Test: Do UV filters protect the lens or not?

[Jan Anne]

For those whom still think a fragile UV filter is any good for protecting the front element:
https://youtu.be/P0CLPTd6Bds

Conclusion for the impatient; it doesn't, just use the hood.

[Ian R]

One thing spending time repairing lenses has told me is that any impact damage - especially that which is hard enough to even dent a filter ring - will have also caused damage inside the lens. I no longer buy any lenses with any impact damage as they will not work as they should. Even rock solid MF Nikkors will be affected - the focus and CRC helicals are not designed to be bashed and the elements may be decentred and infinity stop knocked out of calibration. Zooms are worse still - I have stripped and rebuilt a few impacted Nikon zoom lenses and my last project - a 28-105mm - was dropped, yet looked fine on the outside. Inside the metal cam follower had been bent and the action was wrong - and photos were less clear than they should be.

I look at is as this. I use a protector to look after the front glass from ever needing to be physically cleaned - and take care to not drop or strike lenses. The filter to me is nothing to do with protecting against rough handling - where did this line of thinking come from anyway? I have managed 20 years with only one drop - a 105mm f/2.5 - and that fell on its side, bruising the metal. On checking the lens I noted that the focus was a bit stiffer than before the drop so I donated it to a charity shop and got another.

So I use a filter to protect against airborne pollutants and foreign matter but I don't expect the filter to have any bearing on drops or impact - why should it?

[Bjørn J]

Surprising to see how strong the front element of a lens is. I use protector glass (filter) only when I risk saltwater spray or flying sand on the lens.

[Jacques]

I have a NC filter fitted to each of my three lens together with the supplied lens hood purely to protect the front element as much as possible from the UK weather and to  allow cleaning to be done even if I am out and about without a photographic cleaning cloth, I would not expect a filter to protect against impact damage, minimise the possible damage maybe ?

[Sash]

I once dropped my camera, I stumbled and fell right in front of Bellagio casino, my camera flew a couple of meters and smashed the pavement with its lense down. There was a mark left on the filter's  metal rim. No marks on the camera or lense whatsoever. It worked just fine afterwards:

[Akira]

The challenge goes on...

http://www.dpreview.com/articles/6109265947/hoya-hd3-lens-filters-claim-to-be-4x-stronger-than-optical-glass

The test video...

https://www.youtube.com/watch?v=C1JVjeleW6A

[Akira]

Surprising to see how strong the front element of a lens is. I use protector glass (filter) only when I risk saltwater spray or flying sand on the lens.

I think that all of the tested lenses have convex elements at their front which are understandably much stronger than a thin plain filter glass.  Concave front element of wideangle primes and zooms should be way more vulnerable.

That said, I do think that the test is a good food for thoughts.  Thanks, Jan, for sharing!

[pluton]

We must try to be kind and patient toward our fellow humans that, by accident of mental ability, cultural gullibility, or growing up in a sheltered or ignorant life, do not have the knowledge of everyday, practical physics to realize that the rigid metal and glass thing, 99% of the time, is not going absorb shock or otherwise protect the thing to which it is attached against physical impacts.
Good protection against impact is a Pelican case with 3 inches/7 CM of foam around all sides of the object being protected.
I have clear filters available for all lenses, and use them mostly on wide angle lenses that have shallow lens hoods, which offer less debris protection than the deep hoods of the telephotos.  I often need to wipe dust and debris off the front of the lens with my shirt or other potentially contaminated cloth.

[Sash]

We must try to be kind and patient toward our fellow humans that, by accident of mental ability, cultural gullibility, or growing up in a sheltered or ignorant life, do not have the knowledge of everyday, practical physics to realize that the rigid metal and glass thing, 99% of the time, is not going absorb shock or otherwise protect the thing to which it is attached against physical impacts.

As the one who have been ignorant enough to study strength of materials, stress-strain-relations and fracture mechanics many years ago, I can say that your statement is not entirely correct. 

[pluton]

As the one who have been ignorant enough to study strength of materials, stress-strain-relations and fracture mechanics many years ago, I can say that your statement is not entirely correct. 

Please correct me or clarify as you might wish. 

[Gary]

I use protective filters on all my lenses. If I shot in a controlled environment I probably would not use protective filters. I used to be a professional, as such the only thing that mattered was the final image. I have been in situations where I've lost the filter but was able to continue shooting and complete assignments by simply by removing the destroyed protective filter. Could the front element have survived the 'attack' (ballistic impact/chemical/abrasive) in all these confrontations and continue to function? I don't know, but each and every time I am glad the protective filter was in place (RIP protective filter). I always use hoods and I am a believer of Murphy.