A few newbie questions

PiezoDN Digital Negatives
1

Hello,

I have successfully linearised a curve for cyanotype. The prints look good and I am really impressed with the system. I am using a simple 50W LED UV light about 12 inches above the printing frame for an 8x10 print. Sorry if these questions are basic but I am completely new to this.

First question is if I want to print bigger I will have to raise the lamp a little. If I recalculate the print time for maximum density will I have to redo the calibration all over again or will the curve I have produced still work?

Second if I print on a different paper I assume I will have to start over.

Third question: I have used the master quad to print the limit file for Argyrotype, but only the first 3 rows show any density. Is this not good enough to start the linearisation procedure? Perhaps I should use the cyanotype master to start limiting instead?

Fourth is about the ICC profile. The manual seems to imply that this is mainly for platinum/palladium printing and increases contrast. Can it not also benefit other processes like cyanotype?

Thanks for all your help so far.

Best,

Mark

2

Hi Mark,

  1. Raising the light technically reduces irradiation and should not require re-linearization - BUT only if you could perfectly match the amount of irradiation at the lower height. Because there may not be a way for you to conveniently do that it would be a good practice to create a linearization at the new height after establishing your correct exposure time (the step exposure that first makes dMax).

  2. Usually a paper imparts quite a bit into a linearization. It absorbs chemistry and humidity differently, and it may impart its own peculiarities into the process. So we do recommend a linearization when anything changes in a darkroom workflow whether that is paper, chemistry, relative humidity (especially with platinum but to some extent humidity affects some cyanotype formulations).

  3. Had you already established (through unprinted Pictorio UltraPremium OHP film) the standard exposure time (the step exposure that first produces a dMax?) If not - this is critically important. If so you can try another curve such as the platinum starting curves. Also you should use the 21x16 target with any alternative process that involves coating of the paper. Use it from the first linearization, through to the second, and confirmation if you make a 3rd run for precision.

  4. The ICC profile is only for OS X using PrintTool. It allows the use of Contrast Matching to uncalibrated displays. Print Tool managed with the ICC will darken the shadows. To view a purely linear Piezography print you need a hardware calibrated display - otherwise you can not see the shadow detail. Also the new Apple displays have contrast ratios of 500,000:1 and 1,000,000:1 which can not be calibrated to print. So contrast matching can be very useful if you are without an Eizo or BenQ with hardware calibration (they are all low contrast displays.)

Best,

Jon

1 Like
3

Dear Jon,

Thank you that is really helpful

On q3 I did work out the ‘maximum black’ through the pictorico film before printing the limit target so I will try using a different starting curve.

Best,

Mark