 1, 2 & 3 after 10 days

photo At 10 days I added acetone to sample 3.  It will be interesting to see how these all age and ripen.  Hopefully stability can be increased while maintaining speed.

I also added Acetone to the 2 month old all lithium formula.  This has been mentioned in the period literature as a way of extending the life of collodion that has gone off.  So far I have not seen a change.  The collodion is still dark & red.

More to come!



Cadmium Free Collodion – Lithium Bromide / Lithium Iodide Collodion

Initial Results.

I mixed up some collodion using lithium bromide and lithium iodide.  Both salts are soluble in ether/ethanol, so it was a pretty straight forward process.  I added both salts to the ether and ethanol, mixed until dissolved, then added the collodion USP.  It was a pale yellow color, similar to the cadmium version.  Since there is no Potassium in the formula, there is no potassium bromide precipitate to worry about.  I aged it for one day then shot a plate.

Ripened 1 day

At one day it already behaves different than the cadmium version.  Using my standard setup and exposure time, I was able to get an image, but it was flat and foggy.  The same shot with the cadmium version I was just getting a white plate at various exposures.  Unfortunately I didn’t vary my exposure times to see if a shorter time would have given a decent plate. I was testing a series of formulas, and I just thought it need more ripening.


Ripened 9 days

My first plate again was flat and foggy, but better than the first shot at one day.  This time I varied the time to see if I could get a plate with good tone, contrast and no fog.  Well, I did!  My typical exposure time using my standard shot is 6 to 8 seconds, maybe down to 5 for some formulas.  Well, the all lithium formula gave me an exposure time of 2 seconds.  Nice contrast and tones with no fog.  This might come in handy when doing in-studio portraits.  It may actually be too fast for some conditions using a fast lens.

Now I need to see how long this formula stays fast.  Will it degrade quickly?

To be continued…


The intent of this blog is to test various chemicals and techniques used in the wet plate collodion process.  Reality is that everything has already been done back in the late 1800’s, so most everyone today is just reinventing the wheel.   That said, we can duplicate what has been done to confirm and document the outcome.  My current interest is in the collodion formulas from M. Lea Carry.  I am currently testing several of his formulas, along with some cadmium free formulas, and will post the results once I have a a few more sets of plates finished.  To try and make the testing as consistent as possible I developed a standard shot that can be duplicated plate after plate.  It uses CFL’s as a light source, which give a consistent light source, but I will have to develop something outside to test natural light.  Controlling the sun will be a bigger challenge!

Standard Shot Rig
Standard test shot rig.

This is the rig I came up with for the standard shot.  It uses my Speed Graphic with 5″ Gem Petzval.  This photo is still in the development stage.  I added an extra light at the top and various subjects including a grayscale and a color scale.  Using a stopwatch I have been able to get consistent plates from this set up.  I have already seen some interesting differences between the formulas, and am excited to see a couple as they age.

First set of test plates.
First set of test plate.

Other things I would like to study are fixers – KCN vs Rapid Fix and Hypo.  The thought is that KCN gives a warmer image, but developer & development time may have a greater influence.

More to come…