A Canon RF 16-28mm f/2L USM is coming [CR1]

Jul 21, 2010
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My 70-200mm f/2.8L IS II USM, may it rest in peace, had dust between the front element and the one behind it, though it doesn't extend.
Of course. The back of the lens is open, so air (and dust, OMG!) get in. Zooming and focusing move element groups within the lens, and that moves around the air (and dust, OMG!) inside the lens.

Some people seem to think non-extending zooms are hermetically sealed. Lol.
 
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What happened to it? Hope it wasn’t the dust that killed it!!

I noticed IS went haywire. Gave it to a service center to fix, they claimed it got hit, and required the IS unit to be replaced + realign all the elements. The price was so high, I decided to buy a new mark III and be done with it.

If I could buy MAC insurance for 7 years, it would have been covered. Alas, around here (read: a backwater vilayet of the Ottoman empire) the longest MAC insurance around here is for 3 years. It is also insured as property with my apartment, but that one would cover the lens only if it was broken / stolen along with the camera, which works fine.
 
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Feb 7, 2019
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I noticed IS went haywire. Gave it to a service center to fix, they claimed it got hit, and required the IS unit to be replaced + realign all the elements. The price was so high, I decided to buy a new mark III and be done with it.

If I could buy MAC insurance for 7 years, it would have been covered. Alas, around here (read: a backwater vilayet of the Ottoman empire) the longest MAC insurance around here is for 3 years. It is also insured as property with my apartment, but that one would cover the lens only if it was broken / stolen along with the camera, which works fine.
That’s too bad. Our house got broken into a few months ago and my old sigma 17-50 2.8 which was sitting on the TV unit was taken. Home insurance payed out for that no problem. Bit of a price difference though of course!
 
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SecureGSM

2 x 5D IV
Feb 26, 2017
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Wider than 50mm it's easy to calculate: focal length divided by f-stop gives the size of the "entrance pupil," the hole you see when you hold a lens up and look at a white wall through it going in. So 135 f/2 will have 72mm hole for light to go in, and since the angle of view is narrow the front element needn't be wider than that.

except Sigma 105 / f1.4 Art with 105mm front element size ;)
 
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Jul 21, 2010
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except Sigma 105 / f1.4 Art with 105mm front element size ;)
The front element of a telephoto lens must be at least as large as the entrance pupil (focal length / f-number), certainly it can be larger.

All lenses need to fill the entrance pupil with light, of course, but with telephoto designs the entrance pupil is essentially located at the position of the front element.
 
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Of course. The back of the lens is open, so air (and dust, OMG!) get in. Zooming and focusing move element groups within the lens, and that moves around the air (and dust, OMG!) inside the lens.

Some people seem to think non-extending zooms are hermetically sealed. Lol.
Mine is not open. There's a lens fixed inside, not moving or rotating. lol
 
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YuengLinger

Print the ones you love.
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Dec 20, 2012
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Without noticing at first, I've gotten sand on the zoom barrel of my 24-70mm f/2.8L II. And then the inevitable grinding noise inside the lens.

Then there are misty, drizzly days when droplets get on the extended barrel and could lead to fungus in the lens.

It's not all about "microscopic" dust. The extending barrel does make the lens more vulnerable, offsetting some of the expected L build advantages.

That said, I've learned to be more careful. Would I prefer all lenses to be internal zoom? Sure! But I wouldn't want Canon to NOT make the 100-400mm just because they couldn't come up with a practical, affordable way to make it exactly the way I want...

And this reminds me of what my first photography teacher said way back in 5th grade (something we've all heard): "Photography is all about compromises."
 
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Mar 20, 2015
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Of course. The back of the lens is open, so air (and dust, OMG!) get in. Zooming and focusing move element groups within the lens, and that moves around the air (and dust, OMG!) inside the lens.

The internal elements moving don't need to expel or inhale air, though; they can displace the internal air volume through spillage around their rims.

Sealing a fixed-length lens is a magnitude easier than an extending-barrel. lol!
 
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kaptainkatsu

1DX Mark II
Sep 29, 2015
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I might be the odd man out, but what if, instead of 70-xxx, they made something like a 50-140 f/2 lens? It would most assuredly be a great portrait lens, especially if it were sharp and had great bokeh. It would definiately be the king of portraiture or at least royalty in that realm.

I want to see something like this. I shoot a lot of floor gymnastics and 70 is too long when the gymnasts come up close to you. You can crop on the long end so you don't need 200mm
 
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kaptainkatsu

1DX Mark II
Sep 29, 2015
166
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I just got my 100-400Lii last week and it's been a joy to use on the 5Div and EOS R. I've only owned constant aperture lenses until the 100-400Lii, which was my biggest turn-off with it until I used it. It might even replace my 70-200/2.8L IS.


Answer: Extending Barrel L-series lenses; not a concern.

Theres a menu option to simulate constant aperture. On my 1dx2, C.Fn2:Exposure: Same expo. for new aperture. You can have the camera automatically increase the ISO or decrease the shutter speed (or a combination of both) to maintain the same exposure when the aperture changes.
 
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AlanF

Desperately seeking birds
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Aug 16, 2012
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I noticed IS went haywire. Gave it to a service center to fix, they claimed it got hit, and required the IS unit to be replaced + realign all the elements. The price was so high, I decided to buy a new mark III and be done with it.

