December 2001
FACT SHEET
CONTRAST
CONTROL
CONTRAST CONTROL
FOR ILFORD MULTIGRADE VARIABLE CONTRAST PAPERS
Contrast control with ILFORD MULTIGRADE papers
can be achieved in several ways. These include
the ILFORD MULTIGRADE hand filters and the
ILFORD MULTIGRADE 600 equipment. Contrast
can also be controlled with other variable contrast
enlarger heads and with colour enlargers.
CONTRAST RANGE
This section describes how MULTIGRADE papers
give different contrast levels. For practical
information on selecting contrast levels turn to the
next pages.
resultant curve has a very much wider exposure
range and is thus of low contrast.
By varying the proportion of blue to green light, a
contrast range between these two extremes can be
obtained. The simplest way of controlling the
colour of the light reaching the emulsion during
exposure is by the use of filters: a magenta filter
absorbs green light and transmits blue; a yellow
filter absorbs blue light and transmits green. In this
way, high and low contrast images can be made.
Exposure to blue light
MULTIGRADE papers are coated with an emulsion
which is a mixture of three separate emulsions.
Each emulsion is a basic blue sensitive emulsion to
which is added different amounts of green
sensitising dye. Thus, part of the mixed emulsion is
sensitive mainly to blue light, part to blue light
with some sensitivity to green light and part to
both blue and green light.
All parts of the emulsion have the same contrast.
They also all have the same speed to blue light,
but naturally, the part of the emulsion with only a
small amount of green sensitising dye has a low
speed (that is, is less sensitive) to green light.
Density
All chloro-bromide (black and white) emulsions are
blue sensitive with a slight sensitivity to green light.
To make an emulsion sensitive to colours in
addition to blue, sensitising dyes need to be
added.
Relative log exposure
A
B
C
D
combined curve
dyed emulsion I
dyed emulsion II
dyed emulsion III
Exposure to green light
When the paper is exposed to green light, only
the parts of the emulsion with the larger amounts
of green sensitising dye react initially. This is
because the three emulsions have very different
sensitivities to green light. This image is of low
contrast because of the additive effect produced
by three emulsions with different speeds to green
light, but with the same inherent contrast. The
Page 1 of 4
Density
When the paper is exposed to blue light, all parts
of the emulsion react and contribute equally to the
final image. This image is of high contrast because
of the additive effect produced by three emulsions
with the same speed and contrast. The resultant
curve has a narrow exposure range and is thus of
high contrast.
Relative log exposure
A
B
C
D
combined curve
dyed emulsion I
dyed emulsion II
dyed emulsion III
CONTRAST CONTROL
MULTIGRADE FILTERS
The twelve MULTIGRADE filters are numbered
00–5 in 1/2 steps, with the lowest filter number
corresponding to the softest contrast.
Filters are available in sets of filters 8.9x8.9cm
(31/2x31/2 inches) and 15.2x15.2cm (6x6 inches).
They can be used above or below the lens and
can be cut to fit the enlarger filter drawer. Filter
sizes 30x30cm (11.8x11.8 inches) are available
to special order.
A filter kit is available for below the lens use. The
kit comprises 12 mounted contrast filters, a
mounted safelight filter and a filter holder.
MULTIGRADE filters are very easy to use: no
complicated calculations are needed when
changing from one filter to another. The exposure
time for filters 00–31/2 is the same; that for filters
4–5 is double.
MULTIGRADE 600 EQUIPMENT
The MULTIGRADE 600 professional exposing
system is a very convenient means of exposing
MULTIGRADE papers over a wide contrast range
of 00 to 5.
It works on the closed loop system, with a single
pre-warmed lamp, to give repeatable results, even
at high contrasts.
The light output is precisely controlled by the
motorised shutter. The motorised filters give
contrast control in 1/10 grade steps over grades 0
to 5. The head has five programmable paper
channels (four pre-set for ILFORD MULTIGRADE
papers). It also gives true white light for
composition, focusing and exposure.
Once calibrated, the exposure probe automatically
calculates the exposure and contrast needed for
each negative. It can be used under normal
safelight conditions.
The MULTIGRADE 600 system can also be used
with most automatic roll easels.
The MULTIGRADE 600H enlarger head replaces
the standard lamphouse on the most popular
professional enlargers. The control unit, power
supply and probe complete the system.
There are two versions of the MULTIGRADE 600H
enlarger head. The medium format version is
suitable for the Durst M805 enlarger. The standard
format version is suitable for other enlargers
including the Durst L1200, DeVere 504, Omega D
and Beseler 45. The enlarger head fits directly in
place on the Durst M805 and Durst L1200
enlargers. An adaptor kit is needed with other
enlargers.
