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                Filters

 

                        By Eugene Struthers

 

A comprehensive guide to filters.

 

Filters

 

If you are trying to create images with atmosphere and a diversity in colour contrast. Then I would recommend purchasing filters to enhance depth and give your images a rich warm tone.

 

These are classified into four categories:-

 

General, Coloured and Special effect filters and Prod1 filters (designed exclusively for digital cameras.

 

The different types of filter.

 

Polarizers

 

If you don't have a polarizer at this stage of your photography career, then I would recommend purchasing one. A polarizer is ideal for preventing reflections and glare when doing an outdoor shoot. Out door images of the sky without a polarizer appear light blue and tepid. By adding a polarizer the sky will appear to have more depth in colour and the polarizer will highlight the richness in the tones and their individual density. They are a worthy but expensive investment, and can only add that professional glossy crystal appearance to an image.

 

Example:- Tiffen circular Polarizer, Cokin 164 Circular Polarizer

 

 

General filters

 

UV/ Skylight / Haze

 

These type of filters are primarily used to reduce a blue haze caused by UV. They protect the lens and prevent dust, scratches and moisture from having an effect on the images end result. This group includes everyday filters which can be left on your lenses, such as Skylight 1B, UV and Polarising. These are the first filters that every photographer should ensure they own. Skylight and UV filters should be constantly fitted to a lens to give improved clarity and colour balance as well as offering protection to your lens. Polarising filters have several uses such as ellminating unwanted reflections, increasing colour saturation and enhancing contrast. As to whether you should use Circular Polarising or Linear Polarising filters with your camera, we recommend that you refer to the detailed explanation later in this catalogue.

 

UV (0)

 

Absorbs the ultraviolet rays which often makes outdoor photographs hazy and indistinct. A multi-purpose fine-weather filter for colour as well as black and white films. Also, serves as a permanent lens protector.

 

Skylight 1B

 

The absorption peak is in the range which corresponds to the film's green spectrum. This means outstanding outdoor shots with superb color balance and clarity under all conditions. Also keeps skin tones free of colored reflections from nearby objects such as the shade of trees.Reduces the excessive bluishness that frequently occurs in outdoor color photography, especially in open shade under a clear, blue sky. 

 

 

Neutral

 

Mounted in an ULTRA slim 3mm ring, this is the ultimate in clear filters. Made from completely transparent superior grade optical glass, it will not affect the colour balance or performance of your lenses in the slightest. However, constant use will protect your valued lenses from expensive front element damage which could be caused by dirt, knocks and scratches.

 

PL/PL-Cir

 

Light rays which are reflected by any surface become polarised and polarising filters are used to select which light rays enter your camaras lens. PL (Linear Polarising) and PL-CIR (Circular Polarising) filters have the same effect, but it is important that you choose the correct version for your camera. They allow you to remove unwanted reflections from non-metallic surfaces such as water, glass etc. They also enable colours to become more saturated and appear clearer, with better contrast. This effect is often used to increase the contrast and saturation in blue skies and white clouds. HOYA's polarising filters do not affect the overall colour balance of a shot.

 

 

UV-PL-Cir

 

A revolutionary 'hybrid' design which combines the effect of two different filters in one ring. This filter eliminates ultraviolet rays to remove haze from outdoor shots as well as polarising the light to remove reflections, and increase colour saturation, without affecting the overall colour balance. Fitted in a slim rotating 5mm ring, it will be invaluable to landscape and other photographers who need avoid vignetting with wide angle lenses.

 

Example:- Hoya skylight 1B

 

Neutral Density (ND)

 

This ideal for professional photographers that want to limit the amount level of light in a given scene, this is often complimented to attain a wided depth of field and a slower shutter speed. As in the case when shooting waterfalls. To achieve a romantic feel to to this type of image you will need to have a slower shutter speed with a two-stop neutral density ( .6 ND to hold back the light and get a long exposure). These are available as .3 (1 stop), .6 (2 stop), .9 (3stop).

