Wratten
number
|
Visible color
|
Filter factor
or alternate
designation
|
F-Stops correction
|
Uses and characteristics
|
1A
|
|
|
|
Called a skylight filter, this absorbs ultraviolet
radiation, which reduces haze in outdoor landscape photography.
|
2A
|
pale yellow
|
|
|
Absorbs ultraviolet radiation. longpass filter blocking
wavelengths below 405 nm
|
2B
|
pale yellow
|
|
|
Absorbs ultraviolet radiation, slightly less than #2A.
longpass filter blocking wavelengths below 395 nm
|
2C
|
|
|
|
Absorbs ultraviolet radiation. longpass filter blocking
wavelengths below 390 nm
|
2E
|
pale yellow
|
|
|
Absorbs ultraviolet radiation, slightly more than #2A.
longpass filter blocking wavelengths below 415 nm
|
3
|
light yellow
|
|
|
Absorbs excessive sky blue, making sky look slightly darker
in black and white images. longpass filter blocking wavelengths
below 440 nm
|
4
|
yellow
|
|
|
longpass filter blocking visible wavelengths below 455 nm
|
6
|
light yellow
|
K1
|
|
not a longpass filter
|
8
|
yellow
|
K2
|
|
Absorbs more blue than #3. longpass filter blocking visible
wavelengths below 465 nm
|
9
|
deep yellow
|
K3
|
|
Absorbs more blue than #8. longpass filter blocking visible
wavelengths below 470 nm
|
11
|
yellowish-green
|
X1
|
|
Color Correction. not a longpass filter
|
12
|
deep yellow
|
Minus blue
|
|
Minus blue filter; complements #32 minus-green and #44A
minus-red. Used with Ektachrome or Aerochrome Infrared films to
obtain false-color results. Used in ophthalmology and optometry in
conjunction with a slit-lamp and a cobalt blue light to improve
contrast when assessing the health of the cornea and the fit of
contact lenses. longpass filter blocking visible wavelengths below
500 nm
|
15
|
deep yellow
|
G
|
|
Darkens the sky in black and white outdoor photography.
longpass filter blocking visible wavelengths below 510 nm
|
16
|
yellow-orange
|
|
|
Performs like #15, but more so; longpass filter blocking
visible wavelengths below about 520 nm
|
18A
|
visually opaque
|
|
|
Based on Wood's glass, transmits small bands of ultraviolet
radiation and infraredradiation.
|
18B
|
very deep violet
|
|
|
Similar to 18A but with wider bands of transmittance in both
the ultraviolet and infrared, a less 'pure' filter.
|
21
|
orange
|
|
|
Contrast filter for blue and blue-green absorption. longpass
filter blocking visible wavelengths below 530 nm
|
22
|
deep orange
|
|
|
Contrast filter, greater effect than #21. longpass filter
blocking visible wavelengths below 550 nm
|
23A
|
light red
|
|
|
longpass filter blocking visible wavelengths below 550 nm
|
24
|
red
|
|
|
Used for color separation of
Kodachrome transparency film, complements #47B and #61. longpass
filter blocking visible wavelengths below 575nm. Red for 'Two
Color Photography' (daylight or tungsten). White flame arc
tri-color projection.
|
25
|
red tricolor
|
A
|
|
Used for color separation and infrared photography longpass
filter blocking below 580 nm.
|
26
|
red
|
|
|
longpass filter blocking below 585 nm
|
29
|
deep red
|
F
|
|
Used for color separation, complements #47 and #61. In black
and white outdoor photography makes blue skies look very dark,
almost black. In infrared photography, blocks much visible light,
increasing the effect of the infrared frequencies on the picture.
longpass filter blocking below 600 nm.
|
32
|
magenta
|
|
|
Minus-green. Complements #12 minus-blue and #44A minus-red.
|
34A
|
violet
|
|
|
Used for minus-green and plus-blue separation.
|
38A
|
blue
|
|
|
Absorbs red, some UV and some green light.
|
40
|
light green
|
|
|
Green, for two color photography (tungsten).
|
44
|
light blue-green
|
|
|
minus-red filter with much UV absorption.
|
44A
|
light blue-green
|
|
|
minus-red, complements #12 is minus-blue and #32
minus-green.
|
47
|
blue tricolor
|
C5
|
|
Used for color separation. Complements #29 and #61.
|
47A
|
light blue
|
|
|
By removing lots of light that is not blue, blue and purple
objects show a broader range of colors. Used for medical
applications that involve making dyes fluoresce.
|
47B
|
deep blue tricolor
|
|
|
Used for color separation. It is
also commonly used to calibrate video monitors while using SMPTE
color bars.
|
50
|
deep blue
|
|
|
|
56
|
light green
|
|
|
|
57
|
green
|
|
|
Green for 'Two Color Photography' (daylight).
|
58
|
green tricolor
|
B
|
|
Color separation.
|
60
|
green
|
|
|
Green for two color photography' (tungsten).
|
61
|
deep green tricolor
|
N
|
|
Color separation, complements #29 and #47.
|
70
|
red
|
|
|
Used for color separation and infrared photography longpass
filter blocking below 650 nm.