Page 2 of 4
MULTIGRADE 600 – medium format
Enlarger head
Power supply
Control unit
Exposure probe
Light mixing boxes*
MULTIGRADE
(for negatives
MULTIGRADE
MULTIGRADE
MULTIGRADE
MULTIGRADE
35mm
6x6cm
6x9cm
600
up to 6x9cm(
600H
600S
600C
600P
Optional equipment
Footswitch
MULTIGRADE 600F
*At least one light mixing box is needed for a complete
system.
MULTIGRADE 600 – standard format
Enlarger head
Power supply
Control unit
Exposure probe
Light mixing boxes*
MULTIGRADE
(for negatives
MULTIGRADE
MULTIGRADE
MULTIGRADE
MULTIGRADE
35mm
6x7cm
4x5inches
600
up to 4x5inches)
600H
600S
600C
600P
Optional equipment
Footswitch
MULTIGRADE 600F
*At least one light mixing box is needed for a complete
system.
OTHER VARIABLE CONTRAST
ENLARGER HEADS
The contrast of MULTIGRADE papers can be
controlled with the range of variable contrast
enlarger heads that are currently available. Some
of these are easier to use than others, and several
give excellent results.
Many manufacturers make variable contrast heads
for their enlargers which are specially designed for
use with MULTIGRADE papers. Enlarger heads that
have been designed in conjunction with ILFORD
include those from De Vere, Dunco, Kaiser, Leitz,
LPL and Meopta.
For use with MULTIGRADE papers, follow the
instructions provided by the enlarger manufacturer.
CONTRAST CONTROL
CONTRAST CONTROL
USE OF COLOUR HEADS
By adjusting the yellow and magenta filtration on
colour heads, it is possible to obtain a wide
contrast range with MULTIGRADE papers.
However, the maximum contrast will be slightly
lower as the filters used in colour heads are
optimised for use with colour paper and not with
variable contrast paper. The suggested filtration in
the following tables can only be a guide, because
individual enlargers vary. The actual filtration for a
particular enlarger must be determined by trial.
Filtration types used in colour
enlargers
From the table below, select the type of filtration
needed according to the enlarger type.
Durst
Dunco
Durst
Kaiser
Kienzle
Leitz
Lupo
Kodak
Advena
Beseler
Chromega
De Vere
Fujimoto
IFF
Jobo
LPL
Omega
Paterson
Simmard
Vivitar
Meopta
Meopta
Single colour filter settings
From the table below, read off the approximate
filtration needed for each contrast step. However,
as the yellow and magenta filters have not been
arranged to equalise exposures, new exposure
times will have to be recalculated when the
contrast is changed.
If you are using a Durst enlarger, or one that uses
Durst filtration values, choose the suggested
settings depending on whether the maximum
magenta setting on your enlarger is 170M or
130M.
MULTIGRADE Durst
Durst
Kodak
Meopta
filter
(max
(max
170M)
130M)
00
150Y
120Y
199Y
150Y
0
90Y
70Y
90Y
90Y
1/2
70Y
50Y
70Y
70Y
1
55Y
40Y
50Y
55Y
11/2
30Y
25Y
30Y
30Y
2
0
0
0
0
21/2
20M
10M
5M
20M
3
45M
30M
25M
40M
31/2
65M
50M
50M
65M
4
100M
75M
80M
85M
41/2
140M
120M
140M
200M
5
170M*
130M
199M
–
*Some enlargers in this group have a maximum magenta
setting higher or lower than 170M. For these enlargers, set
the highest possible magenta value as an approximate
equivalent to filter 5.
Page 3 of 4
Dual colour filter settings
From the table below, read off the approximate
filtration needed for each contrast step. Dual
filtration values usually need longer exposure times
than single filtration values, but should need less
adjustment to exposure times when changing
contrast.
MULTIGRADE Durst
Durst
filter
(max
(max
170M)
130M)
00
115Y/0M 120Y/0M
0
100Y/5M 88Y/6M
1/2
88Y/7M 78Y/8M
1
75Y/10M 64Y/12M
11/2
65Y/15M 53Y/17M
2
52Y/20M 45Y/24M
21/2
42Y/28M 35Y/31M
3
34Y/45M 24Y/42M
31/2
27Y/60M 17Y/53M
4
17Y/76M 10Y/69M
41/2
10Y/105M 6Y/89M
5
0Y/170M 0Y/130M
Kodak
162Y/0M
90Y/0M
78Y/5M
68Y/10M
49Y/23M
41Y/32M
32Y/42M
23Y/56M
15Y/75M
6Y/102M
0Y/150M
–
Leitz
Focomat
V35
135Y/6M
105Y/12M
77Y/11M
67Y/17M
52Y/28M
39Y/43M
32Y/51M
23Y/62M
14Y/79M
10Y/95M
15Y/154M
0Y/200M
EXPOSING LIGHT SOURCES
MULTIGRADE papers are designed for use with
most enlargers and printers, that is, those fitted
with either a tungsten or tungsten halogen light
source. They are also suitable for use with cold
cathode (cold light) light sources designed for
variable contrast papers.
