[wim]

Considering my own experiences, and that of a friend of mine who runs a camera store, I don;t agree.

A filter does protect the front lens for bumps and other stuff indeed. My friend regularly gets people coming into the store with damage to the lens or filter. When the lens has no filter, lens hood or not, it invariably has to be sent to the manufacturer to get repaired, which with the sub 500 € lenses generally is not worth the trouble, as it is cheaper to buy a good second hand lens. A filter not only protects the lens from a lot of debris floating/flying around, quite often it is also the seal required to weatherproof a lens, and the actual ring makes the lens mechanically stronger, so it can't bend, dent or buckle so easily. He has yet to see a front lens damaged by shards of glass from a broken filter in the 30+ years he has been in business.

A lens may still get damaged because of an impact, even when sporting a filter, but generally speaking that tends to be damage to the focusing mechanism etc., not to the optics per se, in about 20% of the cases. However, he reckons it would have been worse in most cases without a filter.

There is just one caveat: you need to use a good, multi-coated filter. A sensor reflects about 40% to 60% of the light, vs 2% to 3% from film back in the analog days, and especially when shooting in more complex light conditions, reflections and ghosting can actually destroy an image completely due to reflections of the inside of a cheaper, single coated or even one sided coated filter. In short, only buy the best multi-coated filter you can afford, clear or uv/haze. Speaking from experience here as well.

HTH, kind regards, Wim

Well, we agree on disagreeing I also disagree with the reasoning of "a friend works in a store and gets regularly in contact with people with damaged front lenses or filter". Well, what do you do when you want to ask for repair? You go to the store. What do you do when everything is fine? Going to the store and tell them like "it's the 349th day without a scratch"?

Roger stated that of 20.000 lenses 15.000 never caused a problem. To stay in the picture with the store, 15.000 lenses were sold and just do their work, but 1/4 came back to the store (a high number... I think, people care much more about their own than about rented lenses).

If you take the filter protection seriously, you need to put a protection in front of every lens you own. He said 70-120 $ for good quality filter. I paid 100,- per Ø77 ceramic protector. Multiplied by around 25 lenses: How much front elements I can send in? Less than 25, because 3 of them (11, 14, 20) don't take filters and even if: it would be a kind of a dome with a lot new problems.

Then, the 14 mm fell to the floor and broke the fixed lens hood. The front element stayed unharmed. You know the weight of 14/1.8?

Usually, expensive filters don't harm the resolution. But under front light conditions they simply add another two surfaces to reduce contrast.

I like front light and I don't like protective filters that much. That's all I can say about the subject. Oh, and of course: Stoppingdowns story is an interesting example, even if it's a once in a lifetime incident. If Murphy is in his mood, the protective filter breaks and scratches also the front element. I know, some advertise their second hand glass with the not "UV filter was always on" and most of the time I think "sure it was - or at least, is now, at the sale photo"

My friend actually is the owner of the store, and carries out lens repairs himself when he can .

Obviously, not all lenses get returned with damage, but he does get people coming in with a damaged lens at least once a week. And I've seen the results too .

And have you ever seen a broken filter scratch a lens? So far, I personally haven't. Besides, if a broken filter would scratch a lens, the impact by definition must have been so violent, that the lens would have been damaged regardless.

And as to front light conditions: did you actually test that?
My own test showed that with a really good filter transparency is even better .

I have high quality "protection" filters on all of my lenses, barring the three that can't take them .

Filters/no filters for protection always is a contentious issue, granted. However, since I had an accident with one of my lenses years ago where the filter actually protected the optics and focusing mechanism from damage, I will always use a protective filter if the lens allows me to do so. This lens set me back a month of my salary back in those days, I used it a lot, and as I am not a professional photographer, I was happy I had a filter mounted; it is entirely worth it to me .

Kind regards, Wim