using 2 DV camcorders as webcams

[andy308]

I have 2 sony DV camcorders.

They are both plugged into my iMac 24 inch using the 2 Firewire ports. On the Mac, one port is 800Mb/sec, the other is 400Mb/sec

Both cams show up in the webcam list in Cam Twist as DV cam 1 and DV cam 2, but I can't seem to switch between the 2 cams.

Only one works.

Any ideas of how I can get both cams to work so I can switch between them?

Do I need a firewire hub? Do I need to use the same type of firewire cable connectors?

thnx

[SteveG]

I've seen this problem before. Some part of MacOS X has a problem with identical cameras on the same bus. Getting a hub won't help.

[andy308]

Thanks, but just found out that the cam connected to the firewire 800 port won't give an image in any of my programs.

I don't think the camcorder is compatible with firewire 800. Its quite an old camcorder.

[Bencredible]

In OS X you can only have 1 DV camcorder hooked up per bus. In most Macs the FW400 and FW800 ports are shared and are on one bus, which means only 1 DV device can be hooked up at a time, even though you may have 2 to 4 firewire ports on your computer.

The solution is to get a Firewire card and utilize that. Some cards have more than 1 bus on board which means you could get 3 or 4 DV devices working. All depends on the card.

If you have a MacPro you can also grab a BlackMagic Intensity Pro and bring your camera in via HDMI. That will give you the highest quality, but it will also be the hardest to configure.

[adamfenn28]

While I have not been able to get multiple identical DV cameras to work on the same built in bus, I have gotten two identical cameras (Canopus ADVC-110 AD Converters) to work on a FW ExpressCard/32 card with only one bus. I've never gotten three to work. I've also had no problem getting multiple non-identical cameras to work, even on the integrated bus.

[Bencredible]

I am very surprised that worked at all. Technically speaking Apple only supports one DV camera/DV device, regardless of how
many FW Controllers you have, although I have found in newer versions of Mac OS X it seems to deal better with DV sources so long as they are on a unique bus. However, Apple does not support that, their mantra is one DV device per computer, period. DV devices normally listen and broadcast on ISOCH channel 63, which means no matter how many busses you have, there will always be conflict if they are all trying to access the same channel. This could be what you're running in to, two identical cameras colliding on the same ISOCH channel.