The Filter System
My creative process drives me to get everything right in-camera rather than spend hours on a computer after a shoot, so to achieve this, I use a variety of neutral density filters and a polariser from Lee's 100mm filter system.
Good quality neutral density filters reduce light levels without affecting colour balance and it is clear to see how strong an effect a filter will have simply by looking at it - the stronger the effect the darker the filter. Each filter in the Lee system also carries a code to indicate how many stops of light the filter will reduce exposure by. Polarising filters, like their ND counterparts, appear grey in colour but tend to quite difficult to see through without holding them up to the light. Again, good quality polarising filters reduce light levels without affecting colour balance.
Neutral Density Filters
There are two commonly used types of neutral density (ND) filter:
- ND Standard - Where the grey area covers the whole filter.
- ND Graduate - Where the grey area covers just a portion of the filter. Graduated filters are also manufactured to provide one of four different gradations - Soft, Medium, Hard and Very Hard. These terms indicate how gradual the transition from grey to clear is, so for example, a Soft grad will have a much more gradual transition than that of a Hard grad.
There are two types of polarising filter and it is important to buy the right type for your camera:
- Linear - Used on cameras that do not have sophisticated autofocus or metering systems (e.g. manual focus film cameras).
- Circular - Can be used in place of a linear filter but is normally used on modern automated digital cameras that seem to be sprouting ever more complicated additions aimed at improving their usability or, conversely, resting control of image creation from the photographer.
- 105mm Circular Polariser - Reduces the effect of reflections, reduces exposure by up to two stops and enhances, for example, white clouds against a clear blue sky. This filter requires a special mounting ring to be fitted to the front of the filter holder.
- 0.3 - Reduces overall exposure by one stop
- 0.6 - Reduces overall exposure by two stops
- 0.9 - Reduces overall exposure by three stops
- 0.3 Hard - Reduces exposure by one stop over the chosen portion of the frame
- 0.6 Hard - Reduces exposure by two stops over the chosen portion of the frame
- 0.9 Hard - Reduces exposure by three stops over the chosen portion of the frame