|
80A
|
blue
|
4
|
2
|
Color Conversion. Raises the color temperature, causing a
3200 K tungsten-lit scene to appear to be daylight lit,
approximately 5500 K. This allows use of a daylight balanced film
with tungsten lighting.
|
80B
|
blue
|
3
|
1+2/3
|
Similar to 80A; 3400 K to 5500 K.
|
80C
|
blue
|
2
|
1
|
Similar to 80A; 3800 K to 5500 K. Typically used so that
old-style flashbulbs can be used on a daylight film.
|
80D
|
blue
|
1.5
|
1/3
|
Similar to 80A; 4200 K to 5500 K.
|
81A
|
pale orange
|
1.4
|
1/3
|
Warming filter to decrease the color temperature slightly;
this can also be used when shooting tungsten type B film (3200 K)
with 3400 K photoflood lights. The opposite of 82A.
|
81B
|
pale orange
|
1.4
|
1/3
|
Warming filter, slightly stronger than 81A. The opposite of
82B.
|
81C
|
pale orange
|
1.5
|
1/3
|
Warming filter, slightly stronger than 81B, opposite of 82C.
|
81D
|
pale orange
|
|
|
Warming filter, slightly stronger than 81C.
|
81EF
|
pale orange
|
|
1/3
|
Warming filter, stronger than 81D.
|
82A
|
pale blue
|
1.3
|
1/3
|
Cooling filter to increase the color temperature slightly.
The opposite of 81A.
|
82B
|
pale blue
|
1.4
|
2/3
|
Cooling filter, slightly stronger than 82A and opposite of
81B. Can also be used when shooting tungsten type B film (3200 K)
with household 100 W electric bulbs (2900 K).
|
82C
|
pale blue
|
1.5
|
2/3
|
Cooling filter, slightly stronger than 82B and opposite of
81C.
|
85
|
amber
|
1.5
|
2/3
|
Color conversion, the opposite of the 80A; this is a warming
filter that takes an outdoor scene lit by sunlight (which has a
color temperature around 5500 kelvins) and makes it appear to be
lit by tungsten incandescent bulbsaround 3400 K. This allows an
indoor balanced film to be used to photograph outdoors. These
filters were used in Super 8 movie cameras that were designed to
use Tungsten film.
|
85B
|
amber
|
1.5
|
2/3
|
Similar to 85; converts 5500 K to 3200 K.
|
85C
|
amber
|
1.5
|
|
Similar to 85; converts 5500 K to 3800 K.
|
85N3
|
amber
|
|
|
Neutral density of 1 stop + color conversion, the opposite
of the 80A; this is a warming filter that takes an outdoor scene
lit by sunlight (which has a color temperature around 5500
kelvins) and makes it appear to be lit by tungsten incandescent
bulbs around 3400 K. This allows an indoor balanced film to be
used to photograph outdoors.
|
85N6
|
amber
|
|
|
Neutral density of 2 stops + color conversion, the opposite
of the 80A; this is a warming filter that takes an outdoor scene
lit by sunlight (which has a color temperature around 5500
kelvins) and makes it appear to be lit by tungsten incandescent
bulbs around 3400 K. This allows an indoor balanced film to be
used to photograph outdoors.
|
85N9
|
amber
|
|
|
Neutral density of 3 stops + color conversion, the opposite
of the 80A; this is a warming filter that takes an outdoor scene
lit by sunlight (which has a color temperature around 5500
kelvins) and makes it appear to be lit by tungsten incandescent
bulbs around 3400 K. This allows an indoor balanced film to be
used to photograph outdoors.
|
87
|
opaque
|
|
|
Passes infrared but not visible frequencies. blocks
wavelengths below 740 nm
|
87A
|
opaque
|
|
|
Passes infrared but not visible frequencies. blocks
wavelengths below 880 nm
|
87B
|
opaque
|
|
|
Passes infrared, blocks visible frequencies. blocks
wavelengths below 820 nm
|
87C
|
opaque
|
|
|
Passes infrared, blocks visible frequencies. blocks
wavelengths below 790 nm
|
88
|
opaque
|
|
|
Passes infrared, blocks visible wavelengths below 700 nm.
|
88A
|
opaque
|
|
|
Passes infrared, blocks visible frequencies. below 720 nm.
|
89B
|
near-opaque red
|
R72
|
|
Passes infrared, longpass filter blocking visible
wavelengths below 690 nm (very deep red). Aerial photography
is one use.
|
90
|
dark grayish amber
|
|
|
Used for viewing scenes without color before photographing
them, in order to assess the brightness values. Not used for
actual photography.
|
92
|
red
|
|
|
color densitometry. longpass filter blocking visible
wavelengths below 625 nm
|
93
|
green
|
|
|
color densitometry.
|
94
|
blue
|
|
|
color densitometry.
|
96
|
gray
|
varies
|
|
neutral density filter. Blocks all frequencies of visible
light approximately evenly, making scene darker overall. Available
in many different values, distinguished by optical density or by
filter factor.
|
98
|
blue
|
|
|
Like a #47B plus a #2B filter.
|
99
|
green
|
|
|
Like a #61 plus a #16 filter.
|
102
|
yellow-green
|
|
|
Color conversion; makes a barrier-level type photocell
respond as a human eye would.
|
106
|
amber
|
|
|
Color conversions; makes an S-4 type photocell respond as a
human eye would.
|