too much contrast in NEW cyanotype---- Help

Dear Friends

 

I've been printing in NEW cyanotype process for past four days

during which I tried different films and different developers

including PYRO yet still I get too much contrast in my prints. Would

anyone know what to do ????? I read that adding a citric acid my

help but I don't know the proportions. What could be other reason

for too much contrast. Every answer will help. Thank You in advance.

Dominik T Wyka

Cyanotype is a relatively high contrast process; it will help to print from a much flatter negative than you're probably used to. Try making some shots at half your usual EI and develop with a one stop pull (reduce development about 20% from your usual time) and see if that helps; if necessary, you can increase exposure and reduce development still further.

 

The other thing you can try with your existing negatives is less exposure of the cyanotype itself -- try cutting back to half your current exposure and see what you get. That should help cut down the contrast, since cyanotype increases contrast at increased exposure (shadows get darker, but highlights change little).

I expose my negatives 1/3 less than the recomended EI and develop them 50% more than the standard development time, and get good results with the old cyanotype recipy.

But as you know It depends on the shot, the subject and the desired effect.

As I dont have a densitometer, I can´t give you exact density ranges.

A good negative for cyanotype should print correctly in a gade 0 paper (but, that depends on the enlarger, the paper, etc).

Tell us how do you expose your negatives, and what formula do you use.

The best and easiest road to good negatives for cyanotypes and other processes is the digital way. Adjusting the contrast curve for differnt processes with the same image.

Hi Dominik,

this is (besides the fact, not all pictures suitable for cyano are shot on appropriate neg format) the main reason, I do interpos-/negatives.

Typically printing at optimum contrast (rather to the soft side) positive on variocontrast paper and copying on i.e. reprofilm (contrast-transformation to be controlled by development).

In contrast to postings before I rather prefer negs rather hard compared to printing paper, to get the whole range from deep blue to white (matter of taste?).

BTW, the citric acid recommendation is 4% i.e. 10 g for 250ml Water. Use as first bath for 1-2 Minutes then wash with pure water(appr. 5mins). Be careful not to wash in excess. Cyanos tend to fade a good amount in highlight areas if overwashed.

Martin

Ware recommand to dilute by half to get less contrasty image.

But it is better to get less contrasty negative.

Ware cyanotype appreciate quite normal neg Just a little over develop. You a classic developper and add 20% time .

 

CHristian Nze

Are you adding any Potassium Dichromate, 1% to the mix of A and B?

 

And I always thought that washing the print in dilute Citric acid (or even Acetic acid) intensifies the density..

I read again the article of Ware and find this:

 

"The contrast of the sensitizer can be lessened by adding citric acid, so that it can even accommodate a negative density range of 2.6 or so. Conversely,the contrast can be increased by the addition of more ammonium dichromate solution."

 

hope this help

If you have the hardware/software you might try making a digital internegative for Cyanotype printing - then it is much easier to change the negative's contrast.