> If others are willing to join, I would like to make this an open > source project. As said, my biggest problem currently is getting a > good 45/0 probe. I am not an expert in all fields and thus help is > welcomed (straylight-, wavelength-, bandpass-correction,...). I > thought about using the optics of existing devices like Graeme > mentioned, but I basicly want others to rebuild the device quickly > without being an optics expert. So it should be plug-and-play. I am > currently thinking about hiring an optics company making a small > batch of probes, but I really would like to avoid it. Wolf, I would strongly advise that you get in touch with Danny Pascale at www.babelcolor.com Danny has expertise in building optical systems of all sorts. Tell him I sent you ;-) MfG, Roger Breton | Laval, Canada | graxx@xxxxxxxxxxxx http://pages.infinit.net/graxx