Split tone photography

Jon Harwood is a friend, teacher, photographer and reader of the blast. He came by yesterday while I was trying out some experimental techniques with my computer/printer and sent me this note. Jon has been working in gum bichromate and platinum processes for years and offers up an interesting example of split tone photography.

 Hi Robert,

I hope you had some luck with the split toned print.  The way convention photographers get split tones is usually with two toning baths.  Silenium toner applied heavily and followed with gold toner is a nice method giving red brown shadows and bluish highlights.

With a split toned gum print the shadows are printed with a heavy pigment load and a short exposure while the highlights are printed with light pigment and an extended exposure.

I suspect that any conventional technique can be replicated in the computer--consider the ersatz platinum prints with simulated brushed on borders.

I attached a split tone image that I conjured up with layers, transparency for the top layers.  A blue layer for shadows and a warm tan layer for highlights.  I used the curves control on and adjustment layer to throw the shadow densities up for the shadow layers and the highlight densities up for the highlights.

If you want the step by step process let me know.  This image is subtle, but you can get a more dramatic color effect easily.  This image will print conventionally, no double printing needed.
jh