Filters. Old school? No longer relevant?

GENERALLY, I do not use many accessories. My camera and lens do the bulk of work. Kind of a "captain obvious" statement, I know. But there are so many accessories on the market when you browse photographic equipment sites.

IN MY case, the only accessories I use regularly are a variation of an "L" bracket, and polarizing filters. On more rare ocassions, I use neutral density filters. Over my 45 or so years of photography, I have accumulated some "stuff" including a pile of polarizing filters I do not use any more. They are good quality (B&W/Schneider Optics) filters. The primary reason I don't use them any more is that I have gone to a different system for attaching them. So, thinking maybe I could get a few bucks for them, I asked all "the regulars" (MPB, KEH, B&H, Adorama, and Used Photo Pro) for a quote on a pile of them. They declined all of them. Every filter. I was surprised.

nobody uses filters anymore

I COULDN'T help wondering why. I have had good success selling cameras and lenses. For filters, there is clearly no demand. I can only draw a couple conclusions. First, folks have - like me - completely gone over to a different filter attachment system. Personally, I highly doubt that is the reason. My second conclusion, though, is probably the more likely one: nobody uses filters anymore (obviously an overstatement - some of us still do).

WHY? I think there is a general gestalt that digital photography has eliminated the need for filters. We can now do it all, either in-camera, or post processing. I kind of understand that thought process. There is undeniably lots of editing we can do to digital images. Some of it can reproduce what some filters might do. But I think the idea that filters are no longer relevant is dead wrong!

there is a general gestalt that digital photography has eliminated the need for filters. I think that . . . is dead wrong!

THERE IS a good (even compelling) argument for some physical, on-the-lens filters. Two of them, in my view. The first, and most important, is the polarizing filter. Yes, there are methods of reducing contrast, and even some glare in most post-processing software. As well, there are many "preset" filters out there, some of them purporting to be "polarizing filters." I have used a couple of them. They are not the same thing. They aren't filters at all. They are "preset" applications (referred to as "presets"). The word, "filter" implies that it is something that is affecting the image before it is recorded (i.e., on the front of the camera lens). In very simplistic terms, what a polarizer does is filter some of the blue light waves reaching the front element of the lens and blocks them from entering. Blue light waves are very short and generally are scattered, in random directions. This scattering can cause glare. By filtering out any that are not parallel, the polarizer actually cuts the glare the lens "sees" before the image reaches - and is recorded on - the sensor. There is just no way to do this after-the-fact, in any post-processing algorithm I know.

POLARIZATION PROBABLY applies most often in two scenarios: reflective surfaces like flat water and glass; and foliage (especially fall). If you attach and rotate the filter (on a TTL viewer or one of today's EVF viewers) you can actually see it at work. There are, of course, caveats. First, if you aren't careful, you can "over-polarize" an image. This can show up as clear blue skies going from natural to unnatural dark cobalt blue. The second is that most polarizers will also cause you to lose at least a full stop of light.

There is just no way to do this after-the-fact, in any post-processing algorithm I know

THERE IS another filter that I think has (albeit occasional) utility: the ND (neutral density) filter. What this filter does is cut down on the amount of light entering the lens. Its usefulness is - in my experience - limited to those situations where you want to shoot very slow shutter speeds in ambient lighting that is just too bright to do so. I carry three of them a varying densities. I have only found two cases where I have found them personally useful. First and foremost is when shooting moving water (like waterfals or drops in streams). Even then, I find it limited, as my personal view is that the "cotton candy" waterfall look can be overdone. The second is when I am shooting a scene with clouds and would like to get some streaking as the clouds move. There are some other, very limited instances in which a filter may be recommended. If you are shooting in certain conditions (salt water comes to mind for me), you may want some protection for your lens. But in general, today's lenses are very well made and the front elements are not that easily damaged.

I never put any glass in front of my expensive lens unless there is a reason to do so

OTHER THAN the above instances, I never put any glass in front of my expensive lens glass.Having spent hundreds (or even thousands) on that expensive, high-tech glass, my feeling is that I don't want to put a cheaper piece of glass on the front of it - unless I have a good reason. But the polarizer and ND filters are worth carrying - and using for aesthetic reasons. And digital processing will not replace them.