Canon Protective Filter Question

[wsmith96]

Thank you all for the feedback.   Looks like there is a strong recommendation against using Canon filters so I'll steer clear of those in favor of B+W.

[wsmith96]

I did get my B+W 007 MRC protector and it works as advertised.  Thanks again for the advice.

[tron]

I use Hoya HD or HMC Super. No reason to bother with Canon...

[Nick Gombinsky]

I don't use protective filters anymore as I'm very picky with optical quality. I used to have Hoya or Tiffen filters on all my lenses, now I just leave them "naked". I found in many situations that UV filters can cause flare and ghosting, and many times it just degrades IQ (the "digital zoom" function in Live View can be an eye opener for many things).

Anyways, the only brand on filters I trust is Schneider... and they are/own B+W.

[TAF]

...a filter is necessary to complete the weather sealing on L lenses.

I have seen this statement many times at multiple websites, but I have never been able to find any reference to this in Canon's literature.

I would love for someone to point it out in Canon's official documentation.

I just checked the instructions that come with the 24-105L (says filters sold separately), the 70-300L (also says filters sold separately), and the 70-200L 2.8 (says filters are optional).  No where does it say they are needed for anything.  I then checked my copy of the book "EF Lens Work III", and it isn't in there either.

Given how competitive the camera industry is, if you really had to use a filter to make the L lenses properly weather sealed, Nikon would have long ago sued Canon for false advertising, since Canon doesn't provide the filter, yet advertises the lenses as being weather sealed.

I suspect an urban myth.

Personally, unless I am trying to take pictures in severe conditions, I don't use "protective" filters.  I had one shatter and destroy a lens once (where if the filter had not been there everything would have been fine), and won't make that mistake again.

Which is not to say I don't enjoy experimenting with polarizers, ND's, and graduated ND's...

[neuroanatomist]

I suspect an urban myth.

You suspect wrong.  Chuck Westfall has indicated that he recommends using a filter to complete the sealing of all sealed L-series that have front filter threads (i.e. not the supertele lenses).  Hearsay, yes - but he's Canon's technical guru, so the source is a good one.

Beyond hearsay, there are a few lenses which Canon explicitly states require a filter to complete the weather sealing.  Those are lenses with front element groups that move 'within the barrel' either for zoom extension or focusing.  Check the instructions for the 50mm f/1.2L, 17-40mm f/4L, or 16-35mm f/2.8L II and you'll see the following statement:

[TAF]

I suspect an urban myth.

You suspect wrong.  Chuck Westfall has indicated that he recommends using a filter to complete the sealing of all sealed L-series that have front filter threads (i.e. not the supertele lenses).  Hearsay, yes - but he's Canon's technical guru, so the source is a good one.

Beyond hearsay, there are a few lenses which Canon explicitly states require a filter to complete the weather sealing.  Those are lenses with front element groups that move 'within the barrel' either for zoom extension or focusing.  Check the instructions for the 50mm f/1.2L, 17-40mm f/4L, or 16-35mm f/2.8L II and you'll see the following statement:

Excellent!  Thank you neuro!

The fact that they put that warning in the instructions for those lenses, and not in others (obviously I need to buy more lenses), strongly suggests to me that the need is primarily applicable to those lenses.  Your description of the why in those cases makes perfect sense.

It would be interesting to hear reasons for their use on other lenses, beyond an abundance of caution.

[dr croubie]

It would be interesting to hear reasons for their use on other lenses, beyond an abundance of caution.

I've taken my 70-300L down the beach a few times, to shoot surfers and things, the wind is always blowing a gale down there. Am I going to point my $1500 lens straight into the wind and have the front element sandblasted? Hell no, I point my B&W MRC filter into the wind, it only cost $60 or so, it has no measurable difference on IQ (as i tested on my 7D), and it's Multicoated so no extra flare in *normal* situations (i don't feel like testing it by pointing at the sun).
As to whether it's *needed* for weathersealing? Don't know, don't care. It can't make the sealing *worse*, and since it doesn't make the images worse either, then to me it's a no-brainer.
As for impact damage? Some people will claim that Hoods are better. They may be, it all depends on too many variables of height, floortype, angle, etc. Why not just use both? (And why not just don't drop it?) Hoods help a bit with less flare too. And if i dropped it i'd be more concerned about the IS elements rattling around and the mount breaking off the camera body than the outer elements smashing...

[tron]

It would be interesting to hear reasons for their use on other lenses, beyond an abundance of caution.

I've taken my 70-300L down the beach a few times, to shoot surfers and things, the wind is always blowing a gale down there. Am I going to point my $1500 lens straight into the wind and have the front element sandblasted? Hell no, I point my B&W MRC filter into the wind, it only cost $60 or so, it has no measurable difference on IQ (as i tested on my 7D), and it's Multicoated so no extra flare in *normal* situations (i don't feel like testing it by pointing at the sun).
As to whether it's *needed* for weathersealing? Don't know, don't care. It can't make the sealing *worse*, and since it doesn't make the images worse either, then to me it's a no-brainer.
As for impact damage? Some people will claim that Hoods are better. They may be, it all depends on too many variables of height, floortype, angle, etc. Why not just use both? (And why not just don't drop it?) Hoods help a bit with less flare too. And if i dropped it i'd be more concerned about the IS elements rattling around and the mount breaking off the camera body than the outer elements smashing...

+ 100000000

[TAF]

It would be interesting to hear reasons for their use on other lenses, beyond an abundance of caution.

I've taken my 70-300L down the beach a few times, to shoot surfers and things, the wind is always blowing a gale down there. Am I going to point my $1500 lens straight into the wind and have the front element sandblasted? Hell no, I point my B&W MRC filter into the wind, it only cost $60 or so, it has no measurable difference on IQ (as i tested on my 7D), and it's Multicoated so no extra flare in *normal* situations (i don't feel like testing it by pointing at the sun).
As to whether it's *needed* for weathersealing? Don't know, don't care. It can't make the sealing *worse*, and since it doesn't make the images worse either, then to me it's a no-brainer.
As for impact damage? Some people will claim that Hoods are better. They may be, it all depends on too many variables of height, floortype, angle, etc. Why not just use both? (And why not just don't drop it?) Hoods help a bit with less flare too. And if i dropped it i'd be more concerned about the IS elements rattling around and the mount breaking off the camera body than the outer elements smashing...

And when I am photographing jet engine tests, in high winds, or any other situation where I expect flying debris will hit the lens I use a protective filter as well.

But the question had become whether they were necessary to complete the weather sealing.  Now I know that some of Canon's lens do require the additional piece be added (very disappointing of Nikon not to go to court; clearly they're off their game).

As for the filter that broke, I never said I dropped it.  I didn't.  I was walking through a doorway in NYC with the camera over my shoulder and got bumped into the door frame.  The evilly  designed Canon lens cap 'ear' got shoved into the filter and it shattered.  Had the filter not been there, the cap ear could not have made it to the front element.  Hence the protective filter cost me a lens.  Unless you live in the countryside, such is an unavoidable risk if you actually carry your camera.

Come to think of it, I have become a hood guy these days.  Never really thought about it until now...

You really should try shooting directly into the sun some time.    The pictures that result can be quite beautiful.  Although as you note, you might have to remove the filter to really get the best IQ out of the situation.