The Definitive Guide to Stacking Lens FiltersThe Definitive Guide to Stacking Lens Filters

The Definitive Guide to Stacking Lens Filters

Stacking lens filters feels like a bit of a line in the sand. Some people say no way! Others say, why the frig not?

This is something we get asked a fair bit at Urth HQ. It’s a valid question and the short answer is yes, you can stack lens filters. The longer answer is that it depends on what you’re stacking and the quality of filters you use.

Lens filters have different uses and can be great fun to experiment with. Some cut out atmospheric haze in landscape shots, some reduce unwanted reflections and some reduce light intake so you can shoot in bright conditions. If a photographer is trying to achieve a combination of these things, they may decide to stack lens filters to layer the benefits.
But stacking lens filters also comes with its challenges. The main problem is that you can lose image quality because light is passing through extra layers of glass, giving it more opportunity to degrade. But if you’re shooting in challenging conditions, combining the benefits of more than one filter may result in a more usable image than one with a small loss in image quality.
In this article we will discuss the pros of stacking lens filters, along with the cons and some beaut tips on how to achieve the best shot.
The Cool
Different types of lens filters offer different photographic advantages.
CPL filters sort out any unwanted reflections, enhance the colours in your shot and increase contrast.
UV filters cut through atmospheric haze so you can get a clear shot on a bright day. They also remove the blue colour cast that comes from UV light.
Meanwhile, ND filters reduce the amount of light that passes through your lens, so you can use a wider aperture for a shallow depth of field or a slower shutter speed for beautiful motion blur effects without blowing out your photos.
“The cheaper the filter, the more affected your photograph is going to be with each stack.”

Jack Parsons

Once you’ve learnt about the merit and gain from using each individual filter, you can experiment with combining them. Say you’re trying to get a shot of a waterfall in the middle of the day. To smooth out the water with a long exposure, you might decide to use an ND filter. But the wet rocks are still throwing some nasty reflections from the midday sun, so you decide to layer your CPL filter as well. The result is a balanced shot with even exposure.
That’s the key benefit of stacking lens filters right there. You gain flexibility across the various limitations you may encounter while shooting.
The Lame
I mentioned earlier that stacking filters can result in a lower image quality. It works on the premise that the more layers of glass that light passes through on its way down the optical path, the lower the resolution and clarity of the final image. Poorly managed light will affect image quality, as will the use of bad filters. They are your two biggest considerations when stacking.
Another by-product to consider is vignetting. This will happen when something is blocking the passageway between the light source and the camera’s sensor. Vignetting can naturally occur in lenses, however, can also be increased by adding accessories. Cool if you want it, potentially annoying if you don’t. In the next section we’ll cover how to overcome vignetting if you decide to stack your lens filters.
The Tips
Before you decide to stack lens filters, you will need to critically analyse what you are shooting and work out how to best produce what you’re seeing using a combination of filters available. To do that, ask yourself these questions before stacking lens filters:
    How will my image benefit from stacking these two filters?
    Will the benefit of stacking these filters outweigh a small loss in image quality?
To avoid vignetting, bring down your aperture (if you can) to make the shot wider. If that’s not a possibility, make sure you’re photographing a frame larger than you’ll need for a final image, and you can crop out the vignetting from the edges of the image at the editing stage.
“Will the benefit of stacking these filters outweigh a small loss in image quality?”

Jack Parsons

And remember: the cheaper the filter, the more affected your photograph is going to be with each stack – so it’s worth splashing a little to have good gear on call.
The Summary
Stacking filters feel like a bit of a line in the sand. Some people say no way! Others say, why the frig not? But photography is all about experimenting, and it will often come down to what works best for the conditions you’re shooting in and the outcome you’re after. Just remember:
    It’s your art… your god damn art!!
    There are no rules.
    Exploration is paramount.
    Learn by doing.
You might find stacking filters ain’t your thing, but at least you will have the tools and knowledge in your arsenal if you ever need to call on them for a difficult or daring shot.