- although one can achieve many effects in image editing programs such as
Photoshop that simulate the effect of many of these filters, it is usually
better to get the image right in the camera without need for image
manipulation in the computer which tends to degrade the image in other ways.
- some effects cannot be easily reproduced in Photoshop such as polarising
- even more important is the problem that digital cameras have limited
dynamic range and it is very easy to burn out highlights and irreversibly
lose detail in them. Thus graduated optical filters become even more
important in digital photography if one wishes to retain cloud details in a
scene, or perhaps the brightly lit end of a room or corridor. There is still
the problem though of objects that pass from dark to light areas potentially
revealing the position of the graduated filter cutoff line.
- One thing that no amount of Photoshop can fix is shooting into the sun, if you have the sun on the horizon and shoot straight into it you will end up with flare and a general washout of colour, use a ND Grad to block that light and the tonal range is captured again.
- adequate lens hoods are imperative to reduce lens flare, particularly when
shooting into the light source.
- prices are approximate from Vanbar
2005 to give you an idea of comparisons.
- what would I use for digital photography?
- UV filter to protect lens - consider removing it to take critical
photos esp. those into a light source when flare needs to be controlled.
Not much point spending $A70 on a filter to protect a $A200 lens though,
and no point taking photos through a $A20 filter when using a $A1000
lens. So if you are going to remove the filter to take your photos, you
can buy a cheap one, otherwise buy a multicoated expensive one.
- circular polariser filter to darken blue skies and reduce reflections.
- circular ND filter to allow longer exposures such as needed to produce
flowing water motion.
- ND graduated filters of the square design (eg. Cokin, Lee) to prevent
the sky getting blown out. Don't bother with circular ones as you can't
adjust them up and down for horizons, etc.
- maybe an R72 infrared filter if you want to try infrared digital
- screw-on filters:
- these are the usual ones available
- slide in filters:
- these are usually square glass or resin filters which slide into a
holder which has been screwed onto your lens filter thread.
- this enables the vertical or horizontal position of the filter to be
adjusted to suit which is critical when using graduated filters that are
used to darken the sky, etc.
- these systems usually incorporate lens hoods that attach to the
- Cokin have 4 filter systems:
- "A series":
- 67mm filters for lenses with filter threads up to 62mm and
focal lengths >= 35mm;
- cost $A20ea
for basic, to $A30 for graduated & up to $A50-60 for some
- "P series":
- "Z Pro":
- 100mm wide filters for lenses with filter threads up to 96mm
and focal lengths >= 20mm;
- "XPro" -
- 130mm wide filters for lenses with filter threads up to 118mm
and focal lengths >= 15mm;
- professional series. $A90 basic; $A136
- Singh-Ray filters:
- Galen Rowell 120x84mm graduated soft-step & hard-step ND
filters (fit Cokin P)
- Daryl Benson
reverse ND graduated filters with max. ND at horizon for sunset
then gradates less for sky.
- Gold'n'Blue Polarizer $US179 - changes the colour in polarised
light only, thus quite natural
- colour intensifiers
- other professional systems:
- Lee glass filters 84mm to fit Cokin P
- "Foundation kit" filter holder $A143 & lens
adapter ring $A47
- bellows lens hoods: $A220-440
- 100mm resin /105mm glass- $A130 basic; $A400 linear
polariser; $A700 circular polariser;
- 150mm - $A176 grad;
- 100mm polyester: $A44 colour compensation;
- 150mm polyester: $A85 colour compensation;
- lighting filters:
- filters that slide in front of professional light sources such as
- various filter packs $A55/pack
Filters for colour photography:
- lens protection filters:
- UV or 1A skylight filter:
- blocks UV light, reducing bluishness in outdoor shots, while acting as a protector for your valuable
- some people even use a 81A warming filter for most of their photos
even in digital
- polarising filter:
- great for minimising glare/reflections on glass, water & making
the blue sky deeper, although the effect is maximal in the sky which is
90deg. from the sun
- many AF SLR cameras require circular polarisers, while other cameras can
use the cheaper linear polarisers.
- sky effect of polariser filters can be simulated in Adobe Photoshop®
- polariser filters were often used to increase saturation in color
films such as Kodak color films but are usually not needed with modern
high saturation color films such as Fuji's Velvia & indeed often
cause sky to appear a less flattering version of black.
- "warm polarisers" have a 81A built-in with the polariser so
you don't have to use both which may otherwise cause vignetting with
wide angle lenses.
- see http://www.dpfwiw.com/polarizer.htm
- see http://micro.magnet.fsu.edu/optics/lightandcolor/polarization.html
- colour temperature correction filters:
- not needed with digital cameras as these can usually be set to
correct white balance, but are important in film photography where light
source is not that for which the film was designed.
- for serious colour film photography when colour temperature is
important, one may need to consider a colour temperature meter but these
are very expensive.
