The astronomers sometimes cool their cameras to reduce noise for very long exposures. There are cooled cameras for microscopy as well. My main interest at the moment is high resolution stills and videos of protists where I have plenty of light so noise is not really a problem. But I'll be using UV soon and it will become troublesome at once. All I do is change the lenses in these cameras so that the camera lens covers the exit pupil of the photo eyepiece. For the Quickcam Pro 4000 a 12mm Marshall lens is a good choice and is well corrected and coated. But since it's really only working as a transfer lens it's far less important that the eyepiece. I use Leitz Photo Periplan eyepieces and Leica objectives for bright field and Lomo for phase contrast. The Pentax *ist D is used for low magnification photomicrography only because the Webcam 640 x 480 (and 1280 x 960) is more than enough for 20X objectives and above.
D (NPP) Jostein Øksne wrote: > In the amateur astronomy circles, mod'ed webcams are also very > popular. Are their modifications in the same line as yours? > > Jostein > > On 1/2/07, Don Williams <[EMAIL PROTECTED]> wrote: > >> I use a modified web camera for photomicrography. It makes good stills >> and videos at high magnification. The modification involves removing the >> lens mount from the circuit board (exposing the CCD) cutting off a >> millimeter or so to enable a 12mm Marshall lens, that replaces the >> original, to focus to infinity. The CCD gets crap on it very easily. At >> the magnifications I use -- 1200X and more the dust specs are like >> boulders covering detail in the specimens. Cleaning is a very difficult >> job. because taking it all to pieces and putting it back outside a clean >> room is hopeless. I tried working with the camera inside a plastic bag, >> doesn't help much, if at all. Cleaning the *ist D sensor is a piece of >> cake. I use a Zerostat (probably contains Polonium isotopes) to give it >> a preliminary blow and then a Pasteur pipette with a rubber bulb on the >> back to give a final puff or two. So far it has been successful. But the >> Quickcam Pro is a real pain. I'm going to make a small hood -- wire >> frame and plastic sheet to work in before I try again. >> >> D (NPP) >> >> -- >> Dr E D F Williams >> www.kolumbus.fi/mimosa/ >> http://personal.inet.fi/cool/don.williams/ >> 41660 TOIVAKKA – Finland - +358400706616 >> >> >> -- >> PDML Pentax-Discuss Mail List >> PDML@pdml.net >> http://pdml.net/mailman/listinfo/pdml_pdml.net >> >> > > -- Dr E D F Williams www.kolumbus.fi/mimosa/ http://personal.inet.fi/cool/don.williams/ 41660 TOIVAKKA – Finland - +358400706616 -- PDML Pentax-Discuss Mail List PDML@pdml.net http://pdml.net/mailman/listinfo/pdml_pdml.net
