Formatt graduated neutral density filters allow the photographer to adjust exposure without affecting colour balance. Exposure can be increased by 1, 2, 3 or 4 stops to suit individual situations.

It is often necessary or desirable to balance the light intensity of one part of a scene with another. This is particularly true in situations where you do not have complete control over the lighting, such as in bright and contrasty landscapes. Exposing for the foreground will produce a washed-out and overexposed sky, whilst exposing for the sky will leave the foreground dark and underexposed. This filter allows cloud detail in the image to be correctly exposed.

Determining which graduated neutral density filter gives ideal results for a given lighting situation requires knowledge, experience and a collection of such filters. Choose the filter strength that adjusts the lighting to remain within the exposure latitude (greatest difference between light/dark values) that still shows detail in the digital or film medium being used.

Generally, the 2-stop value (ND 0.6 - the clear part of the filter allows 4 times more light through than the darkest part) effectively compensates for average bright sky versus foreground situations, and the soft transition is more often applicable to a scene than the hard transition.

Formatt, a company with three generations of experience in manufacturing professional filters, produces each filter to the highest technical standards. The finest materials, combined with cutting-edge production technology, have resulted in a level of optical excellence unmatched elsewhere.

Soft/hard indicates the degree of transition.

Note! A standard ND set comprises 0.3, 0.6, 0.9 and 1.2. This represents 1 to 4 stops of light reduction


Advantages

- All Formatt filters are manufactured using Schott Water White optical glass which is precision polished and ground to ensure absolute optical flatness and optimum performance

- Optically consistent from one filter to another


Neutral density filters have four main uses

- To enable the use of slow shutter speeds, particularly with high-speed films, to record movement in subjects such as waterfalls, clouds or cars
- To decrease depth of field by allowing the use of larger apertures, which helps separate subjects from their background
- To decrease the effective ISO speed of high-speed films (above 400 ISO) and allow them 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


Neutral density factors

- ND.3 (exposure adjustment = 1 stop, reduces ISO by 1/2)
- ND.6 (exposure adjustment = 2 stops, reduces ISO by 1/4)
- ND.9 (exposure adjustment = 3 stops, reduces ISO by 1/8)
- ND1.2 (exposure adjustment = 4 stops, reduces ISO by 1/16)


Formatt graduated filters are available in four types

- Soft edge - Half clear, half coloured with a gentle transition to full density. Generally used with wide-angle to medium lenses
- Hard edge - Half clear, half coloured with a defined less subtle transition. For use with long focal length lenses
- Sharp edge - Like hard edge but with a solid transition line for photographing building corners, sharp horizons or when a very pronounced transition is required
- Attenuator - The graduation line is right at the edge of the filter, so the colour change extends from top to bottom. Perfect for irregular objects and horizon lines