Podrobné informace
ND (neutral density - neutral grey) filter helps to redukce the light of all of the wavelengths (colors). While using ND filter, the photographer can extend the exposure time and change the size of the shutter according to his priorities, which allows him to have the length of the exposure under control even under extreme circumstances (sea, mountains, snow). Anyway, cheap ND filters don´t reduce the intensity of the light of all of the wavelengths regularly, which can cause color defects on the final picture.
Among the ordinary ND filters which contain a single glass with a given factor of darkening, you can also use so called variable filters; the construction of the variable filters is constituted by two polarizing filters that are turned opposite each other. The intensity of the effect can be set up by mutual setting of the variable filters to the specified extent - this can be done thanks to the possibility to rotate the moving part of the filter. The intensity of the exploitable darkening of the filter is changing together with the lens focal point. As the focal point´s length of the lens increases, the intesity of the exploitable darkening is increasing as well (see the table below). This filter can be used for landscape photography, as well as for portrait photography. A lot of film makers can´t do without this filter.
Variable ND VFFOTO filters marked like as PREMIUM SERIES are developed, designed and completed in the Czech Republic. The components are being produced in China.
Not only that they are equipped with 14 antireflective layers (7 on each side) but also they contain new 3+3 nanolayers with the most developed functions: improved resistance to scratching, water-resistance, improved resistance to grease, easier cleaning.
These filters are being produced using first-rate polarizing foil of the Japanese company Nitto and the first-rate optical glass Schott B270 (more information about this glass can be found here).
ND filters of this series are designated especially for digital cameras, but they can be also used for classical cine film reflex cameras.
variable ND filter 2-32x VFFOTO PS 67 mm - specifications
| |
|
| used glass |
optical glass Schott B270 |
| polarizing foil is sealed up all over its surface |
yes |
| polarizing foil is sealed up on the sides |
yes |
| black frame of the glass |
yes |
| color shift |
relatively small, around 500 K (it can be changing together with the intesity of the darkening of the filter) |
| thickness of the all glasses (4) |
2.5 mm +/- 0.2 mm |
| height of the frame after screwing |
5.9 mm - slim |
| material of the frame |
aluminium alloy |
| number of antireflective layers |
14 (7+7) |
| nanolayers |
yes |
| weight of the filter |
33 g |
| use of ordinary lens cap |
yes |
| rear thread |
M 67 x 0.75 mm |
| frontal thread |
yes |
| time extension of |
2-5 EV (is valid for focal length about 35 mm) |
| light transmission |
50-3.125% (is valid for focal length about 35 mm) |
| HD quality |
yes |
What can the variable ND filter 2-32x VFFOTO do - interior:
Why you should decide for ND variable filter 2-32x VFFOTO PS:
1. 14 (7+7) antireflective layers of high quality = minimization of the unwanted reflections,
2. closing external treatment of the filtr using nanolayers = resistance against water, scratching and impurities, easy cleaning, these layers improve the mechanical and physical qualities of the used glass,
3. original optical glass Schott B270 of high quality = it preserves even the finest details of the contours without having an impact on sharpness,
4. the polarizing foil Nitto is sealed up all over the surface, as well as on the sides = protection of the polarizing foil against moisture, unfavorable influences, the perfect tightening of the foil leads to a great quality of the final picture,
5. for the wide extent of the focal points 17-800 mm (recalculated on full frame) = universal use, suitable for wide angle lenses as well as for telephoto lenses,
6. a special hydrophobic treatment causes that the water drops are not spilling over but they are formings ball = the drops slips from surface by itself or in can be blowed out using the blowing ballon, thus it prevents the picture from damage (splodge) that can be caused by one drop of water,
7. the glass filter doesn´t create static electricity = it doesn´t magnetize dust, in contrary to the plastic (resin) filters,
8. excellent price-quality ratio = a satisfied customer, who will turn back,
9. precisely manufactured = reliability,
10. relatively small color shift = these filters can be successfully used in black and white photograph but also in colourful pictures,
11. low design frame = it provides no vignetting, it can be used with the ordinary lens cap,
12. a possibility to change the glass in case of its damage,
13. 10 years guarantee - the final quality check of each piece takes place in the Czech Republic.
Dependency of the exploitable intensity of the ND filter VFFOTO on the focal point of the used lens
| lens focus (recalculated on full frame) |
darkening |
light transmission (%) |
| 16 mm |
16x |
6.250 |
| 35 mm or more |
32x |
3.125 |
VFFOTO´s recommendation:
This filter can be recommended even for the best lenses with the focal length of 17-800 mm (recalculated on full frame) from companies such as Canon, Nikon, Carl-Zeiss, Leica, Hasselblad, Olympus, Pentax, Fuji, Sony etc.
Evaluation of the pictures in atelier - shift of the colors (the temperature of the colors is set up in both pictures for 3600 K):
focus 100 mm (FF), light transmission 50% (ND 2x - minimal possible darkening)
focus 100 mm (FF), light transmission 3.125% (ND 32x - maximal possible darkening)
Evaluation of the pictures details in atelier (100% magnification without sharpening):
focus 100 mm (FF), light transmission 50% (ND 2x - minimal possible darkening)
focus 100 mm (FF), light transmission 3.125% (ND 32x - maximal possible darkening)
Evaluation of the pictures in exterior - shift of the colors (the temperature of the colors is set up in both pictures for 5000 K):
focus 24 mm (FF), ND 2x - light trasmission 50%
Evaluation of the pictures in exterior - shift of the colors (the temperature of the colors is set up in both pictures for 5000 K):
focus 24 mm (FF), ND 32x - light transmission 3.125%
in case you using a very strong ND effect (not suitable for this focal length) there will be a non-uniform darkening of the picture
Evaluation of the pictures in exterior - shift of the colors (the temperature of the colors is set up in both pictures for 5000 K):
focus 42 mm (FF), ND 2x - minimal possible darkening (left)/ND 32x - maximal possible darkening (right)
Evaluation of the pictures details in exterior (100% magnification without sharpening):
focus 200 mm (FF)
The video was shoot by Petr Klempa (http://petrklempa.cz) using VFFOTO variable ND filter 2-32x:
