Lens Filters: Which Ones Are Still Useful in the Digital Age

In the film era, filters were essential for correcting or transforming an image right at the moment of capture. Digital sensors and editing software have made some of them redundant — but not all: a few remain irreplaceable, for reasons post-processing simply cannot reproduce.

The UV filter, protection more than effect

The UV filter, once used to correct a bluish haze on film, no longer has any real visible effect on a modern digital sensor. Many photographers nonetheless keep one permanently screwed on for a different reason: protecting the lens’s front element from scratches and dust — a filter being far cheaper to replace than a damaged lens.

The polarizer, an effect impossible to recreate

The polarizer cuts reflections on water and glass, and deepens a blue sky by boosting the contrast with the clouds — an effect that depends on the actual angle of the light at the moment of capture, and that no editing software can faithfully reproduce afterwards. It’s probably the filter that retains the most relevance today, particularly for landscape work.

The ND filter, for slowing down the light

The neutral density (ND) filter reduces the amount of light reaching the sensor without shifting the colours: it makes a slow shutter speed possible in broad daylight — to smooth the water of a waterfall or blur moving clouds — where the available light would normally rule it out. Once again, an effect that happens at capture, not in editing.

Colour and effects filters, replaced by digital

Colour-correction filters and special-effects filters (starburst, soft focus), widely used in the film days, have today been largely replaced by digital editing — more flexible, reversible, and with no compromise on the lens’s optical quality. Their appeal is now mostly creative, for those who prefer to get the effect straight out of the camera rather than in post-processing.