Re: aliasing was Re: filmscanners: Review of the Nikon CoolScan 4000

[TonySleep@halftone.co.uk (Tony Sleep)]

On Tue, 10 Apr 2001 09:04:19 -0400  Dave King (kingphoto@mindspring.com) 
wrote:

> The other I'll call
> "shark's tooth", and it looks like tiny spikes at regular intervals on
> high contrast edges.

It's a regular, stepped displacement (on the y axis of a landscape scan) 
of pixels which repeats every 4-5 pixels. It is most visible on high 
contrast edges, but occurs throughout the image. You can see it in the 
full res LS30 scan at my site eg the boundary of her chin against the 
black background. ICE was not used for this scan. As you say, this is not 
related to the normal 'jaggie' phenomenon which arises through aliasing. 
Most, if not all, LS30's seem to do it occasionally or always, with 
Nikonscan. As the scanner ages it tends to worsen. I don't know if v3 
helps, VS certainly does.

-

Regards 

Tony Sleep
http://www.halftone.co.uk - Online portfolio & exhibit; + film scanner 
info & comparisons