Hi Tony,

I promised that I would write up some of my exploits with the video capture card - so here are a few notes.

I went to the amateur radio show at Donnington Park, not dreaming of finding video gear but I came home with camera, £199, and video card for the PC, £69. Ouch!

The camera is a JVC TK-C621. It has a 1/3" colour CCD of 753 x 582 (440,000) pixels and produces an output with 470 TV lines. It is mains powered, though there's a similar model with 12 V dc input. It came with a simple 16mm lens and C to CS-mount adapter ring.

I quickly connected the camera, minus lens, to the 0.4 x C-mount adapter on my stereo microscope and showed the picture on a TV via its SCART connector. Happy that the camera worked I tackled the next step, which was to install the "MovieStar" video capture card.
Mechanically that was easy as there was a spare PCI slot in my PC, which is a 300 MHz Pentium II with 64 M byte RAM and plenty of hard disk space. The camera connected via co-ax to a phono socket on the MovieStar card. (The card can actually support 4 video inputs if one uses the multi-way socket and there a Video-S socket as well.)

The software was more of a problem. The original CD-ROM appeared blank to my computer but was quickly replaced by the suppliers.
After telling the installation program where the drivers were (not on drive D: as it expected) it installed OK and I was able to run the video editing program supplied, Video Wave, and having selected video source 3 I could see a small black and white picture. OK, select video source PAL and up comes a colour picture. Setting the appropriate options enabled the video to be monitored in a frame size of 384 x 288 pixels. So far, so good. The problem came when I switched on the PC next day and tried to use the video capture software. When I selected video the PC crashed and re-booted itself. Worse, for some reason I had to "remove" the video drivers
and re-install them. I now believe that this trouble was caused by unsuccessful sharing of the IRQ that Windows allocated to both the video card and an Ethernet networking card. Since I "removed" (in software only) the networking card, the MovieStar card and software have worked fine, so watch out for shared IRQs! Plug-n-play it may be but it ain't perfect!

Capturing short video clips and stills was easy but care needs to be taken to select the required format and any compression required. Big hard disks are needed if significant duration of video clips are to be captured: 126 M byte per minute at best quality, down to 1 M byte per minute for lowest quality. Stills may be captured as 768 x 576 pixels by 24bit colour, meaning each frame takes 1.3 M byte.

Results on the stereo microscope have been quite pleasing, though it requires considerable patience to catch the best view of moving
pond-life. Watching the screen rather than looking down an eye-piece is more relaxing, though the picture definition is not nearly so good, of course.

I have also found that I can hold the video camera, again minus lens, over the tube of my Prior compound microscope with eye-piece and top tube removed. This allows the camera to balance quite steadily on the 1.75" main tube. So far this has been a hand-held activity but it has convinced me that a clamp-on C-mount adapter for the Prior could be good! Illumination by LED, of course, thanks to
Tony Dutton!

OK, so what pictures did I get? I have attached a couple to this
mail and some more to the following mail. All except the fly wing
hairs were taken with the stereo.

(Ed - and I think, the section of lime wood. I have also included a picture of foraminiferous sand which John has taken with his Kodak 120 digital camera coupled to the stereo - this has come out very well, with little trace of the vignetting I get with my Fuji DX7. The 'insect' is a mayfly(?) nymph. Congratulations to John on some impressive images! I know John is knowledgable on computers and electronics amongst other things, but he is the first to admit to being a beginner at microscopy. So let's hear from all you other beginners out there!)

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