On 24 Jan 2005 at 6:36, William Robb wrote:

Sorry if anyone has seen this post already but I didn't see it back, I'm sure 
I'm missing about 50% of the posts at the moment, so if I haven't replied to a 
post I'm not ignoring you :-)

> I'm not totally conversant with how a film image gets made into 
> seperations for publication, but the centerfolds in the old days were 
> produced from unenlarged Ektachromes, as opposed to enlarging the 
> images, which is what you would do if the image had been shot on a 
> smaller format film.

They would have looked like 70's off-set print, not great and gamut limited. 
Before the advent of computer generated films for plate production plates were 
made on a repro camera using mechanical screens and filters and most often from 
original reflective artwork at 100%. So they would likely have been made from 
prints.

Around the early 80's some of the larger print houses went digital in my neck 
of the woods so until then it wouldn't have been likely that any prints were 
made from direct scans of transparencies. Not until the mid 90's did stochastic 
screening became a reality and off-set prints really started to look fine 
grained. 

Until that point even though most printing plates were produced from laser 
printed films they still used regular screens and were resolution limited 
through the absolute resolution of the imagesetters and the limitations of the 
film to plate process. On top of that few off-set presses had the inherent 
accuracy to ensure sufficient registration to make a high resolution system 
such as Diamond Screen work.

Some reading:

http://www.heidelberg.com/wwwbinaries/bin/files/dotcom/en/products/prinect/scree
ning_technology_eng.pdf


Rob Studdert
HURSTVILLE AUSTRALIA
Tel +61-2-9554-4110
UTC(GMT)  +10 Hours
[EMAIL PROTECTED]
http://members.ozemail.com.au/~distudio/publications/
Pentax user since 1986, PDMLer since 1998

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