 

Coloured filters

 

They are used for colour correction of different light sources when using colour film, or for controlling contrast with Black & White film. Color correction filters are important as colour films do not have the flexibility of the human eye to automatically adjust to different situations. Black & White films register colours as shades of grey and the rendition of each colour in a scene is important, so filters can be used to control this. The colour of the glass used in all these filters is carefully controlled and to reduce the possibility of colour shift over a period of time, such high-quality filters are coated or multicoated on both sides. This maintains the desired effect and gives a long service life.Warming filter.

 

These type of filter add a light brown tint to the image, to add and stimulate the golden glow of the late afternoon sun. There are generally three types of warming filters most photographers stick by. These are classified as:- 81A (lightest), 81B (medium) and 81C (strongest). The 81A is great when working outdoors and you need to enhance the green texture and contrasts in leaves and other foliage. The 812 filter is ideal for adding for portraits when you need to add warm skin tones to your model. The novice should start with the 81B warming filter in order to gain experience. These are colour conversion filters for the use of daylight type colour films with artificial light source. 80A increases the colour temperature from 3200°K to 5500°K for the use with 3200°K lamps. 80B increases the colour temperature from 3400°K to 5500°K for the use of photoflood lamps. 80C increases the colour temperature from 3800°K to 5500°K for the use of clear flash bulbs.

 

Example:- Cokin 026 warm 81a, cokin 027 warm 91B, cokin 037 81C

 

FL-D

 

This is a magenta filter that is great for late afternoon shots. It is designed to colour correct artificial fluorescent light. When you are on a late afternoon shoot you will notice that office and street lights appear green and cold. A light magenta filter will make these lights appear pure white and add a clear purple and pink to the sky. Used to correct the greenish tone that appears when daylight type films are used under fluorescent lighting.

 

FL-W is for use with warm white or white type fluorescent lamps.

 

FL-DAY is for use with daylight type fluorescent lamps.

 

It is recommended that auxiliary light sources be used when long exposures become necessary due to insufficient light.

 

Example:- Tiffen FL-D, cokin 046 FL-D, Cokin 035 FL-W

 

85, 85B, 85C

 

These are colour conversion filters for the use of tungsten type colour films in daylight. 85 decreases the colour temperature from 5500°K to 3400°K for the use of Type A colour films. 85B decreases the colour temperature from 5500°K to 3200°K for the use of Type B colour films. 85C decreases the colour temperature from 5500°K to 3800°K. The effect obtained is the same as with daylight type colour films used in daylight.

 

82A, 82B, 82C

 

These are light balancing filters used to increase the colour temperature slightly for a cooler (bluer) tone. Corrects the tendency toward reddish tones. For example, select the 82B when using tungsten Type B colour film (3200°K) with ordinary household 100W electric bulbs (2900°K). These series filters are also used to prevent the reddish tones in early morning or late evening light for natural skin tones. These filters can be used together, but do not mix 81 and 82 series filters since they cancel out each other.

 

81A, 81B, 8C

 

These are light balancing filters used to decrease the colour temperature slightly for a warmer (redder) tone. Corrects the tendency toward bluish tones. For example, the 81A should be selected when using tungsten Type B colour film (3200°K) with photoflood lamps (3400°K) These filters can be used together.

 

K2 (Yellow)

 

Especially useful for clear contrast between blue sky with clouds and foreground. Provides a natural tonal rendition. Often used for subjects at intermediate distances.G (Orange)Increases contrast between reds and yellows. Particularly useful for distant outdoor shots taken with a telephoto lens. Also useful in colour photography for spectacular sunsets, seascapes, etc.

 

25A (Red)

 

Especially effective for increasing contrast. Ideal for dramatic cloud effects in landscapes. Can also be applied creatively in colour and infrared photography.

 

X0 (Yellow, Green), X1 (Green)

 

Used primarily for black and white photography. XO is highly effective for outdoor portraits because red is rendered dark while green appears lighter. Great for correcting skin tones, bringing out facial expressions in close-ups and emphasizing the feeling of liveliness. X1 is highly effective for indoor portraits under tungsten lighting.

 

FOR COLOR FILM:

 

These filters, such as K2 (Yellow), G (Orange), 25A (Red), X0 (Yellow/green) and X1 (Green) are primarily designed for use with Black & White film. However, they can be used with colour film to produce special colour effects.

