Sensors and Filters “Reality” Eye + Brain Eye + Brain Image (Perceived) Image (Perceived) Sensor Image (Memory) Image (Memory) Display Eye Image (Perceived) Naked Eye Capture Show Filters

Film “Reality” Negative Print Negatives “Reality” Slides

Digital “Reality” CCD File Monitor Print Projector

Filtering with film photography “Reality” Optical filter Lenses Film

Filtering with digital photography “Reality” Optical filter Lenses CCD Photo Shop File

Film Speed

Sensor Speed

The colour wheel

Filters for B&W We use filters to enhance certain features when taking a photo in b&w.

Red Filter Red filters produce a very strong effect and greatly increase contrast. They're often considered too "harsh" for most types of photography, but can be used to produce striking creative effects. In landscape photography, a red filter will turn a blue sky almost black and make clouds really stand out, giving the scene a dramatic feel. They're also excellent for increasing visibility in haze and fog. When shooting plants they help increase definition between flowers and foliage. This is particularly useful when shooting red flowers, as they have a similar tone to the surrounding leaves.

Orange Filters Orange filters sit between red and yellow filters, giving a nice balance of each one's properties. This makes them a popular general purpose filter. In portrait photography, an orange filter reduces the appearance of freckles and blemishes, giving the skin a healthy, smooth look. When photographing buildings and cityscapes, they give bricks a pleasing tone, and increase contrast between different materials to add depth and texture to the image. Similarly to red filters, they can be used to reduce the appearance of fog and haze, and to darken skies and emphasise clouds.

Yellow Filters Yellow filters produce the most subtle effect of the 5 coloured filters. In some cases the difference is barely noticeable, but it can help to lift a photo just enough. They're a popular choice for beginners as they can be used in virtually any type of photography. When snapping landscapes a yellow filter darkens the sky slightly, helping to balance its exposure against the darker ground. They also bring out clouds nicely, resulting in more interesting skies. In portrait photography, they produce warm, natural, pleasing flesh tones, like an orange filter but less intense.

Green Filter A green filter is mainly used for photographing plants as it helps separate the green foliage from the brightly-coloured flowers and buds. They can also be used in landscape photography to boost the appearance of grass and trees, but they also lighten the sky so you need to be careful not to lose detail there.

Blue Filter Blue filters are rarely used for black and white photography. They darken most colours and reduce contrast across an image. When used correctly, this reduced contrast can be useful for giving a shot a calm, soothing atmosphere. A blue filter also increases the appearance of haze and mist, making it handy for enhancing the mood of an early-morning scene.

Filters for colour We can also use filters in colour photography to alter part or all the chromatic content of the image

UV Filters They do not change a digital image. But they are cheaper than your lens to replace !

Neutral Density Filters Uniformly reduce the amount of light reaching the camera's sensor. This is useful when a sufficiently long exposure time is not otherwise attainable within a given range of possible apertures (at the lowest ISO setting). Situations where ND filters are particularly useful include: Smoothing water movement in waterfalls, rivers, oceans, etc. Achieving a shallower depth of field in very bright light Reducing diffraction (which reduces sharpness) by enabling a larger aperture Making moving objects less apparent or not visible (such as people or cars) Introducing blur to convey motion with moving subjects

Gradual Neutral Density Filters Soft Edge Hard Edge Radial Blend

Polarizers