Since I’ve started using social media the question I get asked the most is “What filters are you using?”, or more specifically “What kind of Neutral Density Filters are you using?”. So here is some information you could find useful.
Graduated Neutral Density (GND) filters are resin filters of square or rectangle shapes, which have a dark neutral density half, decreasing light transmission, and a clear half. The transition in between the two sections can be either “hard” (abrupt) or “soft” (progressive), and the strength of the neutral density section can vary from 1 to 4 stops.
The filters require a filter holder, which will be attached to the front of your lens with an adaptor ring. A filter holder can hold several filters/slides at once.
Credit: Lee filters, see Leefilters’ website, links below.
GNDs are traditionally used to control the light in scenes with a bright area (the sky), on which you apply the neutral density section of the filter, and a dark area (foreground, rocks, mountains, etc.) on which you apply the clear section of the filter. The key is to use the right strength of neutral density, and to place the transition appropriately.
Equivalent systems to the GNDs were described in publications from the beginning of the 20th century, but the GNDs like we know them went mainstream with the work of American landscape photographer Galen Rowell (Singh-Ray).
In the digital world there are various techniques using multiple exposures to re-create “dynamic” images, but you want to get properly exposed photos straight from the camera. Every landscape photographer are using them, they are a “must have”.
What to choose?
From my experience Lee and Singh Ray are probably the two best brands to buy from. Their handmade filters are more expensive but their quality is remarkable. I tried Cokin, Hi-Tech and others, and was often disappointed by the lack of consistency with different light settings, not to mention the colour cast you get with some of them.
Choosing the right strength and transition (hard or soft) will depend on your type of photography. If you shoot mostly seascapes, prefer hard edge filters, if you shoot mostly landscapes where the horizon isn’t straight (hills, mountains, etc.), prefer the more polyvalent soft edges. For sunrise and sunset photos where you are looking straight at the sun, 3 stops (0,9) is what you need, you might even be required to stack two GNDs to control the light. For landscapes where you are looking away from the light, some cityscapes and travel photos, a 1 or 2 stops soft edge GND can come handy (look at the Lee filters gallery to see when and how to use some of their filters).
Finally if you can afford 2 or 3 filters and shoot a lot of sunrises and sunsets, I would highly recommend using a Reverse GND (Singh-Ray). Those have the maximum density in the middle (the horizon), and get lighter towards the edges. Imagine a sunset with a clear sky and a few clouds, if you use a classic GND the top of your photo is likely to be a bit dark, the reverse grad will help you avoid this.
(1) GNDs by Lee Filters:http://www.leefilters.com/
(2) Filter holder by Lee:http://www.leefilters.com/
(3) GNDs and Reverse GNDs by Singh-Ray:http://www.singh-ray.com/
(4) Colour landscape photos from Joe Cornish using a variety of Lee Filters:http://www.leefilters.com/
(5) Metering and applying filters, pdf available on the Lee Filters website (click on Metering Techniques): http://www.leefilters.com/
(6) The fantastic Singh-Ray Blog: http://