About Filter On Lens

Filter is an additional accessory equipment on your particular lens on a DSLR camera. Although without a camera filter was already able to get a good photograph, but sometimes the use of filters are necessary. There are different types of filters available in the market for different purposes, ranging from a mere ward to filter ultraviolet light special needs such as infra red. Buying a filters also need to know the size of the diameter of the filter because the filter diameter options in the market varies, so does the optical quality (standard, multi-coated, super).

Camera lens filter is most frequently used by the photographers both amateur and professional, among others, kind of: Ultra Violet (UV), Polarize (either linear or circular), Gradual Neutral Density (GND), warming / cooling and colored filters. Each of these filters has the functionality and usabilitysuch as:

Tipe Filter	Main Functions	Usually used in
Linear & Circular Polarizers	reduce Glare adding Saturation	Sky / water Landscape Photography
Neutral Density (ND)	Adding Exposure time	Waterfalls, rivers, at a time when the bright light
Graduated Neutral Density (GND)	Gradient controls the force of light reduce Vignetting	Landscape with dramatic effect
UV / Haze	Add brightness in photos Provide protection to the front lens	Everything
Warming / Cooling	Changing the White Balance	Landscapes, underwater photography, light effects

Here's the translation of the filters and their functions and the results generated image

Linear & Circular Polarizing (LPL / CPL)

Polarizing filters (polarizer) is widely used by the lovers of the natural landscape or scenery. Due to the nature of this filter makes the amount of light that happens to be a reflection of diminishing returns, as well as on the surface of the water, glass, sky and so forth. This filter is composed of two elements, one element is attached fix and one can be rotated. We need to rotate the CPL filter element to get the best effect. CPL filter lens can not be mounted on the front element rotates during focus, like most of the kit lens. The most prominent effects were seen from the use of this filter is the color of the sky that 'the invisible dark blue' when compared with no use of this filter.

The resulting image

Linear vs Circular

The main difference between the linear polarizer (LPL) and circular polarizer (CPL) is the use of automatic metering and autofocus on your SLR camera. Where CPL filter still allows proper functioning of automatic metering and autofocus directly from the camera as well as the failure to introduce the filter. While at LPL, besides the price is relatively more expensive than his CPL version, but the autofocus and metering system uses Through The Lens (TTL) can not be used when LPL filter mounted on your lens. There is one that allows the forego metering and autofocus, but that is rarely desirable by anyone.

Filter Neutral Density (ND)

main of Neutral Density (ND) filter is to reduce the amount of light that will enter into the sensor / your movie. With the decreasing amount of light available, the exposure time can be made longer than its standard settings. Some common situations using ND filters are:

1. Make the subject blur / not visible on the car (people) who are running
2. The movement of water ripples river / coastal increasingly smooth as silk
3. To get the Deep of field in bright lighting (contrast), especially in the daytime

Each of these manufacturers has a ND filter definition (naming) and scale filters they produce, the following is a simple table for some ND filters are the leading manufacturers following its effect:

Amount of light reduction		Hoya, B+W and Cokin	Lee, Tiffen	Leica
f-stops	Fraction
1	1/2	ND2, ND2X	0.3 ND	1X
2	1/4	ND4, ND4X	0.6 ND	4X
3	1/8	ND8, ND8X	0.9 ND	8X
4	1/16	ND16, ND16X	1.2 ND	16X
5	1/32	ND32, ND32X	1.5 ND	32X
6	1/64	ND64, ND64X	1.8 ND	64X

The average photographer only took 1 or 2 ND filter only by a margin of 1 to 2 f-stop. Because the larger the f-stop that is going to make the longer exposure even in broad daylight conditions though.

The resulting image

Graduated Neutral Density (GND)

Almost the same as ND filters, ND gradual filter reduces light intensity, but not entirely, but only half of it. This became a favorite filter filters landscape lovers who often photographed a high contrast areas, such as half area of ​​the photo is the sky and half the field again is earth.

Unlike the human eye, the sensor on the camera has a limited dynamic range of outreach. The camera will be difficult to capture all the light intensity range of dark to light. Though the sky element has a very light exposure (commonly called highlights) and the camera metering will be affected by the brightness of the sky that makes the area so dark shadow.

When installed properly, gradual ND filters can reduce the intensity of the sky in the area while not change anything in the rest of the field. This will cause the light entering the camera so more evenly and avoid areas of over and under. When to have a ND filter is considered expensive, we can get around this problem with HDR photography (take 3 photos at different exposures and then merged the computer).

This filter is used to 'limit' the amount of light coming into the sensor / movies gradation (separation) that follow the patern (patterns) specific. This filter is also sometimes called the 'split filter'. The use of this filter commonly used in landscape photography, especially for shooting with the lighting system made ​​gradation from light to dark, such as: sunset (sunset) / sunrise (sunrise).

Position 'blend' of gradations fitting that can produce a dramatic effect on a photograph. There are many different types of shades that blend can be found in the market today, such as: soft edge, hard edge and radial edge. Where each 'edge' has advantages and disadvantages.

The resulting image

UltraViolet (UV) / Haze

The use of filters UV / Haze today is more due to protect the front of the lens that are not easily scratched or exposed to dirt. Due to the nature of ultraviolet rays (UV) which is not visible to the naked eye, then the filter is usually called the 'clear filter'. If the filter is used on cameras that use film, it will reduce the effects of haze (haze) and increase the contrast of color due to reduced UV colors. While the digital camera that uses sensors, UV filter is 'almost' had no effect at all, because of the sensitivity of increasingly sophisticated sensors that can be reduced by the UV rays of the existing system on a digital sensor.

some of common UV filter can cause a decrease in the quality of the resulting image, and cause flare effects to light. But for a UV filter which has multi-coated it has been minimized so that 'ordinary eyes' as if it did not see a significant difference to the end result.
Bonus function of the UV filter is to raise the resale price of the lens. Due to the condition of the lens is 'protected' from scratches / dirt, so it is like a second hand lens new lens.

The resulting image