For a given UV unit, will Cyanotype be faster or shorter than Pt/Pd?

[MatthewDunn]

I just received my chemistry and am about to attempt a minimum time to "black" test. On my UV unit, Pt/Pd is about 4 minutes. Just wondering whether to start around that time, much shorter, or much longer, for instance.

Thanks in advance,
Matthew

 

[revdoc]

Classic cyanotype is quite a lot slower than the other ferric processes I've used. Kallitype tends to be about 30 seconds, VDB about 5 minutes and cyanotype 22 to 32 minutes. Shorter exposures work, but with less Dmax.

It's a print-out process, and I find the trick with cyanotype is to expose until your "black" goes grey. It takes a lot more exposure than you might expect.

 

[nmp]

Classic cyanotype is quite a lot slower than the other ferric processes I've used. Kallitype tends to be about 30 seconds, VDB about 5 minutes and cyanotype 22 to 32 minutes. Shorter exposures work, but with less Dmax.

It's a print-out process, and I find the trick with cyanotype is to expose until your "black" goes grey. It takes a lot more exposure than you might expect.

Potassium ferricyanide is a strong absorber of UV light which brings down the overall efficiency of the exposure.

:Niranjan.

 

[MatthewDunn]

Ok. Thanks @revdoc and @nmp. I will post back with the results of my experiments. Thanks for your assistance.