 

Graduated filters. These are great for shooting landscapes when a bright light is combined with a shady foreground. Use a 2 stop graduated neutral density filter to hold back the light level of the sky to match and be in a similar density tone to the light level of the diverse shades in the colour of the flowers and foliage. Use a graduated tobacco or mauve and blue filter to add a moody brown colour to make a scene look sunnier.

 

Examples:- Cokin 120 gradual G1, cokin 121 Gradual G2, Cokin 127 Graduated mauve M2, Cokin 151 Graduated fog, Cokin 124 Graduated Tobacco,

 

Sepia

 

To give an image which has an old building in the background that old weathered and brown look. A sepia or light sepia filter should be used.

 

Example:- Cokin 045 Sepia

 

Sunset

 

To add a light brown to the foreground and an orange to the sky to enhance and simulate a sunset. A warm / orange graduated filter should be used.

 

Example:- Cokin 197 Sunset 1.

 

Blue & Yellow Polarizer

 

These type of filters add blue or yellow to a scene. It can be used with a graduated mauve or a light warming filter to enhance images with lots of diverse colour contrasts.

 

Example:- Cokin 173 Pola Blue - Yellow

 

Colour enhances (Didymium / Intensifier)

 

This type of filter is great for increasing the colour saturation in a shot. They increase the colour density and enhance the individual colour contrasts as in the case when shooting bright red doors, bright yellow flowers. Also known as a 'didymium' filter, this is used to enhance red, orange and brown subjects to give more colour saturation and contrast, whilst having very little effect on other colours. It can be used in many situations such as architecture where certain building features need emphasising, or for landscapes to enhance foliage and rocky features.

 

Colour Correcting Compensating

 

These are basically filters that hold back some preferred colours whilst allowing the favour of others. Examples of these are the:- CC10G which reduces all colours except green by 10%. This is great for when you only want to increase the colour tones in green foliage. The CC30R is mostly used underwater to enhance and bring out reduced red in images. The CC20M is a dusk filter and is similar in comparison to FL-D. Colour Correcting Compensating available in printing colours:- cyan, magenta and yellow and also in the primary colours:- red, green and blue.

 

80 Blue

 

A range of filters which offers a certain degree of blue for a cooling effect. This is ideal to make snow look colder, an 80C would achieve this desired result.

 

Example:- Cokin 022 Blue 80C

 

Diffuser / Mist / Fog / Soft

 

These soften and add a foggy blur to an image. These are diffusion type filters but DIFFUSER gives a soft-focus effect due to its irregularly uneven surface while DUTO has fine concentric lines etched on its surface.

 

The center of the picture is usually sharp with DUTO but DIFFUSER gives an overall soft-focus effect.Both are particularly effective in portraiture and commercial photography.

 

Color Effects

 

Colour spot coloured glass filter with a hole in its center. Available in yellow, green, red and grey. The central image stands out clearly while the background appears the colour of the filter.

 

Intensifier

 

Also known as a 'didymium' filter, this is used to enhance red, orange and brown subjects to give more colour saturation and contrast, whilst having very little effect on other colours. It can be used in many situations such as architecture where certain building features need emphasising, or for landscapes to enhance foliage and rocky features.

 

Sepia

 

These two filters give a nostalgic effect to otherwise ordinary colour photographs. Sepia tones are produced across the whole image, as if taken many years ago in Black & White, having then discoloured with age. Sepia B has a stronger effect than Sepia A.

 

Pop filter set

 

Available in a set of three colour filters: blue, green and red. Used individually or in combination, extremely original colour effects can be obtained. Also great for multi-exposure creativity.

 

Fantasy colour setThis set of three strongly coloured filters in Moonlight Blue, Vivid Pink and Deep Mauve can be used to give a single colour effect over the whole of a picture. Used in daylight, the Moonlight Blue filter gives the effect of a nigh time moonlit scene whilst the other two filters allow graphic and unusual images to be produced for special impact.

 

Half colour set

 

Made by sandwiching a gelatin filter between two optical glass plates. Similar to DUAL-COLOR except one-half is clear. Set in a rotating frame for added effectiveness. Color options: Pink, Yellow, Orange, Red, Emerald, Green, Brown, Blue, Violet, Light Gray, Dark Gray.