Cold cathode enlarger heads
Enlargers fitted with a cold cathode (cold light)
head which has been designed for use with
variable contrast papers can give a full contrast
range on MULTIGRADE papers.
However, although a full contrast range may be
available, it might not be evenly spaced. Also, in
some cases, a full contrast range may not be
available – it depends on the cold cathode lamp
used.
The following chart gives a guide to the contrast
range of MULTIGRADE papers when exposed
using MULTIGRADE filters with a conventional
tungsten enlarger head and with an Aristo head
fitted with an Aristo W45 cold cathode lamp.
With the Aristo W45 lamp, extra yellow filtration
was also added – CC40Y – as recommended by
Aristo. It can be seen that a full contrast range can
be achieved, but the grade intervals are bunched
towards the hard contrast end.
CONTRAST CONTROL
Exposure factors for an Aristo head
fitted with the Aristo W45 lamp + 40Y filter
MULTIGRADE filters
00
0
1/2
1
11/2
2
21/2
3
31/2
4
41/2
5
to
00
1.00
1.07
1.10
1.15
1.17
1.26
1.38
1.70
1.62
0.98
1.00
1.12
1/2
0
0.93
0.91
1.00
0.98
1.02
1.00
1.07
1.05
1.10
1.07
1.18
1.15
1.29
1.26
1.59
1.55
1.51
1.48
0.96
0.93
0.93
0.91
1.05
1.02
1
11/2
0.87
0.85
0.93
0.91
0.96
0.93
1.00
0.98
1.02
1.00
1.10
1.07
1.20
1.18
1.48
1.45
1.41
1.38
0.89
0.87
0.87
0.85
0.98
0.96
2
21/2
0.79
0.72
0.85
0.78
0.87
0.79
0.91
0.83
0.93
0.85
1.00
0.91
1.10
1.00
1.35
1.23
1.29
1.18
0.81
0.74
0.79
0.73
0.89
0.81
3
31/2
0.59
0.62
0.63
0.66
0.65
0.68
0.68
0.71
0.69
0.72
0.74
0.78
0.81
0.85
1.00
1.05
0.96
1.00
0.60
0.63
0.59
0.62
0.66
0.69
4
41/2
0.98
1.00
1.05
1.07
1.07
1.10
1.12
1.15
1.15
1.18
1.23
1.26
1.35
1.38
1.66
1.70
1.58
1.62
1.00
1.02
0.98
1.00
1.10
1.12
5
0.89
0.96
0.98
1.02
1.05
1.12
1.23
1.51
1.45
0.91
0.89
1.00
from
When changing contrast with an Aristo head fitted
with the Aristo W45 lamp + 40Y filtration, the
exposure has to be recalculated. This is because
the MULTIGRADE filters (and other manufacturers’
filters) are designed for use with tungsten enlarger
heads. The table gives the exposure factors for
MULTIGRADE IV RC DeLuxe paper. It can also be
used as a guide for other MULTIGRADE papers.
For example, if a print of correct density has been
made using filter 2 but it is decided that the
contrast of filter 3 is needed, multiply the exposure
given for filter 2 by 0.74.
Cold cathode (cold light) heads not designed for
variable contrast papers and pulsed xenon light
sources may give a reduced contrast range. The
MULTIGRADE 00 filter is particularly useful with
these light sources as it significantly extends the
contrast range available. Alternatively, some
additional yellow filtration, up to 70Y, may help.
The contrast range will depend on the spectral
characteristics of the light source used. The only
way to determine the contrast range available with
each model of enlarger is to carry out a practical
test.
DIFFUSER v CONDENSER ENLARGERS
MULTIGRADE papers are designed for use with
both diffuser and condenser enlargers. However,
because of the different types of illumination there
can be a contrast difference between the two
types. In practical terms with most negatives,
condenser enlargers give about an extra grade of
contrast compared with a diffuser enlarger. This
contrast difference, though, depends on the
amount of silver left in the negative. Thus there is
little change of contrast between the enlarger types
for very pale, flat negatives and also for the dye
image of ILFORD XP2 SUPER negatives.
A wide range of fact sheets is available which describe and
give guidance on using ILFORD products. Some products in
this fact sheetmight not be available in your country
Page 4 of 4
ILFORD Imaging UK Limited, Town Lane, Mobberley,
Knutsford, Cheshire WA16 7JL, England
www.ilford.com
94055.GB.www
December 2001