The Canon RF 135mm f/1.8L USM is coming in Q4 of 2022 [CR3]

jonbenz

Canon EOS 6D/70D
May 31, 2018
8
2
I need a 135mm f/1.0DS.

It's not an impossible ask. The resulting front element size of about 140mm is the same as the Nikon 300/2, or Canon 400/2.8, 600/4., 800/5.6. These lenses are pricey but not unaffordable.

The ability isn't that crazy either. Wide-open lenses have football-shaped highlights in the corners and a related substantial light fall-off. Stop down to f/1.4, though, and you could have a circular highlight from center to corner. Then, add a DS filter and light transmission and total amount of bokeh is again cut in half, to the equivalent of f/2.0.

But while the bokeh amount is the equivalent of f/2.0, it is spread in diffuse balls of light no matter where in the frame an out-of-focus highlight is. The result would be the most beautiful portrait lens of all time. Its photos would be recognized by all, its edgeless, circular highlights even in the corners unproducible with any other lens.

This is what I'd call a "halo lens," much like the EF 1200mm/5.6, or the tilt-shift lenses, that people who don't own Canon can recognize the work of instantly and yearn to have even the theoretical possibility of shooting. Other examples would be a 50/0.7, similar to the half-dozen or so examples used by Stanley Kubrick to shoot Barry Lyndon.
Hey Frank, would you share how to calculate the resulting front element size? I have read it a lot on the forum and I would like to know the math behind it. Thanks!
 

neuroanatomist

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Jul 21, 2010
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Hey Frank, would you share how to calculate the resulting front element size? I have read it a lot on the forum and I would like to know the math behind it. Thanks!
A lens’ entrance pupil diameter is the apparent view of the iris diaphragm as seen from the front of the lens. The front element of a lens must be of sufficient diameter to ‘fill’ the entrance pupil with light. For telephoto lens designs, the axial position of the entrance pupil is approximately at the position of the front element. So to estimate the size of a telephoto front element, you simply divide the focal length by the maximum f/number (because f/number is the ratio of focal length to entrance pupil diameter).

Thus, a 135mm f/1 would need a 135/1 = 135mm front element. Similarly, the 600mm f/4 would need a 150mm front element. In practice, lens specs are rounded, and usually in a direction that benefits the manufacturer. So, the 600/4 is probably something like a 593mm f/4.12 lens, which is consistent with the ~144mm diameter that I actually get with a measuring tape on my 600/4L IS II.

Note that the entrance pupil being at the axial position of the front element is a telephoto design ‘feature’. Thus, for example, the front element of the 16mm f/2.8 is much larger than 5.7mm.
 
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Jethro

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Jul 14, 2018
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Note that the entrance pupil being at the axial position of the front element is a telephoto design ‘feature’. Thus, for example, the front element of the 16mm f/2.8 is much larger than 5.7mm.
A 'telephoto' lens being >85mm?
 

neuroanatomist

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A 'telephoto' lens being >85mm?
Sort of. A telephoto design is one where the physical length of the lens is shorter than the focal length. For example, the EF 100mm f/2 is a telephoto design – it’s about 74mm long. However, the EF 100mm f/2.8 Macro lenses are around 120mm long and thus are not telephoto designs.
 
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Ozarker

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Seems I’m in the minority, but I’m disappointed this will be f1.8. The lens roadmap has been mostly accurate to date and I’ve been excitedly waiting -- for what feels like years now -- for a 135mm f1.4.

Sigma, Sony and Samyang already make excellent 135 f1.8s and I can’t see this Canon lens being much better. Making yet another 135mm f1.8 just seems to lack ambition. Sure, it will fill a gap in the RF system, but Canon had a real opportunity here to make an “ultimate portrait lens” which could have attracted people from other systems.

If Canon weren’t so hostile to 3rd party manufacturers then I’m sure Sigma/Samyang could have provided an excellent/affordable RF 135mm option, leaving Canon to focus on something that would have pushed the envelope. I had thought that the RF 28-70 f2 was a statement of intent from Canon that they planned to make more unique and ambitious lens designs, but sadly that lens appears to be a one-off.

I sincerely hope the RF 35L doesn’t disappoint.
I would also like to see f/1.4... but I don't see how a small difference (f/1.4 vs f/1.8) would be earthshaking enough to get folks to abandon other systems. At that focal length, in my opinion, a difference like that won't be noticed. My desire for faster would be, just because. Besides, f/1.8 would probably be a much more affordable and convenient size for the masses.
 
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Jan 22, 2021
3
4
Aaa 35mm 1.2 would be an instant buy for me (if reasonably sized). I wonder if we see answer to Nikon teles for birding, where it's cheaper to get the lens with Z9 body then just a Canon lens.
 
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jonbenz

Canon EOS 6D/70D
May 31, 2018
8
2
A lens’ entrance pupil diameter is the apparent view of the iris diaphragm as seen from the front of the lens. The front element of a lens must be of sufficient diameter to ‘fill’ the entrance pupil with light. For telephoto lens designs, the axial position of the entrance pupil is approximately at the position of the front element. So to estimate the size of a telephoto front element, you simply divide the focal length by the maximum f/number (because f/number is the ratio of focal length to entrance pupil diameter).

