Greetings and thanks to all who post:
Ive read the previous posts but since ive been converting 8MM ill contribute my 2 cents.
First, iMovie 5 users download the 5.02 Update, as there have been problems with importing from analog using a digital camera as a passthrough.
Naturally youre going to need an 8MM camera that has audio/viedo output, or you can buy an 8MM cassette deck, there is also a model of sony camera (DCR-TRV240 and some similar makes), that reads both analog (8MM) and digital (Hi8 and D8) which you can use to export through firewire. I use my cassette deck though just so I dont waste the head on my camcorder.
For those who have 8MM cameras without s-video out, use an RCA cable that has all three colours in one cable (red/white/yellow), ill explain below.
For thos who do have S-video, use the S-video cable to export the video and use an Audio only (red/white but no yellow) cable to send the sound out *disclaimer below, keep reading*. Or use the S-video and an audio/video RCA cable (red/white/ and yellow), but dont connect the yellow, just to make sure the video goes through the higher quality s-video cable.
A WARNING however, I recommend using in all circumstances only cables that have all three coulours (both audio channels and and the video) because from experience, I once transferred about 15 hours of 8MM using an RCA audio cable (red/white no yellow) at which point I noticed that I had only imported left channel sound, My camera did not automatically split the sound. The result was that all the way to a burnt dvd, all I had was left channel sound. When I started using a cable that had audio and video, i acheieved full stereo and both channels went through, but I still sent my video through s-video (see above) Take advantage of stereo sound and play it safe.
If you do choose to use an audio only RCA cable, I recommend you take a pair of headphones and listen to your video while its playing on your computer or camera, to make sure you can hear sound in both channels, left and Right. If you only get sound in one, it most likely a limitation with the audio cable, .
If your camera (I know sonys do) has the A/V > D/V OUT option, or anything similar, turn it to ON, this is necessary.
Once you have all connected correctly, turn your digital cam to VCR and start playing from your analog source, this should play on your digital cameras LCD, if it doesnt its A/V > D/V OUT is OFF, this happens on my camera. I start getting vid and audio when I turn it to ON.
Assuming youve already plugged in your FIREWIRE on both ends, and chosen the capture mode in iMOVIE, the video and audio will also come up on your computer. Also, when you use your digital camera as a passthough, make sure to take any digital tape out of it, otherwise, iMOVIE will give preference to the tape inside your camera and take control of the camera and only import the stuff inside the tape in your camera. When you take that tape out and youre not playing anything iMovie will give you a blue screen that says camera not connected or no tape and all the play/stop/import controls/etc will be dimmed, ignore this. Once you start playing from your 8MM source, the vid and audio will override this message and should start to show up in the imovie pane, the only button that will undim is the import button. Now is the time to start importing. Make sure you have the 5.02 update, otherwise the video wont show up and the buttons wont undimm.
Hope this helps all, good luck saving those 8MM memories!