I bet the question of how a dead fly inside a Canon EF 70-200mm f/2.8L IS II affects image quality wasn't something most of us would have ever seen tested, but alas, the folks at Lensrentals.com decided it was time to answer the query.
From Lensrentals.com:
So, this seems like a good time to do a blog post showing that 1) this big-ass fly had almost no effect on image quality, so that little dust speck you’re frantic about sure doesn’t, and 2) getting flies (or dust) out of a lens is a lengthy and difficult process that takes a long time.
Now I think we all agree that the fly really did need to be removed, but by the time you finish this post, hopefully, you’re going to agree with me that that dust speck in your lens probably is just fine right where it is. Not to mention, I bet there’s a really good chance that if we remove this fly, the lens will never have another fly episode. If we remove some dust, though, there’s a 100% chance there will be more dust in the lens in a few weeks. Read the full article at Lensrentals.com
I'm quite glad we finally know the answer to this burning question!
Can I install it on my EOS R?
(Cue ensuing responses about birds, cats, dogs, but after that the goat can just eat the lens and the fly will no longer be a problem.)
It says nothing about being sealed against flies.
:p
What I really want is an internally focusing, large aperture, stabilized fly catcher for under $1000.
So you're saying you already knew about that from elsewhere and didn't need to read about it on a Canon-focused (SWIDT) site, and instead got alerted to a very interesting blog post? I assume you're meaning to thank CRG.
Of course it does, just not measurably so. But by the time we're using half-gigapixel sensors then we'll have to reassess.
I do hate the 'generalisation' of language. When I see a lens listing that says 'mark on objective has no effect on image', I know they're lying and I move to the next listing. Everything in a lens has an effect on image quality. Just because we can't see it right now doesn't make it acceptable to lie.
A "half-gigapixel" sensor would not render that dust-speck any more in focus and visible than today's sensors.
When I am taking pictures at rugby matches I frequently find that there are small splashes of mud on the front element of my 400mm lens but they never show up in any of the pictures. However, I once managed to leave a thumb print on the front element of my 8-15mm fish eye and you could see it clearly in all the pictures.
A fly larvae needs food to develop, don't think there enough of that inside of a lens
Did I notice it at all over maybe 10 years or more? No.
I often wonder what happened to him/her - was it the Sensor Cleaning Monster:alien: