Gear
Filters
Neutral Density Graduated Filters
ND grads are a vital part of the landscape photographer’s armoury. Skies are often considerably brighter than the ground and without a filter, the shot will either have an overexposed sky or underexposed ground. ND grads are half grey and half clear. By positioning the grey part of the filter over the brightest part of the frame, a more balanced exposure is achievable.
I use Lee ND soft grads, which reduce exposure by either two or three stops without affecting colours. Lee filters are considered among the best and are placed in a holder system which allows the filter to be moved vertically and tilted as necessary to cover just the right part of the frame. This is a key advantage over screw-in ND grads, where the division between grey and clear can only be placed half-way down the frame.
There's a nice article at Luminous Landscape which explains how these filters work and how to use them.
Ten-Stop Neutral Density Filter
This is a fantastic filter from B&W. A ten-stop ND filter reduces the amount of light entering the lens by 210 or 1,024 times. This means a shot that would normally need a shutter speed of, say, 1/60 of second would require an exposure 1,024 times longer, or around 17 seconds. Using a smaller aperture can increase this still further, as can photographing in low light, which can extend exposure times to minutes.
The advantage of this is that you can introduce motion blur into pictures, smoothing out water and mist (or both, as in my shot along the Thames of the Royal Star & Garter Home on Richmond Hill) or creating cloud streaks, as in my shots of the Pagoda and Palm House at Kew Gardens.
Circular Polarizer
Polarizing filters are another staple of the landscape photographer's kit. They can darken the sky, producing a deeper and more satisfying blue, reduce reflections from water and make foliage appear less shiny. They also result in more saturated colours generally. My filter is from the excellent Rodenstock.
The effect of polarizers varies with the degree of angle to the sun. The greatest effect is achieved when the camera is at 90 degrees to the sun. This can cause problems with very wide lenses, because the angle to the sun will vary across the frame, causing uneven polarization. There's a useful article on polarizers on the Luminous Landscape website.