CR: effect of viewfinder-cover in IR-photography

(für die deutschen Leser: Es folgt ein Diskussionsbeitrag für das CR-Forum, der illustriert, warum man den Sucher gegen Lichteinfall während der Aufnahme abdecken sollte, wenn man IR-Fotografie betreibt)

i did not manage to include my images in the canon-rumors-forum, so here are the samples of how light through the viefinder can affect IR-photography:


1: a typical sample: the blue light in the right upper corner and in the middle right area is caused by light from the viewfinder:

2. To test the effect, i chose an extreme setup: direct sunlight in the late afternoon, perfect angle for getting the maximum amount of light into the viewfinder. The blue cast is all over the pic.

3. Now the same setup, with the viewfinder-cover from the camera-strap attached to the viewfinder: No blue light at all:

tec specs(2nd image):

5d MKII, IR720 Filter, 32s, f13, ISO 500