How to protect 300/2.8 front element?

Normally I put a UV filter on my lenses, strictly to protect the front element's coating. How would I protect the 300/2.8's coating?

Ok, I'll take the bait. Even the best UV filter in the universe is going to have some negative impact on your results. I find that unacceptable when I pay a truckload, or maybe a bit less, for a lens. Remove the filter. Use it as the world's most expensive coaster, or discard. Mount the appropriate hood to the lens. If you are not working in salt-spray or flying mud/sand, you don't need a filter to protect your lens.

Fire at will.

PentaxShooter wrote in post #18989684
Ok, I'll take the bait. Even the best UV filter in the universe is going to have some negative impact on your results. I find that unacceptable when I pay a truckload, or maybe a bit less, for a lens. Remove the filter. Use it as the world's most expensive coaster, or discard. Mount the appropriate hood to the lens. If you are not working in salt-spray or flying mud/sand, you don't need a filter to protect your lens.

Fire at will.

I'm not (mostly) worried about the environment damaging the lens, but rather that I'll damage the coating when I clean it. Using a microfiber, a blower, and a lens brush all help to delay the inevitable, but my lenses cost so much that I want it to never happen... So I clean the UV filter instead.

IIRC, the 010M's impact on sharpness was indiscernable, and increased lens flare was very minimal (and I usually avoid any lens flare anyway), but I'm open to hearing otherwise.

I don't buy glass in that price range. But, some of the lenses I do buy are very expensive by my standards. Using blower, then brush, then microfibre cloth has never marred any of my lenses. I don't own a UV filter. For dog-boogers and kid-prints my cleaning process is: beat said offender to within an inch of his life (optional), insure no particulates on lens, use a drop of lens cleaner on microfibre cloth to remove aforementioned grime.

All these years and all these professionals using equipment in all kinds of settings, and companies haven't taken into account that their products will be regularly cleaned?

Once you get your first supertele you either join the 'no protective filter' club or use cling film.

Which version of the 300 2.8 do you have?
The versions before 300 2.8 IS II already have a protective filter as part of the design.
The version II and III superteles no longer use them.

Choderboy wrote in post #18989710
Once you get your first supertele you either join the 'no protective filter' club or use cling film.

Which version of the 300 2.8 do you have?
The versions before 300 2.8 IS II already have a protective filter as part of the design.
The version II and III superteles no longer use them.

I don't have any yet. I want to get version I.

What's the protective filter that they use?

Edit: I just realized that I was (seemingly) lied to. I read that the I and II are almost equal in sharpness. But based on the only site I found with a specific comparison, that's not true. Dang it.

The protective filter is part of the design. Obviously, it's at the front. So it's the front element.
Filter is actually not the correct term. Protective front element is correct.

icor1031 wrote in post #18989687
I'm not (mostly) worried about the environment damaging the lens, but rather that I'll damage the coating when I clean it. Using a microfiber, a blower, and a lens brush all help to delay the inevitable, but my lenses cost so much that I want it to never happen... So I clean the UV filter instead.

IIRC, the 010M's impact on sharpness was indiscernable, and increased lens flare was very minimal (and I usually avoid any lens flare anyway), but I'm open to hearing otherwise.

.
I know lots and lots of pros who use big lenses like the 300 f2.8 and larger. . They ALWAYS keep the factory lens hood on, no exceptions (except when packaged to ship or take on a plane).

The hood has remained on my 300-800mm since I returned from Alaska in June of 2018. . Absolutely no viable need to take it off for anything, ever. . The deep hoods that come with big lenses create a deep "well" around the front element, which keeps rain and snow and salt spray and dust and mud and everything else from getting on your lens in 99.99999% of all situations.

I have never known any pro who ever used any kind of protective filter on a big lens (and the vast majority of pros never use any filter on any lens .... heck, many of them don't even bother to use lens caps on their smaller lenses.

As far as cleaning the front element goes, it will only be very, very rarely that that will ever need to be done. . I often go 3 to 5 weeks without so much as even giving it a quick swipe with a dollar store microfiber cloth. . About once a year some event may cause heavy spotting on the front element of my big lens, and then I have to take two or three minutes and actually clean it with lens cleaning fluid. . But that is only after something really exceptional happens, like having it facing upwards in a rainfall or getting salt spray on it from the ocean.

I know you're not a noobie by any means, so I am a little puzzled over your apparent concern about cleaning and protecting your front element. . The front element will be exactly the same after 10 years of heavy use whether you clean it religiously or completely ignore cleaning it for months at a time.

