Here are the specifications for the Canon RF 100-500mm f/4.5-7.1L IS USM

FrenchFry

Wildlife enthusiast!
Jun 14, 2020
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I’m curious what the price will be and if it will work with the converters. Because under the bright African sun f14 is usable

btw what do you guys mean with the iq
While specs are a nice teaser, we're waiting to see what the IQ is out of this lens still, given that there are no sample images to pixel peep yet. If the image quality out of this L lens is as great as people have come to expect out of RF glass, people who would generally purchase this type of lens will generally be quite happy.
For anyone who prefers to shoot with native RF lenses, this lens is probably the only long telephoto L lens available for the next year or two. This lens is thus likely to be carefully scrutinized by wildlife shooters to see if its performance and IQ will match or exceed the far more numerous EF lenses that can be adapted. If it's good enough, and the autofocus and low light performance of the new bodies are also good enough, this lens could entice quite a few DSLR owners to at least partially migrate over to the R mirrorless system.

But we won't know for sure until we get more info about the image quality of this lens!
 
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bmfotonet

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Maybe someone can answer, why do manufacturers always choose to start with such slow apertures on the low end of these zooms? Is it purely a cost issue or is there inherent design issues with starting a 100-400 or 100-500 at 2.8?

Aperture is a ratio of how wide the pupil can open relative to the focal length. A longer lens needs a wider pupil to achieve the same f stop as a normal focal length lens. In practical terms, it's relatively easy to make a 50mm f/1.4 but it would be almost physically impossible to make a 500mm f/1.4 because the lens would have to be impossibly huge. Look at sizes for lenses like the 200-400mm L f/4 or any of the super teles. They are massive lenses because the aperture has to be massively wide at those focal lengths to achieve a fast aperture.
 
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Aperture is a ratio of how wide the pupil can open relative to the focal length. A longer lens needs a wider pupil to achieve the same f stop as a normal focal length lens. In practical terms, it's relatively easy to make a 50mm f/1.4 but it would be almost physically impossible to make a 500mm f/1.4 because the lens would have to be impossibly huge. Look at sizes for lenses like the 200-400mm L f/4 or any of the super teles. They are massive lenses because the aperture has to be massively wide at those focal lengths to achieve a fast aperture.

I think he meant why can a 100-500 not be 2.8 at 100 and 7.1 at 500.

I'm curious about this as well...
 
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bmfotonet

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I think he meant why can a 100-500 not be 2.8 at 100 and 7.1 at 500.

I'm curious about this as well...
ah yes, I can now see that that was the point of his question. I don't know other than to theorize that there are some limitations in the optical formula that prevent it. f/2.8 at 100mm would make it a far more versatile lens for things like portraits.
 
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AlanF

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Aug 16, 2012
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Aperture is a ratio of how wide the pupil can open relative to the focal length. A longer lens needs a wider pupil to achieve the same f stop as a normal focal length lens. In practical terms, it's relatively easy to make a 50mm f/1.4 but it would be almost physically impossible to make a 500mm f/1.4 because the lens would have to be impossibly huge. Look at sizes for lenses like the 200-400mm L f/4 or any of the super teles. They are massive lenses because the aperture has to be massively wide at those focal lengths to achieve a fast aperture.
Sigma makes a 200-500mm f/2.8 - it's only $25,999 https://www.bhphotovideo.com/c/product/551435-REG/Sigma_597101_200_500mm_f_2_8_EX_DG.html
 
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Maybe someone can answer, why do manufacturers always choose to start with such slow apertures on the low end of these zooms? Is it purely a cost issue or is there inherent design issues with starting a 100-400 or 100-500 at 2.8?
D = Lens Diameter (in mm)
F = Focal length
N = F-Number (or perhaps T-number to be more precise)
And we have a formula relating them:
N = F/D
The smaller N requires larger D for a given F.
There are weight and cost constraints with larger D.
 
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brad-man

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Jun 6, 2012
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I’m curious what the price will be and if it will work with the converters. Because under the bright African sun f14 is usable

btw what do you guys mean with the iq
This is so far the only lens that Canon has said was compatible with the converters.
iq = image quality

Edit: This lens + the 2 new collapsible primes are compatible with the converters.
 
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I don’t understand Canon and those new lenses....
Why they don’t give us the possibility to separate the focus distance more.... with a 3rd option for under 10/15m?!?! I don’t get it... it is a L lens nothing cheap ... this should have standard features like the Sigma 150-600 and Sony 200-600 has...
my hope was strong for a really nice Tele zoom for RF but this... isn’t what I expected! A cheap copy of an 100-400 for RF, nothing special. NOTHING to beat the current 150-600/200-600 or 200-500 lenses of the other players!!
 
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SteveC

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D = Lens Diameter (in mm)
F = Focal length
N = F-Number (or perhaps T-number to be more precise)
And we have a formula relating them:
N = F/D
The smaller N requires larger D for a given F.
There are weight and cost constraints with larger D.

You may have missed that he was asking about the short end.

If a lens is (for example) f/8 at 400 mm, that implies a 50mm entry pupil; 400/8 = 50.

So why is that lens not f/2 at 100 mm? 100/2 = 50.

One would think, at least at first, that the f number should be 4 times higher at the short end (for an actual 4 stops, not 2) for any lens with 4x zoom, yet it never is.
 
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