- all colour conversion filters require an increase in exposure, usually
by 1/3rd - 2/3rd stops, although the bluish 80 series require 1-2 stops
- conversion filters:
||use in daylight
||use with 3400K
||use with 3200K
||use with clear flashbulb 3800K
||noon daylight, flash
|| no filter needed
||photo lamps 3400K
||no filter needed
||no filter needed
- conversion filters are often used to create a warmer mood such as
use of an 81A
- for more details see colour temperature
- some use a Tiffen 812 to warm and reduce green when shooting portraits
under a tree with a film camera.
- neutral density filters:
- useful to allow longer exposure times, eg. to create a sense of water
movement in bright sunlight
- graduated filters can be used to darken the sky to help retain detail
in clouds or just create a more moody effect.
- graduated colour filters:
- filters that enable one to alter the colour of the sky, to make it
warmer or perhaps colder.
- not needed for digital photography as ND probably is a safer bet as
can use Photoshop to apply a graduated color.
- special effects filters:
- fog, soft, diffusion
- spot, vignetting
- star effects on specular highlights
- most of these can be simulated in Photoshop
- infra-red filters:
- only allow infra-red light through to create special false-colour
effects or dramatic, eerie B&W effects
- see infra-red photography
- lighting filters:
- filters on flash guns or light sources can create great effects,
particularly when used on the background. Combinations of blue &
amber lights are often very effective here.
Filters for B&W photography:
- any of the filters for colour photography may be used
- these colored filters are of little use in digital photography as
Photoshop can mimic these see here
- colour filters to alter the gray-scale rendering of the image and thus
- often used to give natural rendition of blue sky, water,
foliage & landscape scenery
- tones down skin blemishes and ruddiness in daylight portraits, and
results in soft skin tones as well as intensified blonde hair.
- often used for portraiture for skin tone rendition esp.
outdoor against a blue sky
- deep yellow:
- dark water in marine scenes with blue sky
- diminishes skin blemishes and freckles in artificial light. It
also darkens eye colors and lightens lip colors.
- used for contrast control in aerial IR photography.
- enhanced texture of stone, sand, etc when
sunlit under blue sky
- enhanced texture of stone, sand, etc when
sunlit under blue sky
- dramatic darkening of blue sky making dramatic clouds
- darkens sky-illuminated shadows considerably increasing contrast
- darken diffuse reflection from foliage
- makes daylight scenes appear as though photographed at night
- very pale skin tones
- sky brightness rendering of clear blue sky on panchromatic film:
- no filter => lighter than correct
- Wratten 8 (yellow) => natural
- Wratten 15 (deep yellow) => darker
- Wratten 23A (light red) => quite dark
- Wratten 25 (medium red) => very dark
- Wratten 29 (deep red) => almost black
- infra-red film with Wratten 25 or infra-red filter with digital
camera => black
- to darken the following subjects:
- yellow => blue filter
- yellow-green => blue or magenta filter
- green => blue, magenta or red filter
- cyan => red filter
- blue => red, green, or yellow filter
- magenta/violet => green/yellow filter
- orange or red => green, cyan or blue filter
- see also filters for IR photography
- filters often require an increase in exposure to allow for the reduction
in light, and this exposure increase required is often expressed as a
"filter factor" such that a filter factor of 2x means exposure
must be doubled, ie. increased by 1 stop, and filter factor of 4x means 2
stops increase needed, while 8x requires 3 stops.
||1 & 1/3rd
||1 & 1/2
||1 & 2/3
||2 & 1/3
- polarising filters usually have a filter factor of 2.5, and thus require 1
& 1/3rd stops increase.
- filter factors for color filters in B&W depend on which light source
is used, whether daylight or tungsten, as bluish filters will have a much
greater filter factor for tungsten light (eg. in this case, double that for
daylight film), while the reverse is true for red filters.
- for daylight, approx. filter factors are:
- yellow 1.5; deep yellow 2; yellow-green 4; green 5-6; light red 6;
red 8; 25A deep red 16; blue 6; 47B deep blue 8; 61 deep green
- neutral density filters are often given a different system:
- 0.30 = 50% reduction in light = 2.0 filter factor = 1 stop
- 0.60 = 75% reduction in light = 4.0 filter factor = 2 stops
- 0.90 = 87% reduction in light = 7.7 filter factor = ~3 stops
- 1.00 = 90% reduction = 10.0 filter factor = 3 & 1/3rd stops
- 2.00 = 99% reduction = 100 filter factor = 6 & 2/3rd stops
- it is important to avoid distorting the filter ring as this may make
- don't screw on too tight
- consider using graphite on thread first
- some shops sell filter wrenches that apply equal pressure
circumferentially, alternatively can use:
- Jens Birch's method:
- "I have found those 'cable strips' made from stiff plastic which are
intended for collecting bundles of cables very versatile. I have made
my own wrench from one with a suitable size. In order to get a good
grip, I put a rubber band of the same width as the filter around the
filter rim before putting the cable strip around it. I have never
failed separating filters since I started with that method."