This is a case in which "taking care" of something does not in any way prolong its usefulness or protect it from some serious wear or damage. . And the photos themselves will be exactly the same, right down to 400% pixel-peeping views, whether there's a bit of dust on the lens or not. . A perfectly clean lens simply doesn't produce images that are any better in any way than those taken with a bit of dust on the lens.

I realize that this is a bit of a rant, and that I sound quite adamant and forcefully opinionated, but it has always bothered me in the extreme to see people concerned about something that doesn't require any concern. . It's a character trait that bugs me to no end!

.

For my 300mm 2.8 I, I use the hood as much as possible, and always keep a cover on it when not in use. I don’t use the OEM leather cap monstrosity because I find it a pain to use. Instead, I found out that a Pyrex 7200-PC 2-cup glass bowl lid fits the end of the 300mm V1 perfectly and takes up way less time to put on/take off and much less space in a bag (I also cut the center out of one and made my own custom-fit sun filter for shooting eclipses). I’m usually shooting in dusty environments like softball fields and I’ve not really seen the need to do any serious cleaning to the front element. It gets dusty of course, but a rocket blower and a microfiber cloth always seem to do the trick. I don’t really worry about it that much since it’s recessed into the lens a bit, even without using the hood. I understand wanting to keep your gear clean and like new, but it would take quite a bit of dust/dirt or even scratches to make any difference whatsoever in the final image.

MakisM1 wrote in post #18990073

Hosted photo: posted by MakisM1 in
./showthread.php?p=189​90073&i=i265907011
forum: Canon Lenses

Dropped my day-bag with the travel rig (Canon 60D + EF-S 18-200). The lens was pointing to the (lightly padded) bottom (the only way it fits mounted).

The bag landed on its feet, ergo the lens landed on its face.

The lens cap got driven into the '0' filter. Said filter gave its life to protect the lens. The hood would have protected the lens, but the combo would not had fitted the bag.

YMMV

The reason the filter broke is because it is made from very thin glass; it didn't protect anything. The broken shards of glass were more likely to damage the front element of the lens then not having a filter on in the first place.

icor1031 wrote in post #18989711
Edit: I just realized that I was (seemingly) lied to. I read that the I and II are almost equal in sharpness. But based on the only site I found with a specific comparison, that's not true. Dang it.

In the past I owned the 300 f2.8 IS, later upgraded to the version II. I don't have any test photos that compare the sharpness of these lenses, but I would be hard pressed to tell a difference in sharpness between the two. Not saying that there is no difference, just that the difference is negligible. Of course this is my opinion.

One advantage I found with version II is how much better it works with the 1.4xIII and 2xIII. Better sharpness and contrast, and improvement in AF performance. Again, this is my opinion based on my experience with the two lenses. I have no data to backup my claims. Also, version II is a little lighter in weight and has more stops of IS. I don't believe Canon still services version I. If you can get version I at a good price, I think you will be very satisfied with it.

About cleaning: I always use the lens hood, and a blower brush for the dust. On time I used the lens on a half-day boat. The ocean mist put a light film on the front element. I cleaned it with ROR and a microfiber cloth. Good as new. Had to clean the lens this way 3 or 4 times. The lens coating seems to be intact.

Good luck with your lens!

john crossley wrote in post #18990143
The reason the filter broke is because it is made from very thin glass; it didn't protect anything. The broken shards of glass were more likely to damage the front element of the lens then not having a filter on in the first place.

Wrong!

The extra depth afforded by the filter had the cap wedged into its 'barrel' and never touched the lens. The shards did not introduce any damage, much to the disappointment of the "No Filter Mujaheddin" I imagine.

I actually had to unscrew the filter with the cap wedged in it, to remove them from the lens. Had the filter not been there, the impact would be directly on the lens with whatever concomitant damage to the first element.

Have a nice day!

MakisM1 wrote in post #18990073

Hosted photo: posted by MakisM1 in
./showthread.php?p=189​90073&i=i265907011
forum: Canon Lenses

Dropped my day-bag with the travel rig (Canon 60D + EF-S 18-200). The lens was pointing to the (lightly padded) bottom (the only way it fits mounted).

The bag landed on its feet, ergo the lens landed on its face.

The lens cap got driven into the '0' filter. Said filter gave its life to protect the lens. The hood would have protected the lens, but the combo would not had fitted the bag.

YMMV

So how does the OP use this information regarding a 300 2.8 with no option for a filter in front of the front element?