Far Side: Letting Time Paint Colours
By Bjørn Rørslett

Elm Tree and Waterfall of River in Spate. Multitemporal Technique (Nikon D1, 200 mm f/2 Nikkor)

© Bjørn Rørslett/NN 2000

The idea underlying this image - and many others taken recently - is quite simple. in fact, it is but a logical extension of the multispectral approach, in which bandpass-filtered (R, G, B) images are combined to form a composite colour image. However, here I'm using three separate exposures taken in black-and-white. Later on, the images are imported into the colour channels of a Photoshop image to give the final, false-coloured image. All areas not showing a variation between exposures are rendered with a greyscale identical to the original image, thus showing no colours at all. However, such is not the case for imaged details varying in time and thus these differences in greyscale rendition give rise to "time" colours. You can composite 3 exposures to produce an RGB picture, or 4 takes to give a CMYK image.

Waterfall of River in Spate. Multitemporal Technique (Nikon D1, AFS 28-70 mm f/2.8 Nikkor)

© Bjørn Rørslett/NN 2000

Water Surface. Multitemporal Technique (Nikon D1X, Micro-Nikkor 85 mm f/2.8 PC)

© Bjørn Rørslett/NN 2001