 

Gradual Colour

 

Acrylic filters similar to half-colour, except that colour density gradually decreases near the centre of the filter allowing emphasis of foregrounds or backgrounds. Mounted in a rotating frame.7 colours are available: Pink, Yellow, Emerald, Tobacco, Blue, Mauve, Gray. Their colour gradually fades out so the boundary between the coloured and transparent sections will not become apparent even with the lens aperture stopped down.

 

Dual Colour

 

Two colourless glass plates with etched parallel lines on each surface and set in independent rotating frames. By rotating these frames, the effect can be varied to produce any desired expression for any highly reflective scene.

 

Gradual Colour

 

Available in three types: O/G(orange/green), Y/P (yellow/purple) and R/B (red/blue). Made by sandwiching gelatin filters between two pieces of optical glass, DUAL-COLOR is available in a variety of two-colour combinations. Contrasting foreground and background, land and sea, are only a few of the fantastic possibilities.

 

PL Colour

 

Available in four types: B(blue), Y(yellow), O(orange) and R(red). A combination of grey and coloured polarizing filters. Any colour from grey to the full colour of the filter can be obtained by rotating the filter frame. Vario PL ColourAvailable in five types: Y/B, Y/G, Y/R, R/B, and R/G. This filter is a combination of one grey polarizing filter and two coloured polarizing filters. The colour can be varied by rotating the filter frames. Many colour possibilities help create new emotional effects never seen before.

 

Soft-Diffused Effects.

 

Centre spot

 

A close-up lens with a hole in the center. The periphery of the picture is rendered a delicate, soft focus effect while the central image is sharply focused.

 

Soft spot

 

Both have a clear center spot which makes the central image stand out clearly. SAND SCREEN has a smoky appearance while SOFT SCREEN has an irregularly uneven surface. With SOFT-SPOT, the size of the clear part in the center of the picture varies depending on the lens and aperture used.

 

Misty spot

 

Available in four types: Gradual, Breeze, Windmill and Halo. They have a sharp central image with a pleasant blurring of the outer field. With Gradual, blurring that appears to emanate from the center. Breeze has an unidirectional streaky blurring of background. With Windmill, blurring that appears to swirl about the center, and with Holo, blur that appears to radiate from a single point at the edge of the field.

 

Rainbow spot

 

Made of glass, and provided with rotating frames. 1,270 ultra-fine parallel grooves per inch pick up and diffract each tiny point of light into a rainbow of colour.

 

Fog filter

 

Lightly veils the entire picture in white. Available in a set of two: FOG(A) and FOG(B). FOG(B) has a stronger effect than FOG(A). Both can be used together to produce an effect similar to dense fog. The effect can be varied by changing the aperture of the lens, but stopping down too far will reduce the effect.

 

Diffuser, Duto filter

 

Both are diffusion type filters but DIFFUSER gives a soft-focus effect due to its irregularly uneven surface while DUTO has fine concentric lines etched on its surface. The centre of the picture is usually sharp with DUTO but DIFFUSER gives an overall soft-focus effect. Both are particularly effective in portraiture and commercial photography.

 

Softener (A, B) filter 

 

(A) A filter randomly arranging minute lens shaped like drops of water on the surface of an acrylic board. Scatters the light and results in a soft focus. (B) Creates a picture with a clear focus and a soft gradation, and this effect is especially evident with an object with a point light source. Colour reproduction is easy, and there is no need for exposure adjustment.

 

Spectral cross

 

An overall soft-focus effect is obtained for portraits, etc., outdoors with direct lighting, while backlighting or point light sources at night create heightened cross effects.

 

The effect is somewhat softer than with cross screen and diffraction of the light produces a slight amount of flare. A filter made by sandwiching black gauze-like fibre between two pieces of colourless, transparent optical glass in a rotating frame. Producing both soft focus and cross effects.

 

Other Effects.

 

Split field

 

One-half of a close-up lens with the other half open. One-half of the picture receives a close-up effect while the other half is normal. Both very close and far subjects can be in focus at the same time. Or one-half of the picture can be out of focus for special effects.

