Digital BW, The Print

> -----Original Message-----
> From: DigitalBlackandWhiteThePrint@yahoogroups.com
> [mailto:DigitalBlackandWhiteThePrint@yahoogroups.com] On Behalf Of
> hogarth@...
> Sent: Friday, July 01, 2005 3:16 AM
> To: DigitalBlackandWhiteThePrint@yahoogroups.com
> Subject: Re: [Digital BW] scanners for 8x10
> 
> Scott McLoughlin wrote:
> 
> > Stupid question, but why *are* drum scanners so much more expensive
> > than the alternatives?
> >
> > Scott
> 
> They are harder to make.

You fail to point out that the Professional high end drum scanner gave
better resolution the larger the final image produced, because the input
sampling rate increased with enlargement.

It was perfectly possible to produce a 30x enlargement, which amounts to a
35mm outputting to 45" along the longest side.

In addition the colour correction and tone reproduction were
pre-programmable to suit any given proofing requirement.

The editing facilities were extensive and to such a degree that final output
- screened halftone - was generally proof ready and required no additional
modification.

These edits included catchlight drop out, yet to be seen on any flat bed I
have come across, both UCR and GCR with GCR having a dropout limit set for
non image printing areas

USM was done on the fly

Originals up to 24"X20" could be handled (reflection and transparant)

You could batch scan so that in their heyday these were extremely profitable
devices.

In addition they later were used as input devices to supply images for 
electronic page makeup workstations.

Eventually 3rd party organisation started to produce relatively cheap
interfaces that allowed the scanner to output to a Mac/Pc workstation.

The same organisations even introduced the capability to process made-up
pages back into the scanners output drum, which could go up to 40"x30", thus
enabling an 8 page to view capability including both images and text.

On the other hand the desktop scanners all rely on the use of a separate
workstation for post scanning modification, meaning that their productive
output was considerably lower than the high end drum scanner.

Most of them were capable of inputing images to a workstation only and they
had serious original input size limitations. 

Final output was often through an imagesetter which did allow the production
of combined image and text pages

They were very popular during the early growth stages of the desk top
publishing revolution

It is these machines that seem to appeal to the Photographer seeking to
digitise his/her images because they are pretty cheap to buy and apparantly
readily servicable
 
Richard


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