If I could buy MAC insurance for 7 years, it would have been covered. Alas, around here (read: a backwater vilayet of the Ottoman empire) the longest MAC insurance around here is for 3 years. It is also insured as property with my apartment, but that one would cover the lens only if it was broken / stolen along with the camera, which works fine.
I was once advised by a financial expert only to insure for events that are very rare and expensive and that you would not be able to cover yourself. Insurance is worthwhile if you are a klutz who breaks things more than average, forgets to lock up or your budget is so tight you don't have the savings on hand to replace. If you are careful, then your insurance premiums have a large factor for the nice profits and running costs of the insurance company and subsidizing the careless klutzes, and you would be far better off putting aside each month the insurance premiums into your own savings. But, having insurance keeps some people happy.
 
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SecureGSM

2 x 5D IV
Feb 26, 2017
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The front element of a telephoto lens must be at least as large as the entrance pupil (focal length / f-number), certainly it can be larger.

All lenses need to fill the entrance pupil with light, of course, but with telephoto designs the entrance pupil is essentially located at the position of the front element.

Yes, the OP statement was though : needn't be wider than that. Please see the post I have replied to.
I suggested that in many cases front element of a telephoto lens is larger than the formula suggests.
Then, OP went to explain that larger than needed front element is there to reduce vignetting.
I further explained that it was not correct as vignetting levels reduction was only marginal...

However, corner and edge sharpness was dramatically improved for obvious reason
 
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I was once advised by a financial expert only to insure for events that are very rare and expensive and that you would not be able to cover yourself.

True, except reality isn't black & white. If my apartment burnt down, I couldn't buy a new camera + 3 lenses all at once, so I added them to the contents insurance. One lens I can buy new out of pocket. What if two or more broke at the same time, e.g. because they were in a car accident?

Insurance is worthwhile if you are a klutz who breaks things more than average, forgets to lock up or your budget is so tight you don't have the savings on hand to replace.

Which is why I don't insure anything else I have, except as part of contents insurance.
 
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Photo Hack

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Apr 8, 2019
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They are still a bit top big in combinatiën with the mirroroess body imo ...
Seeing that two of them now have IS, where the EF versions did not, I would expect them to be slightly larger and heavier - especially if the trend continues of creating a lens that is sharper and performs better than the EF versions.

They also have a few more electronic tricks up their sleeves with the hardware changes to allow stored data, better focusing, and faster data communication. I’m not sure how much all that affects design, but with the addition of the control rings, that should have an impact.

And the 70-200? At least when retracted and for some of the working range, it’s certainly much smaller than the EF version.

So I’m confused on how they’re too big in combination with mirrorless? Have you used any of them yet?

Also not forgetting the 24mm shorter back flange will bring the lenses closer to the back of the camera and a body that’s a few hundred grams lighter, the girth of the lens may be the only real noticeable characteristic. The grip on my RP, as tiny as the camera is, still feels great vs my Mark IV. We’ll see.

If Canon achieves all of that on their 24-70 and is close to Sony’s physical specs on their G master, it’s a win for Canon. As it sits, Sony’s is 100g heavier and .9” longer than Canon’s EF and doesn’t have all those great additions the RF version will have.
 
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Mar 2, 2012
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Some people seem to think non-extending zooms are hermetically sealed. Lol.

Boy that would be fun. Then you’d need worry about desiccant refills in something hard to service, and they’d have to design the front element with rigidity in mind due to burst pressure for air travelers.
 
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Some people see rain, and run around like Chicken Little screaming that the sky is falling.

Some people obsess over a tiny dust speck in their lens. Almost as if it’s the apocalypse.

I have a friend who specifically looks for scratched/dusty lenses; character. haha
 
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Del Paso

M3 Singlestroke
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Aug 9, 2018
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I have a friend who specifically looks for scratched/dusty lenses; character. haha
An easy and intelligent way to get an excellent lens for much less money.
I still use my 180 mm Apo Telyt , with its cracked front lens, plus dust inside, without any quality issues. Dust is most of the time a non-existing problem that can result in a cost advantage for the buyer! ;)
 
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Some people see rain, and run around like Chicken Little screaming that the sky is falling.

Some people obsess over a tiny dust speck in their lens. Almost as if it’s the apocalypse.

I literally had my 5DIV and 70-200/2.8L IS naked in a full-on thunder storm; no rain cover at all. Canon's weather sealing is stellar.

 
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I'm guessing the 16-28mm and 28-70mm are really being aimed at people who want more DOF control than standard F/2.8 zooms in that range but are prepared to forego F/1.4 for the convenience of a zoom. In that respect would these people really want an F/2 tele zoom? unlike wide/normal range your already into decent DOF control their with F/2.8.

Maybe a range like say 70-150mm F/2 might allow for something a bit smaller/cheaper I spose and you could argue could be long enough for people who value the extra stop for light gathering shooting indoors.

These lenses don't really seem to be aiming at traditional size saving mirrorless markets but rather at people who might value a mirrorless system over a DSLR in areas like event shooters who want real-time previews and being able to shoot video though the viewfinder.
 
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