Digital. Means “new”. “hi-tech”. And “need new stuff”, “short lifecycle”.
I have seen “digital” filters in stores. And I have seen digital lens cleaners, digital everything else.
Well, to this I have two notes.
First: “digital” is often used just to get you to buy things. Digital sounds new, and new, in Don Draper’s words, is an itch you desire to scratch. A way to get you to buy. The reality: if you use a protective filter on your camera, an “analog” filter will do just as well. There’s no difference. A filter is a filter.
The same goes for many other “digital” items: digital lens cloths? Really?? Caveat emptor: buyer beware; Careful what you pay for; or rather, careful that you really need it.
Second note… I do not use filters. As regular readers will have seen here, few pros put filters on their lenses in normal use. Yes, I do own the filters: when it is raining, snowing, I am in a sandstorm, at the beach: that is when I will put on a filter to protect my glass. Otherwise, it just adds flare and unsharpness (see my post in June).