Since I know people find my web pages while searching for information about Nikon scanners and Mac OS X, I’d like to offer the following endorsement:
The Ratoc FR1SX Ultra-SCSI to Firewire adaptor works perfectly with Mac OS X 10.3, and doesn’t need any drivers.
Plug the unit in to the back of your SCSI-based Nikon film scanner, and you suddenly have a Firewire-based Nikon film scanner. This can then be used with Ed Hamrick’s excellent VueScan software to fulfil all your scanning needs.
No adaptor drivers, no Nikon drivers, no Nikon software of any kind—so this solution should work fine with 10.4 / Tiger and other forthcoming OS X versions too.
Unlike USB options, the Firewire interface seems to result in scanning being just as fast and reliable as it was with SCSI.