Canon Business General

Here is the official Canon EOS R system white paper

Canon has released a whole bunch of resources alongside the new Canon EOS R system. One of the more interesting reads, if you’re into the technical stuff, is the official Canon EOS R system white paper.

The white paper also discusses the technical limitations of EF and why the RF lens mount is a positive step forward for creators. Along with a ton of information about the four RF mount lenses announced today.

You can download the official Canon EOS R white paper from Canon directly here.

Apr 23, 2018
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#3
excellent white paper, especially as far as lens data goes. Have not seen Canon themselves so openly compare new lenses vs. previous ones - clearly spelling out strength and weaknesses.

Also interesting is the part on new "Thin-type" nano USM on RF 24-105. :)
 

neuroanatomist

Spends too much time on this forum
Jul 21, 2010
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#4
There's no direct, mechanical connection at all to the group(s) of elements that move the focusing element. Rotating the focus ring sends a series of very specific, fine signals to these contacts. These are converted into signals to the same focus motor (USM, Nano USM, etc.) that's used for autofocus.
RF lenses – even the L-series USM lenses – are all focus-by-wire. Ugh.
 
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neuroanatomist

Spends too much time on this forum
Jul 21, 2010
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#7
Briefly what negatives come with this - I assume some positives??
Negatives are lack of tactile feedback, no hard stop at infinity or the MFD (for macro and astro, its common to just set to one end of the focal range), and that the lens needs to be mounted to a powered-on body to change the focus. The last one really only matters with lenses where the front element extends with focusing (like the 85L), where you have to remember to retract the front element before unmounting the lens. I don’t know of the RF 50/1.2L has an extending front element, but the focusing group comprises the front 2/3 of the elements (the front 11 of 15 elements).

Positives are that you can change the direction of focus (presumably via a camera setting), not sure why you’d want to.

Mixed is the focus throw can be variable (it is on STM lenses, I presume it will be/can be for RF lenses). I’ll just copy this bit from my review of the M18-150: With a fast manual rotation speed, the focus ring must be rotated 150° to rack the lens through the full focusing range, while a slow rotation speed requires a rotation of 240° to cover the same range. The idea behind this is to allow faster manual focusing with a shorter focus throw when moving between close and distant subjects, while also allowing precise fine-tuning of manual focus with a longer focus throw. I call it mixed because while it sounds nice in theory, in practice some find it annoying and difficult to get used to.
 

BeenThere

EOS Rebel T7i
Sep 4, 2012
739
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#8
Negatives are lack of tactile feedback, no hard stop at infinity or the MFD (for macro and astro, its common to just set to one end of the focal range), and that the lens needs to be mounted to a powered-on body to change the focus. The last one really only matters with lenses where the front element extends with focusing (like the 85L), where you have to remember to retract the front element before unmounting the lens. I don’t know of the RF 50/1.2L has an extending front element, but the focusing group comprises the front 2/3 of the elements (the front 11 of 15 elements).
If you depend on the lens physical stop to set infinity focus, you usually miss sharp focus slightly.
 

ahsanford

Particular Member
Aug 16, 2012
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466
#11
RF 50 f/1.2L USM = Ring USM, but it still could be FBW (there are some ring USM EF lenses that are FBW).

The 28-70 f/2 USM does not state what type of USM it has.

- A
 

Mark D5 TEAM II

Proud N0ink 0wnz0r / crApple iFruitcake H4t3r
Mar 5, 2013
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Tleilax, Thalim Star System
#12
Just read through the 43 pages, and, based on the MTF, the 28-70/2 at f/2 is sharper than both 24-70/2.8 & 24-70/4 at both ends of the zoom, the RF 50/1.2 is waaayyy sharper than the EF 50/1.2 and 50/1.8, the RF 24-105/4 is slightly worse in some parts of the frame than the EF 24-105/4 Mk.II, and roughly equal to the 24-105/3.5-5.6 in others. The RF 35/1.8 IS Macro is slightly worse than the EF 35/1.4L but better than EF 35/2 IS USM overall.
 

ahsanford

Particular Member
Aug 16, 2012
7,941
466
#13
RF lenses – even the L-series USM lenses – are all focus-by-wire. Ugh.

Neuro, is this confirmed? Jordan Drake from DPR said the same at the event last night but I could only confirm it (of the three USM lesnses coming) in this document for the RF 24-105.

- A
 

neuroanatomist

Spends too much time on this forum
Jul 21, 2010
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#16
Neuro, is this confirmed? Jordan Drake from DPR said the same at the event last night but I could only confirm it (of the three USM lesnses coming) in this document for the RF 24-105.
I haven’t confirmed it for the other RF lenses, but the new EF 400/2.8 III and 600/4 III are both FBW. I use MF on my 600 II frequently, and not that I planned on getting the MkIII, but FBW pretty much nails that coffin shut.
 
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Kit.

EOS Rebel SL2
Apr 25, 2011
507
138
#17
RF 50 f/1.2L USM = Ring USM, but it still could be FBW (there are some ring USM EF lenses that are FBW).

The 28-70 f/2 USM does not state what type of USM it has.
If it is ring USM and can be commanded from the body to change the sensitivity (and even direction) of the focusing ring, it must be FBW.
 
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Jan 6, 2013
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3
#18
A very useful explanation of their new tech, as well as MTF details for the lenses. Even though the 24-105 is shown in some areas to be a bit worse than the EF model, when I can afford it I may well get the kit. It will be a while though! £3k plus, and then probably a post-Brexit premium :(

The focus-by-wire? I guess we will have to see how well it works in practice.
 
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scyrene

EOS 6D Mark II
Dec 4, 2013
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#20
you have to remember to retract the front element before unmounting the lens. I don’t know of the RF 50/1.2L has an extending front element, but the focusing group comprises the front 2/3 of the elements (the front 11 of 15 elements).
According to DPR, all the lenses are internally focusing except the 24-105 which is 'rear' (not sure what that means - it extends into the body maybe?), I wonder if this is why?
 
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