UV Filter?
A lot of the recommendations I see around the interwebs say that it's a good practice to buy a UV filter for your lens and basically leave it on permanently.
This prompted a couple questions from me:
Is this really a common practice, or is it only common among the bloggers I stumbled across?
If UV filtering is so important, why don't lens manufacturers simply apply a UV coating to the outer layer of the lens glass?
What am I missing here?
This prompted a couple questions from me:
Is this really a common practice, or is it only common among the bloggers I stumbled across?
If UV filtering is so important, why don't lens manufacturers simply apply a UV coating to the outer layer of the lens glass?
What am I missing here?
0
Comments
You're missing one factor: UV filters are super cheap, thus they act as disposable protectors for your $$$ lens.
You scratch the filter, no problem; $20.
You scratch your lens? You're fucked.
The other 50% of photographers don't want to have anything unnecessary in the pass of the light that creates their picture, and it's a simple fact that a flat glass surface at the front of your lens will be more prone to flare than a curved one. It's easy to see flare in the viewfinder if it shows up as one of those odd bright shapes, but sometimes it might just show as a general (but often drastic) reduction of contrast and sharpness, which you might only notice once it's too late. Of course this group of photographers believes from the bottom of their heart that the ones using filters are ignorant dolts.
I leave it to you to decide who is right.
Me personally, I used filters on all my lenses for many years. When, after a once in a lifetime holiday, I got back a bunch of slides with bad flare from a 28/2.8 (with a very high quality UV filter), I took all the UV filters off and put them in a drawer. One day I should have a look if they are still there! The 28/2.8 lens in question never really had flare problems again afterward, so the problem was clearly with the filter - or maybe with that particular lens/filter combination.
At any rate, you probably don't want to use a $5 filter. And the question is if it's worth buying a $20 filter to protect a $100 - or even a $200 - lens. Of course the people with $1000 lenses don't want to use 'cheap' $20 filters to protect them...
At any rate, if you do manage to scratch your lens, you aren't really 'fucked', but the image degradation likely won't be any worth than the one caused by a cheap filter
As pointed out, if you're buying a uv filter to protect the lens, make sure it's not a super cheap one, as it will cause flare or general image quality degradation.
Here's a test on the effects of a bunch of UV filters on a lens.