 

Dual image

 

 

One half of dual-image is transparent while the other is black. Used for producing special effects by taking double exposures. For example, the same person can be photographed on both sides of the same picture. When taking such photographs with this filter, refer to the instruction manual of your camera, and the use of tripod is recommended.

 

Cross section

 

Cross Screen adds a dramatic four-cross flare to very bright areas, giving a soft-focus effect. Perfect for photographs of ladies wearing jewellery or other objects with strong reflections. STAR-SIX (six-pointed light flares) and STAR-EIGHT (eight-pointed light flares) can also be used for a variety of effects.

 

Variocross

 

Two colourless glass plates with etched parallel lines on each surface and set in independent rotating frames. By rotating these frames, the effect can be varied to produce any desired expression for any highly reflective scene.

 

NDx2, x4, x8

 

In conditions of extreme light intensity, such as sunshine on snowy mountains or on the beach, or when using a camcorder, ND (Neutral Density) filters are recommended as essential. Neutral Density filters are often ignored by photographers, but they have several uses and offer the possibility to achieve otherwise unachievable results. ND filters appear grey and reduce the amount of light reaching the film, they have no effect on colour balance. They have four main uses: To enable slow shutter speeds to be used, especially with fast films, to record movement in subjects such as waterfalls, clouds, cars, seas etc. To decrease depth of field by allowing wider apertures to be used, which helps separate subjects from their background. To decrease the effective ISO of highspeed film (ie: above ISO400) and allow it to be used outdoors in blight situations. To allow cine and video cameras (which have fixed shutter speeds) to film subjects such as snow, sand or other bright scenes which would normally cause over-exposure.

 

Center ND (x2)

 

This filter combines two curved optics, one of which is neutral density and the other is clear. This gives the effect of a gradual fade towards the edges, with a difference of 1 stop from centre to edge. It is used primarily to remove vignetting which occurs with Large Format cameras when using wide-angle lenses, to give an evenly illuminated shot.

 

ND x 400

 

Photographing solar eclipses and ultra-bright light sources can be extremely dangerous. This filter reduces light values by 9 stops to less than 1/500th of its original intensity and allows safe photography. It can also be used to achieve super slow shutter speeds in daylight to render moving subjects invisible.

 

Half ND x 4

 

 

One half of this filter is NDx4 Neutral Density and the other half is clear, with a soft boundary between the two. It is used to control bright/dark contrast, by reducing half the shot by 2 stops. Particularly useful in landscape photography, the rotating mount allows bright skies to be easily controlled for dramatic effect.

 

Multivision

 

Available in five types: 3PF, 3F, 5F, 6F, and 6PF. Made of optical glass precisely cut into a variety of facets, MULTIVISION helps create exotic, fantastic compositions of colour patterns and combinations. The affect is strongest with a relatively dark background and at larger apertures. The multi-images appear closer together with wide-angle lenses and farther apart with telephoto lenses.

 

 

 

Close up

 

Available in +1, +2, +3 and +4 diopters for close-up photography. Depth-of-field is shallow so use as small an aperture as possible, CLOSE-UPs offer a world of new creativity.

 

Macro Close up

 

A lens of 2-element, 2-group construction and a +10 diopter rating. Resolution is outstanding and focusing is possible at 10cm for super close-ups of insects, flowers and other small objects. The magnification is about 1:2 with a 50mm standard lens (35mm camera), roughly equivalents to a 100mm telephoto lens. The lens should be stopped down as much as possible to get maximum depth-of-field.

 

Pol -Fader

 

A combination of two grey polarizing filters set in independently rotating frames. Rotating the frames varies the amount of light passed. Useful with exceptionally strong light sources, such as in solar photography, scientific applications, etc. Useful with movie cameras for fadeouts.

 

Infrared

 

Used for photography with infrared films. lnfrared film is also sensitive to ultraviolet rays and the shorter wavelengths of the visible spectrum so it is necessary to filter out all but the infrared rays. R72 passes only infrared rays above 720nm; RM90 passes only that above 900nm. Often used in crime detection, medical photography, detection of distribution of vegetation, etc. In ordinary photography with infrared film or infrared color film, the Y(K2), O(G), R(25A) and other filters can also be used to change the contrast or color effect.

 

 

 

 

 

 

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