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…

Lea Formula 3 – Portrait Collodion Results

Over the past 7 months I have been testing several different collodion formulas.  This is the first set.

This is Lea Formula 3 – Portrait collodion, from “Manual of Photography” by M. Carey Lea

It is a slow ripening Cadmium based formula.

At one day it is unusable.

At 2 months it’s almost usable.

At 5 months it’s nice.

At 7 months it’s nice and maybe a bit faster.

The advantage of this formula is that once ripened it’s extremely stable.  It is said to last for 12 to 18 months or more.

Disadvantage – It’s cadmium based and it takes 5 months to ripen.

I have made a lithium based version of this formula that hopefully will ripen slightly faster and last as long.

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At 7 months you can see that Lea Formula 3 is still a nice yellow color. A hybrid using LiBr in place of CdBr2 is aging faster.