Twelve filters for digital: what’s hot and what’s not

B+W 491 redhancer

Hot

1. B+W 010 MRC – pretty much the highest-quality protective filter that exists, the B+W MRC resists flare, dust, liquids, and fingerprints. This can be swapped out for a KR1.5, though the tone difference is so small as to be negligible. The newer Nano versions repel water even better, but probably not as much as their 40% premium would suggest. If your primary goal is killing UV haze in the mountains, the fabulously expensive B+W 415 is a better choice. It has only a single coating and no water repellent characteristics, but it has pretty much the highest UV blocking power you can get without a color cast.
2. B+W 491 Redhancer (2x) – as far as red enhancing filters go, this is the real deal. Using the same Corning glass as Howard Ross did when he invented the enhancing filter, this one selectively cuts alternative colors, which makes reds, yellows and oranges stand out from each other. It has a flat suppressive effect elsewhere. This is not a filter whose effect can readily be replicated using Photoshop, but sadly, it is becoming extinct. You can still get the less impressive versions from Hoya, Marumi, or Tiffen. A couple of cautions that might make you think twice about making this “the new UV.” One is that rare-earth glass often suffers from humidity damage (corrosion). The other is that it does not block very much UV light.
3. 80A/KB15 (2.2x) – automatic white balance has not rendered the tungsten correction filter obsolete – because incandescent light is deficient in blue – and blue is the noisiest channel when amplified. If you are shooting this filter in room light and balancing with a flash, be sure the gel the flash with an 85 to make it the same color as the room lights.

Warm

1. Infrared filters (720nm) (~1,024x) – Infrared was a real pain back in the day. But most digital cameras have so much infrared contamination that when a 720nm filter is screwed on, they expose just like old-school infrared film (as in barely shootable without a tripod on a bright day). These filters work the best on contrast-detect AF cameras that automatically compensate for focus shift. You can get a 560 or 650nm filter for “false color,” but they focus less precisely – and the result may be mistaken for a Japan Air Lines travel poster featuring cherry blossoms. An 800nm+ is an option for true monochrome IR, but it is difficult to focus.
2. B+W 486 UV/IR cut (1x) – this oddball interference filter is most often associated with the Leica M8. It has coatings that  cleanly kill UV (at least as well as a UV filter) and IR.  “Infrared,” you ask, “isn’t that filtration built into the camera?” Yes and no. Digital cameras attentuate IR light but do not completely eliminate it. That’s why you can screw a 720nm filter onto an unconverted camera and (barely) shoot a daylight picture with it. Further, camera AF systems are not aided by IR contamination in the red channel. The catch? You can’t use it on lenses wider than 35mm field-of-view.
3. FL-D  – the rise of compact fluorescents is reason to revisit these filters that kill the sickly greenish glow. If only they made a version for LED light bulbs. Soon, my children, soon.
4. Cokin – these filters can be uncontrollably cheesy. But for an average price of five bucks apiece on the used market, you can have a lot of fun without cracking open your post-processing software or doing the same retrofilters as the fauxtographers you look down on. Mirrorless cameras are quite easy to use with them. If your taste is more conservative, Cokin has a decent selection of good grad filters, two-color polarizers, and other landscape staples.

Cold

1. ND8x – unless you are shooting an f/2.8 lens, most modern cameras that go as low as 200 ISO can shoot wide-open in sunlight. Some cameras now have ND filters built-in (c.f. Fuji X100/X100s).
2. Circular Polarizers – circular polarizers are needed only when you are metering through a semitransparent mirror. If you don’t have a DSLR, you can get away with a linear polarizer from the junk bin at your local camera store. That said, the need for any type of polarizer is usually exaggerated. If you want to experiment with polarizers, start with the junk bin at your camera store.
3. Diffusers – soft-focused pictures are good for the 1980s, but that was 30 years ago. But they’re still perfectly good for nudes with perms.
4. Round graduated ND filters – grad filters are already endangered by Lightroom. Use them if you don’t like computers. But if you don’t like computers, why shoot digital? And round graduated filters are inflexible (you can’t move the “horizon,” which can be pretty critical).
5. Clear digital filters – why do these exist? Why not just an UV and get something out of that extra flare?