Getting just the right amount of a good thing

If you’ve ever admired those beautiful fluffy whitewaterfall photos, or creamy streams flowing past those polished boulders, you’veprobably been looking at a photo where a neutral density (ND) filter has beenused.

To achieve that soft texture in water, you need to leaveyour shutter open for a longer period of time, allowing the sensor to capturewhat then becomes a soft flow of water, versus a sharp rendition of the waterat a given moment in time.  A photo takenat 1/250 of a second in bright light will never get that creamy look.  However, if you could reduce the amount oflight hitting your camera’s sensor, and take the same shot at 1/15 or 1/10 of asecond, then a much smoother version of the water is quite apparent.  A neutral density filter is what makes themagic happen.

Without changing the color of your photo, a neutral densityfilter blocks much of the light coming through it, creating the need for extraexposure and hence, a slower shutter speed. Depending on the brightness of thedaylight, you may need a slight exposure increase and would therefore use  a 2 stop filter, or you might need an extra,extra deep dose of filtration, in which case you would use an 8 stop filter.There are also various other steps available as well.

If that sounds like a lot of filters to carry…you are right.Tiffen heard the photographer’s plea and created an answer to prevent needing aboat-load of filters in your bag…the Tiffen Variable ND filter.

The TiffenVariable ND filter operates on the same principle as a Circular Polarizer –rotate until you reach your desired effect and shoot. It allows you to havecontinuous control over the amount of light coming through your lens in anapproximate range of 2 (ND 0.6) to 8 (ND 2.4) stops – while maintaining theintegrity of your image. Note: The evenly spaced indexing marks between MIN andMAX do not represent calibrated stops. They are for reference only, to be usedas a density bench-mark to return to a previous setting.

Having tested the filter in a range of situations, I wasalways able to find a setting that worked. Having that complete range ofadjustability is quite liberating. If you want to only pack one filter, this isthe one to consider.

Presently, the filter is available in one size only – 77mm.  If your lens is smaller, you’ll want to alsopurchase a step-up ring to handle the transition. Various rings are availablefor most of the popular lens diameters.  According to their website,additional size filters are coming soon.