Derivative is where an image has been abstracted to a form that doesn’t readily resemble what would normally be considered a photograph. Sometimes it is to make the image look like a painting whether it be pen and ink, pastel, oil or watercolour. Sometimes it is deliberate use of photographic technique to create a more surreal image – something we wouldn’t normally see with the naked eye. I could have called these ‘creative’ but a creative image can still be recognisably a photograph and so ‘derivative’ is perhaps a better description.
Also included here are some infra-red (IR) images. Our eyes don’t see IR so it fits the category well. Monochrome IR could resemble a photograph but the spectral response is such that tones don’t match the colours we expect to see – a blue sky is usually almost black and vegetation is almost white. Some IR images here are left in colour – the limited colour palette and perhaps a little post-processing of the image can result in some quite artistic interpretations though maybe not to everybody’s taste.