Understanding Photography Filters

Photography filters are pieces of glass or resin that you use in front of your camera’s lens. They allow you to add a creative touch to your photographs depending on the type of filter you choose to use. Sometimes they are just a nice-to-have option, while other times they are a must. Filters were indispensable during the days of film, although I cannot vouch for that personally (no experience shooting film). With the advent of Adobe Photoshop and Digital Photography, the use of filters has taken a back seat. Digital processing techniques like HDR allow the photographer to get the same, if not better effect as when using a filter (Grad ND filter in this case). But there are times when you cannot get a particular effect by post processing. One such effect is a slow motion blur of flowing water, when shooting in relatively bright situations.

Filters come with a bit of controversy too – like the debate of whether it makes sense to put a cheap quality filter in front of expensive glass. I have seen local wedding photographers asking for the cheapest UV filter so that they can protect the front element of the lens. I don’t have a problem using filters, but I would trust only well known filter manufacturers like Hoya, HiTech, B+W etc.

Once upon a time, grad ND filters were the most important ones in a photographer’s bag. These are used to prevent the sky from blowing out while shooting a landscape scene with a lot of contrast. I personally have been using the technique of High Dynamic Range (HDR) to achieve the same results since a while now. You’ll find a lot of photographs on the internet which have been processed using this technique. Unfortunately, 95% of these HDR images are badly done and look artificial. This is primarily because the digital imaging tools used to create HDR images are not simple and the technique itself is not clear to many. These days I have started using Grad Neutral Density filters to avoid creating HDR images. I don’t think Grad ND filters will replace HDR imaging in my workflow, although the former ought to make life easier in places where setting up a tripod is not feasible. In the video below, you will see a few types of rectangluar Grad ND filters and how they can be used with lenses. But a word of caution – these filters are expensive and not available here in India. Also, if used incorrectly, they can cause vignetting and other bad things (like a busted wallet).

Circular Polariser filters are very popular, although I don’t use one myself. They don’t give the desired effect on my Canon 10-22 mm lens and I do most of my saturation boost in post processing. I am also a little vary of carrying too many fragile items in my bag. Another useful filter is the Neutral Density (ND) filter. These filters are used to decrease the shutterspeed when shooting in broad daylight, and can help creating a silky effect when shooting moving water. This is one effect that cannot be recreated easily in Photoshop. Hence, an ND filter is pretty important if you are into waterscapes and such.

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