Filter or not for 70-200 f2.8 MkII

Any value from weather sealing that the L lenses gives requires a filter. I have taken to transporting my lenses with a filter and then if there is no blowing water or threat of it, I end up taking them off.

I have taken several photo classes in the past year and none of the professionals I dealt with used filters. Again, just personal opinion.

Nope, no "protection" filter for any of my lenses all the time... I simply don't want anything getting in the way of taking a great shot. After all, I bought my lenses to take photos, not to coddle and protect them. Thirty years shooting, 30,000 to 60,000 images a year.... have yet to ever have a lens get damaged just with reasonable care (hood when shooting, capped when stored).

Yes, I have filters for various purposes and I don't hesitate to pull one out and install it when it serves a real purpose. This includes "UV" filters for "protection" if circumstances actually call for it (which happens three to six times a year... maybe). I'll usually use a filter shooting at the seashore, salt spray is nasty stuff and hard to clean off. I'll also use one shooting in blowing sand storms, or sometimes at sporting events when there's risk of flying particles. But the vast majority of the time, I will not use a protection filter. Putting one on a lens 24/7/365 seems utterly counter-intuitive to me.

If using a filter, there will always be some image quality degradation... You are forcing light to cross two additional air-to-glass boundaries and that will always have some effect. It might be very little loss with a top quality, multi-coated filter in most situations... But in difficult lighting even the best will show some increased flare, lower contrast, reduced color saturation, more chromatic aberration than a bare lens will. Always remove all filters when shooting into the sun or other really strong light sources. Cheaper, lower quality, single-coated or uncoated filters can cause issues all the time... softer images, a lot of increase in chromatic aberrations, lots of flare, interference with AF accuracy, etc.

People cite "a filter saved my lens"... but there is no way to prove that the lens wouldn't have fared just as well or better without the filter. On the other hand, I have seen lenses ruined when a filter got broken, when the sharp glass of the filter gouged the front element. So, IMHO, mindlessly installing a filter on there all the time actually increases risk, it doesn't reduce it. As a result, when using a filter it's even more important to cap the lens when it's stored and use a hood while shooting with it.

There is very marginal increase in sealing to some lenses, when a filter is installed. Of course Canon recommends installing one... Canon sells ridiculously overpriced filters and are in business to make a profit! Lenses that see a small increase in sealing (improved water/dust resistance.... none are ever fully waterproof or dustproof) include the 17-40L and 16-35L, for example. But not any of the 70-200s. None of the IF or "internally focused" lenses will see any add'l sealing with a filter. And any lens that's not internally zoomed is more vulnerable at the barrel joints, than anything the filter will help cover.

I put on a filter when at the beach. I don't see any degradation of image quality with it on. The salt air, sand, water will collect onto glass and everything else. I feel better with a filter on in this situations and other moist air conditions. With alot of kids, I do also. They like to stick their dirty fingers onto the glass.
Urban, night shoots, no filter because of added potential flare issues from say street lights.

hoya hd filters are excellent filters and do not degrade IQ

I use a Zeiss filter and still get amazing color and IQ. Haven't tried w/o it yet. Avoid the cheap ones, if you decide to use them.

For that particular lens, I'd use a filter. Here's the one I'd choose and the reasons why:

http://www.amazon.com/​review/R2FY5PNUJ9SMLX/

In brief, there won't be any image degradation and the cost of filter is slight relative to the loss in value from front element damage.

One thing is for sure: You should perhaps definitely use one or not use one all the time sometimes.

filter & hood
If you see sun spots or flares remove the filter

I want to protect my expensive lenses, so when I upgrade I can get the max for the old stuff on Ebay.

I use a lens cap to protect my lenses.

I have a Hoya UV filter that I'll use if I'm near blowing sand or water but that's about it.

Minor scratches on the front lens will effect resale value but don't usually do much to degrade IQ so unless you are a gear flipper I wouldn't worry too much anyways.

Is the b+w xs-pro a good choice?

The front element can take some rocks as I found out here. My hood was full of rocks and dirt. A bit of risky move I suppose lol. However no scratches or chips or anything wrong. I see people say "oh this rock smashed my filter, thank god I had it.. well a filter is thin and it probably will get smashed. I personally only use like CP's or graduated ND for specific things, but never for protection.

IMAGE LINK: http://www.flickr.com …shiftonephoto/6​963339675/

I stopped using filters when I saw how badly even a good one degraded the images from my 100-400L. After my first outing with the 100-400L, I actually thought it was defective. It was just the B&W UV filter. Shoot the same scene, from a tripod, with and without a filter on your lens. If you don't mind what the filter does to your $1,000 lens, leave it on. I invested in a bunch of hoods for my non-L lenses. You can get aftermarket hoods, that don't adversely affect your image quality, for about $5. With the money I'm NOT putting into filters, I can afford to replace a front element. Oh, I've been shooting SLRs for almost 40 years. I've yet to scratch/break a filter or front element.

I honestly switch back and forth from using filters to not using them... I must admit, I never seen ANY IQ drop with any filter I have used. And I like the ease of cleaning without worrying about the front element. That is really the only reason I use them.

I use decent filters on my lens (B+W XS-Pro MRC) and am hard pressed to find situations where I see a noticeable difference between using filter and not using one. Therefore, my default is to have the filter on. I can always remove the filter if I feel the shoot will benefit.

By using a filter, I don't have to clean the front element that often, or worry about putting on the filter at the last minute when I need the protection (e.g., at the beach or in heavy mist or rain).

If I shot professionally, I might feel differently about this as I would have more time to prepare before shooting. But, photography is my hobby and keeping the resale value of my glass high makes a lot of sense.

allancold wrote in post #15411507
Is the b+w xs-pro a good choice?

Yes those are very good.