The 49mm Neutral Density (ND) 0.9 Filter from Heliopan has several uses and offers the possibility to achieve otherwise unachievable results. A ND filter appears gray and reduces the amount of light reaching either the digital sensor or film plane. The filter has no effect on color balance.
A neutral density filter permits you to capture images such as the rushing movement of a babbling brook or the swirling chaos of city traffic. Without the filter, your final image would simply be a static shot of water frozen in a moment's time. Since wider apertures are possible, your depth of field will also be minimized. This gives you an edge when shooting portraits since you will be able to achieve more separation between your foreground and background. An ND filter permits you to shoot your image under bright light conditions at the same aperture but at a slower shutter speed.
Heliopan Lichtfilter-Technik of Munich, Germany, has changed their black anodized brass filter rings on most Heliopan non-rotating filters to their improved "slim" mount. This slim mount is made of black anodized brass stock and has so little rim in front of the lens (5.4mm) that it will not vignette (darken the corners of the image) with lenses as short as 21mm.
The reputation of Schott glass is world renowned. The high production standards combined with a sturdy brass filter ring make filters made with Schott glass hard to beat. These filters have a "heft" to them that is impressive. They may feel heavier but the benefit is in the construction and results. Not only is the glass exceptional but so is the seal between the ring and glass. Schott glass used in the manufacture of this filter is legendary and synonymous with the highest standards of filter production.
- Heliopan has been a leader in the filter industry since 1949. They are known for their high quality and production standards. Their slim mounts facilitate using them with wider angle lenses. Heliopan offers most of their filters with either their standard hard coating or with their industry leading SH-PMC 16 layer multi-coating that transmits over 99.5% of the light striking it on to the image plane for the lowest flare and greatest color saturation
- Filters still retain front threads for a lens cap, a lens hood or even stacking a second filter
- The portion of the Heliopan slim filters that are in front of the lens have been reduced in thickness by 37% over the former mount
- Heliopan cuts, grinds, polishes and coats their filters with the same techniques and equipment as used for the finest German camera lenses
Neutral Density Filters Have Four Main Uses
- To enable slow shutter speeds to be used, especially with high speed ISOs, to record movement in subjects such as waterfalls, clouds, or cars
- To decrease depth of field by allowing wider apertures to be used, which helps separate subjects from their background
- To decrease the effective ISO of high speed film (above ISO 400) and allow it to be used outdoors in bright situations
- To allow cine and video cameras (which have fixed shutter speeds) to film subjects such as snow, sand or other bright scenes which could cause overexposure