Thursday, August 27, 2009

Nikon D80 / D200 spectral response UV IR

This time a technically oriented entry, about the spectral sensitivity of a (modified) Nikon D80 camera. This camera uses actually the same 10Mp CCD sensor chip as the Nikon D200, so the results should be transferrable to the D200 also. The camera has been modified by removing the internal filter, so the response is that of the bare sensor. This is a result of the work and has been made available through Dr Geert Verhoeven, Uni Ghent who works on aerial UV + IR archaelogy and with whom I have the pleasure to co-operate on this subject. I'm greatful for his permission to publish this result here.

[click on image to see a larger one]

Spectral response (valid for about 380-850nm) - (c) Dr G Verhoeven:

[Please note that the valid range of the results is about 380-850nm only, since outside that range, the equipment used was not suitable and the measurement errors too high.]

It gets quite obvious, that this camera has some useful UV response in the red channel and only minimal response in the green and blue channels.

For near IR (NIR) however it shows quite high response in the red but also green (>750nm) and blue (>780nm) channels.

[this is a excerpt from:

Journal of Archaeological Science Ref: JASC08-363R1
Title: An Attempt to Push Back Frontiers - Digital Near-UltraViolet Aerial Archaeology
Authors: Geert Julien Joanna Verhoeven, Ph.D.; Klaus D Schmitt, Dr.-Ing.


Stay tuned, more will follow on that fascinating subject...

More info on this very interesting field may be found on my site