AM, FM, and new alternatives: The Revolution and Evolution of - - PowerPoint PPT Presentation

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Sep 18, 2023 268 likes •458 views

AM, FM, and new alternatives: The Revolution and Evolution of Screening Steve Musselman Sr. Manager, WW Business Development Agfa Corporation Screening dates back to the origins of photography 1852 William Henry Fox Talbot patents

SLIDE 1

AM, FM, and new alternatives:

The Revolution and Evolution of Screening

Steve Musselman

Sr. Manager, WW Business Development

Agfa Corporation

SLIDE 2

Screening dates back to the origins of photography

1852

William Henry Fox Talbot

patents photo-etching uses a woven cloth

screen to modulate tones of photographs.

1881

Frederick Ives

1882

Georg Meisenbach

1890

Max and Louis Levy

1890s Max Perlmutter

Early FM Screening?

SLIDE 3

100 years later…the FM Revolution

1993:

The advent of Frequency Modulation.

Agfa’s CristalRaster
1994 GATF InterTech award
Linotype-Hell’s

Diamond screening

SLIDE 4

And, the Computer-to-Plate Revolution

1990: Advent of the “digital plate”.

N90 photopolymer plate; variant of “projection plates”

1994: Advent of Computer-to-Plate.

Optronics, Gerber & Creo CTP

products 1st to market

Now, in 2003,

there are over 16,000 CTP systems installed world-wide.

SLIDE 5

With CTP, AM screening has reached its limit.

Amplitude Modulation: Highlight and shadow detail

can often be lost on press.

Frequency can now exceed

engine addressability.

SLIDE 6

CTP quality can exceed press capabilities.

A CTP plate can resolve more than the press can hold.

10.6µ line

Top: Kodak Thermal

(Imaged on Creo)

Middle: Agfa Silver (violet)

(Imaged on Galileo)

Bottom: Agfa Thermal

(Imaged on X45)

Printed Sheet Plate

SLIDE 7

FM: fine, consistent dots; “grainy” midtones.

FM implies fixed size, controlled

placement to generate tones.

Clustering often occurs

in the mid-tones

Some 2nd order FM create

swirls to minimize grain

Clustering

SLIDE 8

1st and 2nd order FM screening examples

Press-sheets: Plates:

2nd: Luscher 1st: Agfa 2nd: Creo

SLIDE 9

Trade-offs: AM versus FM screening

Each technology has its best fit. 175 lpi AM vs. 21 micronFM

AM FM Rendering of fine details

Smooth flat tones +

Less Inherent Dot gain (TVI)

+

Press reponsiveness

(ability to adjust colours)

+

Reduced Color Moiré
+

Reduced Subject Moiré

HiFi colour separations

Extended Run length +

Reduced clipping in highlights
+

Rendering of midtones +

Open shadow details
+

SLIDE 10

Hybrid screening – trying to bridge AM & FM

Segmentation method

Specific AM & FM areas “Classic” Hybrid from

Artwork Systems (PCC)

Stochastic distribution

f AM dots

“Spekta” from Screen

SLIDE 11

XM: an alternative to AM, FM & Hybrid

Implemented via a

single tiling algorithm

Patents awarded to Agfa:

1997 EU, 1998 US

Marketed by Agfa as :Sublima Similar approach by Artwork Systems (Quantum) Similar approaches by Esko-Graphics and Creo

(SambaFlex & MaxTone for Flexo)

XM = Cross Modulation

A screen that crosses

smoothly from AM to FM

SLIDE 12

Not stochastic: FM dots at AM angles

Stochastic implies random
Highlight details may look

stochastic, but are not.

FM placement along existing

AM angles of mid-tones.

XM’s AM-to-FM transition point

is line frequency dependent.

SLIDE 13

FM, XM & Hybrid screens side-by-side. (200x)

Agfa CristalRaster 21µ 1st order Heidelberg Satin 20µ 1st (?) order Creo Staccato 21µ 2nd order Agfa Sublima 340 lpi XM screening Fuji 300 lpi CoRes AM Dithered Grey Screen Spekta Random AM 21µ

SLIDE 14

FM = increased gamut?

300 lpi AM

FM attributes are really

small-dot attributes.

Microdots are the primary cause of any

measured/perceived gamut increase, rather than how they are organized.

175 lpi AM 340 lpi XM 21µ 1st order FM

SLIDE 15

What’s better: fine AM, XM or FM?

All are good – especially at rendering details.

XM & FM can have the same size minimum dot. FM screens tend to show noise or grain in flat tints AM & XM tend to show smoother flat tints

But fine AM can clip (posterize) in highlights

340 lpi XM 21µ 2nd order FM 21µ 1st order FM 300 lpi AM

SLIDE 16

Take a closer look for yourself…

:Sublima

Technology Overview

Printed using only

CMYK – no spot colors!

Overall line screen used

340 lpi :Sublima.

Also compares 210, 240 & 280

:Sublima, and shows 21 micron :CristalRaster & 175 ABS.

SLIDE 17