In a message dated 1/10/2001 2:22:06 PM EST, [EMAIL PROTECTED] writes:
> - Are the visible jaggies always directly related to the irregular
> interrupted scanning process?
No, these aren't related. The jaggies appear to be related to
some kind of resonance frequency, and only happens when
the scan speed is steady and the scsi transfers are larger than
one scan line. Adding a scsi wait between one-line scsi transfers
seems to solve the problem.
> - Ed, do you know if Silverfast uses the same SCSI-command as Nikonscan
> (using 64K blocks and not complete scan-lines)?
I haven't actually traced the scsi commands that SilverFast uses.
I suspect SilverFast isn't using two threads to do the scsi I/O. If
you use one thread, you get delays from Windows when you
write out a block of data and Windows decides it needs to flush
some memory to disk to free up some space. When I switched
to two threads to do scsi I/O more than a year ago this stop/start
problem got significantly reduced in VueScan.
Regards,
Ed Hamrick