Cyanotype - Digital negative

To produce a digital negative image for our upcoming Cyanotype event, I have picked a colour picture which I shot in Blackpool last summer.

First I opened is photoshop and duplicated the layer.

We need a contrasty black and white image so I turned the photograph into black and white by using the gradient map. The reason why we used this option is to keep the RGB and don't distort the colours by using the black and white option.

Then I changed the levels to make the image more saturated.

So now I have a contrasty black and white image, for printing it to a transparency film. But first I still have to adjust a few things.

To sharpen the image I used the High Pass option from the Filter -> Other menu. By using this we can lose detail so be careful with this filter.

I have changed the screen mode to overlay. So the background copy and the high pass filter now overlay.

I have to flatten the image than paint it blue with the paint bucket tool. Hot key "G". But first mix the colour for the cyanotype blue. We can do it via our colour panel. Double click on it and add Red 47 Green 161 and Blue 219.

 And use the screen mode and set it to overlay again. So the coloured image will look like this.