Digital photography doesn’t require the use of colour adjustment filters in the same way that film photography does, but there are some camera filters such as a neutral density (plain and graduated) and a polarizer that should still find their way into every photographer’s camera bag.
In this tutorial we look at some of the biggest mistakes that photographers make when using camera filters and explain how to avoid them.
Mistakes with camera filters: 01 Poorly positioned graduation
Graduated filters come in a wide range of colours such as blue to augment skies and water and orange to boost sunrises and sunsets. Neutral or grey grad, however, is definitely used most often.
Rather than change a scene’s colour, neutral or grey filters are designed to darken part of it. They’re commonly used to balance the exposures of the bright sky and darker earth beneath it.
The key to using a graduated neutral density filter correctly is positioning the graduated section. Set it too low and you’ll end up with a dark horizon, while setting it too high will make the lower part of the sky very bright.
Slowly slide the filter up and down while keeping your eye to the viewfinder or LCD screen until you have it in the ideal position.
Mistakes with camera filters: 02 Obvious graduation
Graduated filters have either a hard or soft graduation. With hard-graduated filters, the change from clear to full density occurs quickly, while soft-graduated filters have a change that is more gradual.
Flat horizons without protrusions into the sky are ideal scenes for hard grads.
If, however, there is a building or tree in your shot that extends into the sky it will be quite evident that you’ve used a filter. The customary solution here is to use a soft grad, yet even this may be noticeable in some cases.
The better approach is to take at least two images of different exposures without a filter and combine them into one.
SEE MORE: How to shoot a daytime long exposure
Mistakes with camera filters: 03 Polariser with wide-angle lens
A polarising filter is designed to reduce reflections, boost contrast and darken blue skies. If the sun is at the right angle and the polarising filter is rotated to create maximum effect, the sky will appear almost black.
The effect of the polarising filter is determined by its position relative to the sun, meaning that shooting with very wide-angle lenses can give you a varying impact across the frame.
It’s therefore a good rule of thumb to steer clear of polarising filters when uses very wide-angle lenses.
Mistakes with camera filters: 04 Black cross visible with a variable ND filter
Variable neutral density filters are a practical choice because they let you determine how much the exposure is changed. You can therefore use just one filter in a span of lighting conditions and by simply rotating the filter you can set the degree of movement blur.
A variable ND filter consists of two polarising filters. The quantity of light that passes through them is reduced or increased according to how they’re rotated relative to one another.
You shouldn’t, then, use a variable ND at its maximum point.
SEE MORE: How to photograph waterfalls
Mistakes with camera filters: 05 Dirty filters
A clean filter is just as important as a clean lens, perhaps even more so. Since filters are used in front of the lens, dust, scratches and fingerprints can be more noticeable than they would be on a lens.
The AF system can also have trouble with these marks, resulting in soft images.
To avoid these issues, simply handle filters only by their edges and store them in a case when not in use. If you do find yourself with a dirty filter or you pick up a stray water droplet, just wipe it gently with a lens cloth.
Mistakes with camera filters: 06 Cheap ND grads
As their name suggests, neutral density filters are intended to be neutral and not pass on colour to your images. This may sound like a simply concept, but it can be difficult to achieve with some filters actually changing the image’s colour a bit.
If you’re using a plain ND, this change isn’t too big of an issue as you can easily offset the problem with a custom white balance in-camera, or post capture.
If a colour shift occurs with a graduated filter, however, the effect won’t be consistent across the image making it a much more complex problem. Using a high quality filter from a known supplier is definitely worth it, then.
Mistakes with camera filters: 07 Over-stacking or wrong-sized system
Especially if you’re using a wide-angle optic, you can run into problems with corner shading if your filter fits on the end of the lens. Look for screw-in filters that have a thin surround and mount only one or two at a time in order to minimise this effect.
With square filter system holders, the filter is affixed even further from the lens than screw-in filters, meaning you’ll definitely need to watch out for additional vignetting.
You may need to purchase a larger system or an adapter ring to hold the filter closer to lens if your holder is continuously causing you problems.
Mistakes with camera filters: 08 No lens hood
Lens hoods are frequently used in landscape photography to shade the lens and put a stop to flare. If you’re using a filter system, you most likely won’t be able to use a hood.
This is especially problematic because filters placed in front of the lens create added reflective surfaces, which are prime conditions for flare. Using your hand or a piece of card as shield will work in most instances to prevent reflections, ghosting, hotspots or loss of contrast from being a major issue.
So manufacturers do, however, make holders with hoods or hoods that can mount to the holder.
SEE MORE: 5 quick fixes to improve long exposures
Mistakes with camera filters: 09 Graduation moving during focusing
During focusing, it’s possible for the front element of the lens to rotate, thereby altering what was once level graduation. If this happens, the darkening effect won’t be placed where it’s supposed to be.
To avoid this problem, try shifting over to manual focus after you’ve brought your subject into focus in AF mode. Then you can arrange the graduated and/or polarising filter accordingly.