Image from Unibrain Fire-i camera is jerky due to slow frame rate.

[jcrooke]

I have two Unibrain firewire cameras attached to a laptop (DELL Latitude D510). In MAX, one camera looks fine (the frame rate indicator reads 15/15) but the other flickers and jerks (frame rate indicator reads a variable amount from 8/8 to 11/11).

When I try both cameras in the same configuration on another laptop (DELL Inspiron 8500) they both look fine. The settings in MAX are the same in each.

If I just connect the jerky camera... 1) to the jerky laptop, it behaves jerky 2) to the steady laptop, it behaves steady.

If I just connect the steady camera... 1) to the jerky laptop, it behaves steady 2) to the steady laptop, it behaves steady.

It seems that something is corrupt in the IMAQ IEEE1394 configuration for this camera. How do I recover?

[David S.]

Hi jcrooke -

It's unlikely that the NI-IMAQ for IEEE 1394 Cameras driver is at fault in this situation, because one of the cameras always works on the "jerky" laptop.  A more likely cause of behavior like this--where a camera suffers bad throughput on any computer--is the firmware.  The camera may need a firmware update or refresh.  You might want to contact Unibrain to check the firmware of your cameras.

There is also a distant possibility that the power drain of this camera is to blame.  Laptops are hard-pressed to supply power to 6-pin FireWire devices, and one of the cameras may be drawing too much power.  As I said, this is unlikely because both cameras are the same model, but you may want to plug them in to their own power supplies to be sure.