The Showdown: Fixed ND Filter vs Variable ND Filter

Neutral density (ND) filters are a landscape and outdoor photographer’s best friend. They let you control light exposure so you can widen your aperture in bright light or slow down shutter speeds to create motion blur.

When it comes to choosing ND filters, you’ve got different options at your disposal including fixed ND filters and variable ND filters. But should you opt for a fixed ND filter or a variable ND filter? You probably have lots of questions, like what’s the difference between them, which is better for different types of photography, and variable ND filters are newer to the market so are they any good?

Keep reading for guidance on which one will be best for you.

ND filters restrict light entering a camera lens, measured by stops of light called f-stops. A filter rated with a smaller number like an ND2 cuts out only 1 f-stop and therefore lets more light into your camera compared to, say, an ND1000 filter, which cuts out 10 f-stops of light.

A fixed ND filter blocks a set f-stop of light whereas a variable ND filter covers a range of light exposures, typically from around 2-10 f-stops, although this can vary.

By rotating the front element of a variable ND filter you can change the amount of light being blocked without needing to stack or swap out filters. If you want to change your exposure while using a fixed ND filter, you’ll typically need to stack several fixed ND filters or swap it out for a stronger one. More info on ND filters and f-stops here.

Whether you choose a fixed ND filter or a variable ND filter depends on the type of images you capture and what suits your shooting style best. Both offer great benefits to photographers so there’s no right or wrong answer but there are definitely certain scenarios where you may prefer one filter type over the other.

Variable NDs offer great convenience for photographers who work with changing light conditions, like in outdoor or travel photography. They’re especially useful when you need to shoot fast or if you want to experiment with different settings.

Fixed ND filters are preferable when shooting subjects in stable, unchanging light such as in a studio setting, or in relaxed shooting conditions where you can take your time to change filters if needed. Plus, you can stack them but be aware of vignetting and cross-polarization.

When working in a studio it’s easy enough to keep several fixed ND filters at hand so you might not need the more expensive variable filters. But if you’re out and about a lot when shooting, having one variable ND filter saves having to load your kit bag up with multiple fixed ones.

If you shoot videos, a variable ND filter is advantageous to keep shutter speeds slow and constant, which can be hard to achieve in light that is bright but constantly changing. It’s also useful when trying to achieve both high image quality and shallow depth of field in environments where the light is a bit bright.

One thing to be careful of when using variable ND filters is that when you push the filter past its maximum settings, an X mark appears on your image. This happens more frequently when using lenses with wide angles. A cheaply made and badly designed filter also often affects image quality and can produce an unwanted colour cast.

If you want to learn more about the technicalities of shooting with a variable ND, including when and when not to use, check out our article ‘Everything You Need To Know About Variable ND Filters’.

At the end of the day, the decision’s mostly going to be made clear when you look at how you shoot. If you’re the kind of photographer who’s got the time for slow, considered shooting and proper mise-en-scene then you’re probably better off with a fixed ND filter or two. If you’re the kind of photographer who is looking for convenience, options to experiment with, and needs to make fast decisions while shooting, a good variable ND filter is probably what you’re looking for.

Whether you use fixed or variable ND filters, always purchase them with good build and quality in mind for better images, a longer lasting kit and peace of mind while shooting.

Did you know Urth makes variable ND filters and fixed ND filters that reforest the world? Five trees are planted in deforested areas for every filter purchased. Shop our range of ND filters here.