Eyeman wrote:
Hello gang... I am a long-time UH stalker that finally would like a group response. We were burned out in the northern California Camp fire, and I am slowly rebuilding my gear, hence the excuse for 'replacing' my camera :>). For years I used a UV filter to protect my lenses from mechanical damage until a pro whom I respect said 'oh no.. that degrades your images'. But now with two shiny new lenses, how much really do I need to worry about that ? Thanks for your responses in advance !!
No optical system is as perfect as a thin, flat, coated piece of glass:
* No aberrations
* No distortion
* Very little tinting
* Very little absorption of light
* Very large aperture (fast and low diffraction)
* No moving parts
The commonest types of lens damage are:
* Bent filter ring
* Coating on front surface worn from cleaning
* Scratches on front surface
* Damage from moisture: spotting, fungus
Keeping a filter on the lens at all times helps prevent all these
types of damage. Ask yourself: would you rather wear out the
coating on a $20 filter or on the front element of your $2000 lens?
All lenses are a compromise. Adding corrective elements to a simple
lens can reduce chromatic aberration, but at the price of increasing
absorption and tinting. Zoom lenses are a
big compromise. But
the humble UV filter is a diffraction-limited optical system with near
perfect properties.
If a UV or plain coated glass filter cost $2000, everyone would want one.
But because it costs $20, they think it will degrade their image.. Go figure.
Sure, it adds two air-glass surfaces. So buy a coated one. But the very people
who object to the idea of adding two surfaces will happily buy a zoom lens
with 20 groups = 40 surfaces. Like I said: go figure. Human nature is not
rational--especially not with a head full of ideas that came from advertising.
Always using a lens hood is a great idea. But a lens sometimes cat get scratched
while putting it in the camera bag (especially if the bag has a zipper with a metal
grab tab). Few of us have camera bags large enough to allow a hood to be
left on the lens.
As I often say about politics: it's not about ideology, it's about outcomes.
There are far more photographers who wish they'd kept a UV (or plain coated
glass) filter on the lens than who wish they hadn't.