“Orton imagery” as it was once termed in Photo Life magazine is a technique that famously originated in the work of professional photographer Michael Orton. He created the effect in the 1980s using a relatively straightforward process in order to imitate the look of watercolour paintings. Specifically, he was inspired by watercolours which have had details emphasised through the use of an ink pen.
The basic concept of the Orton effect is to use different versions of the exact same image and layer them over each other. One of the layers needs to be sharply in focus and overexposed, which originally would all be done manually on a professional SLR camera. This is the detailed element of the finished image and can be equated to the pen-drawn lines in the paintings that inspired Orton. The other layer would also be overexposed, but this time completely out of focus. This layer’s purpose is to add the depth of colour to the image in the same way the paint would in the watercolour example.