I still use glass filters on my camera
Recently I came across a YouTube video “exposing” ph`otography accessories one no longer needs in the time of AI-assisted photo editing. One of the accessories the author claimed was no longer necessary was optical glass filters. Undoubtedly, iPhone and Photoshop marketing wants us to think that way.
I disagree.
Optical filters may not be necessary anymore for their original purpose, but I do not use them in that way. I use them to create unique photographs and a way of shooting which suits me.
- UV filters are no longer necessary. True, most modern sensors have built-in UV filters, but film does not. True, most modern lenses are pretty scratch resistant. True, adding any layer of glass degrades lens performance. I love the peace of mind. I can afford a new UV filter every year (even an expensive B+W one), but I can only afford a new lens every ten years.
- I am on the fence about graduated neutral-density filters. Lightroom does such a convincing job with linear gradient filters that ninety percent of the time, the viewer cannot distinguish if the effect was post-production or through a graduated ND filter. Then there is always exposure bracketing and HDR.
- Polarizing filters can be simulated in NIK color effects or photoshop. True, some settings in Photoshop and other specialized programs mimic polarizing filters. They shift the color spectrum to mimic the effect, but clearly, they are not polarizing light hitting the sensor. (a) Polarizing filters reduce haze in landscapes. This can be achieved in post using the clarity slider or the “dehaze” slider; however, it is easy to “over-dehaze,” resulting in unnatural images. (b) Polarizing filters create more excellent color and tonal saturation. This effect, too, can be completely simulated in post; however, I use those filters to achieve other effects, e.g., to simulate color film profiles. It simply is easier not having to worry about it. (c ) Polarizing filters eliminate reflections and glare, such as from water. That, too, can be achieved in post, but now we are talking localized adjustments of potentially many different objects and colors. That takes a lot of time to get right. This “simple” piece of glass saves hours of post-production.
I use my polarizing filter like a two-stop neutral density (ND) filter combined with a UV filter. This logic applies to daylight outdoor photography and street work. Even on modern cameras, the shutter speed is limited. So is optical performance beyond f8 and ISO below 100. If it is too sunny and I need a shallow depth of field, or I want to freeze water, only an ND filter can get the exposure triangle into the right place. I always leave mine on and only take it off for night shoots. Note that polarizers can give vignetting for wide-angle (< 35 mm) lenses.
I even use color filters because I love my monochrome camera. This is a very niche application because of a very particular sensor. On a monochrome camera, only gray scales are recorded. The Bayer filter is removed, and with it, any interpolation for color. Naively spoken, this triples the resolution. A deep red filter makes the clouds pop while maintaining resolution. This effect can be reproduced during color-to-black-and-white conversion but not if the starting material is a grayscale image. Clouds are notoriously challenging to select.
