(re-)calibration: digital camera, part 1
Integrating sphere at the Laboratorium voor Lichttechnologie, KAHO Sint-Lieven, Gent, BE
Thanks to Richard Vanraes from KAHO, I was able to measure the distortion of my digital camera in a lab. We used the integrating sphere to get measurements of the response of the entire system CCD sensor-lens with full zoom and fixed 1:5.6 aperture.
I double checked one picture of inside the sphere with a picture made of several pictures, each fragment measuring a part of the CCD response to the light coming from the window of the integrating sphere, that was illuminated with an halogen lamp. We had to wait until the couple lamp-sphere becomes stable: the temperature of the lamp was warming up the sphere and the amount of light passing by the window was slowly growing… for approx. 30 min
Now I have to figure out how to use this to correct my measurements… but that’s a good start :)
multi-samples CCD response measurement
picture of the vignetting at max zoom & 1:5.6 aperture
The vignetting in the 1st horizontal line of the picture (in blue the raw data and in red after a gaussian blur)