Think of a multi-layer coating when buying filters. This one is especially important as filters with no or simple coating can lead to unwanted reflections, light loss and finally to a deterioration of the picture quality. The reproduction quality of your high-grade lens remains then unused.

At the time of analogue photography it was hard to imagine photography without filters as there was no other possibility of influencing photos. Filters were e.g. used for simple colour correction and special effects. This did not change when the digital photography was introduced.
Nowadays, a computer offers the possibility of correcting, touching up and modifying nearly all photos afterwards. Nevertheless, photographic laws cannot be neglected. Considering specific circumstances when taking photos and using the appropriate filter is better and more professional. The consequence: you save more time and achieve an optimum result.

Advantage of today: The effect of a filter can directly be controlled on the display. This creates space for a lot of creativity. Just try it.

Glass surfaces have the fundamental property of reflecting light. This effect is naturally unwanted as far as lenses and filters are concerned as the complete incident light should get to the photo sensor. A mirrored pair of sunglasses profits e.g. from this fact! A large part of the light is reflected, less light reaches the eye, the image gets darker.

A light loss of approx. 4 to 5 % is caused on any uncoated glass surface because of partial reflection (on both surfaces of uncoated filters 8 to 10 % altogether). This is due to the different refractive power of air and glass which unavoidably leads to a reduction of the lens speed.

A coating is applied to the glass surfaces in order to avoid or reduce light loss with lenses and filters. This one consists of one or several different layers (the more, the better). The coating has positive effects on the transition of light from the air into the filter glass and vice versa. It eliminates thus the light loss almost completely.

If a filter is put in front of wide-angle lenses, this one can already jut out into the picture angle. This becomes apparent by dark picture corners - the vignetting. With slim mounts of slim filters, this negative effect cannot occur.