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Photography filters


Photographic filters are among the most essential equipment in a photographer's bag.
With the use of filters alone you can make your photographs look more different and interesting. It is obvious that digital photography, along with the rich in filters image editing programs, have made most of the conventional filters useless, thus we will refer to filers that can be useful in the modern digital era photography, as well as in classic black & white and color films.

Photographic filters exist in different forms and shapes. The two most dominant categories are

a) The autonomous round crystal filters with a metal frame screwing in the front end of the lens, and their diameter should match that of the lens. These may vary from 38mm to 77mm, with most common those of the 49mm and the 52mm,
b) The square plastic or crystal filters that you put on a carrier already adjusted on the lens. Well known filters of this category are the ones from KODAK and the filter system of COKIN.
Filters, as an added optical element on a very well designed combination of optical elements that the lens is, it is mandatory that they should well designed, with multi coated layers and from fine optical crystals, otherwise they cut down from the quality of the lens.
The most qualitative filters are those of German W+B (but they are very expensive) and the Japanese HOYA that come in more reasonable prices. A cheaper but reliable solution is the filters of MARUMI.

photography filters

Lens- protective Filters
The common filter for this use is a UV filter that does not produce any chromatic alteration. However it protects the lens from dust, scratches and falls. It has another usefulness; it cuts the not needed ultraviolet radiation that the photographic materials are also sensitive to.
But this is achieved by any crystal and specifically by the crystals of the modern lenses with the multiple coatings. The same anti-UV protection have also all the kinds of digital sensors.

Another filter that is used for the same reasons with the UV is the skylight filter or 1A that however is not completely neutral but it has a lightly pink nuance. In the black & white it does not have any effect, but in colour it cuts a little of the blue radiation, and for this it is usually used in big altitudes and in clouded over rainy days where the blue radiation is in excess. Of course for a better correction in such situations other more suitable filters exist, like the 81A or the 81c.

ND. Filters of neutral density.
The filters of neutral density are filters graded in grey tones and they make only thing; they cut the light that will pass via the lens in the camera. They usually exist in densities with differences of one stop, and the 2 cuts 1 stop the 4 cuts 2 etc. Or graded with their real density (D) value (ex. 0.3, 0.6 etc). The filters of neutral density are useful in situations that we need openly diaphragms and we have a lot of light (ex. when we want small depth of field) or when we need slow speeds (ex. Panning technique). There are also the degrade filters of neutral density that are useful when we have two departments of picture with big lightning differences.

Polarising filters.
They are the most expensive usually filters but also the filters that no program of picture editing cannot make what they offer. The polarising filter is constituted by two crystals of which one is able to turn, thus we can select the result that it will have in our picture. Its basic applications are the control of reflections and the saturation of colours and it exists in two types, linear polarizer και circular. The second is essential in autofocus cameras.

Close up Filters.
The close up filters are the cheap solution when we want to photograph from very near, because they increase the magnifying faculty of our lens and substitute the macro lenses. It is unnecessary to say that their quality is low. They are graded in degrees of enlargement (+1, +2 +3, etc) and they are usually sold in sets of 3 or 4. Along with the rings of lens inversion, the extension tubes and Bellows , they are the elements that try to cheaply substitute a macro-lens (that usually has quality insuperable).

Filters of chromatic correction for the black & white photograph.
These filters are colourful and they help us in the control of tone of grey that will be attributed to the various colours in our photographs. Certain examples: an orange filter will attribute the sky as darker grey from that which it would record the film- as a result the clouds will distinguish in the picture, and a red filter would record the sky almost black and all red objects in our photographs much brighter from what they really are.

It may appear that the image-editing programs have made the photographic filters pass in disuse, but most of the times the result with the filters is better than any treatment, even with digital cameras , not to mention that nothing cannot replace a polarizer or neutral density filter.