Thus, a 135mm f/1 would need a 135/1 = 135mm front element. Similarly, the 600mm f/4 would need a 150mm front element. In practice, lens specs are rounded, and usually in a direction that benefits the manufacturer. So, the 600/4 is probably something like a 593mm f/4.12 lens, which is consistent with the ~144mm diameter that I actually get with a measuring tape on my 600/4L IS II.

Note that the entrance pupil being at the axial position of the front element is a telephoto design ‘feature’. Thus, for example, the front element of the 16mm f/2.8 is much larger than 5.7mm.
Thanks, great explanation!
what about normal lenses? let's say, how would they calculate the dream lens front element? (50mm f0.95).
 

neuroanatomist

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Thanks, great explanation!
what about normal lenses? let's say, how would they calculate the dream lens front element? (50mm f0.95).
‘Normal’ focal length lens designs are often relatively symmetrical, such that the entrance and exit pupils are very close to each other and near the physical iris diaphragm. That’s true for both the older double gauss designs like the EF 50/1.2 and the newer, more complicated designs like the RF 50/1.2.

64C6FA5E-5E66-490C-AF66-B6C22303C4F4.jpeg

The front element size is mainly determined by the degree to which designers want to reduce aberrations.
 
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fox40phil

5DIV & RP
Apr 12, 2013
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www.phileas-schoenberg.de
Since my R6 I m at a really bad state with my old lenses... they perform really bad in "fps" with the R6 and the mechanical shutter.
With the MK1 70-200 2.8 non-IS i only get 5-9fps with AI Servo on. Same with the 135 2.0!
This sucks :(.... Especially for indoor sports with balls (table tennis, socker etc), because of the rolling shutter with electronic shutter!
 

SwissFrank

1N 1V 1Ds I II III R R5
Dec 9, 2018
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would you share how to calculate the resulting front element size?
Sure John.

fstop = focal length / aperture (the bright circle you see if you take the back cap off the lens and hold it up to a white wall).

So a 85/1.2 lens has literally an 85mm divided by 1.2 hole for light to go in. Remember camera lens specs aren't exact, so this is basically 72mm. So is 135/2 or 200/2.8.

The front element can be a lot bigger than this though, especially on wide angles. A 14-35/4 might have a 77mm front filter size and front element but the aperture is only 14mm/4=3.5mm big even wide open.
 
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May 9, 2022
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With the 200MM F2 discontinued it would be nice to have a 135mm with epic shallow DOF as a replacement. 1.8 is not going to get me there.
 
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SwissFrank

1N 1V 1Ds I II III R R5
Dec 9, 2018
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430
With the 200MM F2 discontinued it would be nice to have a 135mm with epic shallow DOF as a replacement. 1.8 is not going to get me there.
Yes, a 135/1.4's center 70% (linearly) or half (by area) would look exactly like a 200/2, if we assume both lenses were perfect implementations of their spec. But it would be, critically, wider. And with today's 45MP cameras, you could just crop a 135/1.4 to 200mm field of view and still have a very sharp 22MP image.

I'm personally hoping for a 135/1, that has perfectly round highlights in the corners by 1.4, and with a DS filter cutting transmission and DOF to f/2, but instead of hard-edged disks, it has fuzzy balls of about twice the size (by area). It'd be the ultimate portrait lens I think.
 
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Oct 24, 2018
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Finland
I'm personally hoping for a 135/1, that has perfectly round highlights in the corners by 1.4, and with a DS filter cutting transmission and DOF to f/2, but instead of hard-edged disks, it has fuzzy balls of about twice the size (by area). It'd be the ultimate portrait lens I think.
How many people can afford 7K lens :D ? And probably no wife allows to buy such lens. You better start living in celibacy :D
 

GMCPhotographics

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Aug 22, 2010
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??? What are the deficiencies?
The deficiencies are not optical or anything specific about it's build. It's more to do with what if offers a photographer in terms of low light capability. I shoot a lot of weddings and compared to a 85mm f1.2, the 135L looses 2.3 stops in real world exposure settings. The 85mm is 1.3 stops brighter, the focal length allows for a faster shooting speed, 1/80th sec vs 150th sec. These add up and make the lens a lot less useful in low light situations. For moments inside a dimly lit English church (I once shot a wedding service in Canterbury Cathedral crypt by candle light), I wouldn't use a 135L. It's just not "fast" enough. Out side under normal (English) daylight it's fine. A 70-200 f2.8 LIS looses one stop in brightness to the 135mm, and should be shooting at 1/200th sec for sharpness. But it has a 4 stop IS unit...which helps bring the shutter speed down and the ISO values with it. The 135L doesn't come close to the low light abilities of either the 85 f1.2 or 70-200 f2.8 LIS.
One of the issues a wedding photographer has is consolidating their lens list to the barest minimum.
If the 135mm was roughly the same size and weight (which is one of it's key benefits - it's an awesome walk about tele lens) but gained a 4 or 5 stop IS unit...it would be even more versatile. If it gets heavier and larger, like pushing the aperture value / objective lens size to accommodate f1.8 then the lens becomes too heavy and burdensome compared to the current model. For weddings, the 135L is super discrete for shy guests. It's half the size of the big shouty white 70-200 and it's also half the weight, which is a lot easier to handle all day.
 
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