Review: Canon RF 16mm f/2.8 STM by Christopher Frost

SnowMiku

EOS 90D
Oct 4, 2020
114
82
It seems a bit silly that you can't turn off distortion correction in camera, what if people want to use that distortion for an artistic effect? They should just leave it up to the user if they want to turn the correction on or off.
 

mccasi

EOS M50
Oct 24, 2019
44
62
It seems a bit silly that you can't turn off distortion correction in camera, what if people want to use that distortion for an artistic effect? They should just leave it up to the user if they want to turn the correction on or off.
I rather always have a corrected viewfinder… like 99.999% of users. Without corrected viewfinder you cannot tell straight lines or leading lines, let alone the extreme vignetting and guessing how much of the image will be cut off when correcting.

in post I always have RAW files without correction to work with for those use cases where distortion doesn’t matter (such as Astro) or your unlikely artistic extreme distortion 3:2 use case…
 
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edoorn

EOS RP
Apr 1, 2016
356
330
It's a pretty nice and decent lens. I've actually used it on a professional assignment last week where I had to be a bit mobile; taking the adapted 16-35 III would be too much but it's easy to pop this in the bag. Client's very happy with the shots :)
 
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SwissFrank

from EOS 1N to R
Dec 9, 2018
683
377
Wasn't the RF mount supposed to allow easier engineering of better designs without these optical weaknesses?


Engineering is the business of making trade-offs. You can make one thing better by making another thing worse. In optics, you can almost always improve everything else by hurting cost or size.

In the old world of film, lens designers had to get things like distortion correct in the lens as they couldn't be easily corrected for later. And they had to often sacrifice things like sharpness in order to keep them in check.

In the digital world we can trivially correct for some lens "defects" completely, and on the fly, at nearly zero cost, and so it would be ridiculous to sacrifice size, cost, sharpness, or anything else in order to correct distortion.

The lack of a mirror allows mirrorless designs to get as close as they want to the film or sensor. In SLR lenses, that is not possible, so where some lens designs would naturally have elements where the mirror is, those designs must be compromised to allow space for the mirror. It's why the EF 35/1.4 was something like ten times the volume of the Leica M 35/1.4 despite not being appreciably better optically.

So, you're quite right that removing the need to engineer around the mirror gives the design far greater freedom, and for some lens types this means you can get better size, price, sharpness, and the like.

But it's incorrect to suggest that this freedom means that rectilinearity can or should no longer be traded off for other benefits.

In other words, the fact we can now put elements wherever we want doesn't really impact other design decisions.

I've long predicted that pretty soon all lenses will be somewhat fisheye if they're not barrel-distorted or a combination. There's simply no reason not to sacrifice distortion COMPLETELY, since it can be perfectly corrected for, if it allows other factors to be improved.
 

SwissFrank

from EOS 1N to R
Dec 9, 2018
683
377
there's still so much demand in good EF lenses, and they're optically no worse than the RF versions

The RF 50/1.2 is literally ten times sharper than the EF 50/1.2. The RF 24-105/4 has the sharpness of the EF MkII but the size of the far smaller EF MkI. And the EF version is far optically worse than the 85DS or 28-70/2 as these lenses don't even exist in EF. That's before you even look at IS, or optic quality for a given size. No Victor, you're quite wrong on this point as you seem to be on everything else.
 

Del Paso

M3 Singlestroke
CR Pro
Aug 9, 2018
1,368
1,513
No. They make some very fine and expensive lenses for the nerds who are allergic to corrections, and they make some lenses that perform nicely as an engineered system for people who want to take great pictures with a light and inexpensive lens.

Then again, those $100,000 Mercedes S-class sedans drive like crap with all the computerized traction control systems turned off. Can't Mercedes design a decent car anymore? I also hear the U.S. Air Force has some planes that won't even fly without computers ensuring stability. Talk about a step backward! Why can't they all be as smart as me and design things right?
Trouble is: these electronic corrections come at a cost, namely decrease of sharpness due to "corner stretching". But I guess this is acceptable for a $300 lens, designed mostly for street and vlogging.
As to the S Class, no!
I've been working for Daimler long enough to know that not a single Mercedes "drives like crap" , electronics switched off. You certainly lose some traction and stability advantages, but the cars remain stable even at high speeds.
i'm speaking out of experience (Stuttgart and Immendingen test tracks, cars, buses and trucks...).
There once was a real issue with the first A class generation, and, more specifically, with another German luxury car which performed miserably with ESP off. But this is another story...
 

GMCPhotographics

EOS 5D Mark IV
CR Pro
Aug 22, 2010
1,702
424
51
Uk
www.GMCPhotographics.co.uk
With a lens like this, we have to remember that our personal use cases aren't the same for everybody. As a semi-retired wedding photographer, this lens is very useful if you are running a 2 camera prime rig. With an 85/1.2 and a 35/1.4, this lens offers a quick change out for a light weight occasional super-wide. It's small, light and very pocketable. Not everyone needs a 16-35/f2.8 when they prefer a 35/1.4 as their main lens.
 

Rivermist

Mirrorless or bust.
Apr 27, 2019
106
152
Houston
Well, $300 is a pretty low cost, relatively speaking. I really do think Canon is planning on launching a sub-$800 FF EOS R, and the RP is now $1000. Having an inexpensive FF body with only costly lenses for it is not a recipe for success. But consider – the combination of the RF 16/2.8, RF 24-105 non-L, and RF 100-400 gives a user a very large focal range for a $1350 outlay.
I would also suggest along the same lines that this RF 16mm is a worthy addition to the 24-240mm all-purpose lens. Together they capture a range of focal lengths that, while not extending to 400mm, is probably still in the 95% of desirable pictures. Throw in the 600mm f:11 as a third and you have a range that is light weight, affordable and yet truly amazing.
 

GMCPhotographics

EOS 5D Mark IV
CR Pro
Aug 22, 2010
1,702
424
51
Uk
www.GMCPhotographics.co.uk
The RF 50/1.2 is literally ten times sharper than the EF 50/1.2. The RF 24-105/4 has the sharpness of the EF MkII but the size of the far smaller EF MkI. And the EF version is far optically worse than the 85DS or 28-70/2 as these lenses don't even exist in EF. That's before you even look at IS, or optic quality for a given size. No Victor, you're quite wrong on this point as you seem to be on everything else.
Yes that's pretty much the only lens. The ef 50mm f1.2 L was the most intrinsically un-sharp L prime Canon have ever made. Great Bokeh, contrast and flare resistance. Amazingly well built...but weak if wide open sharpness was your only metric. Even stopped down it never really came close to even a 24-70L at 50mm's level of sharpness. I always found the ef 50mm f1.2L's AF to be inconsistent and ponderous in low light too.
Most of the ef L primes are still very usable on the higher density sensor RF cameras. One example, the ef 400mm f2.8 LIS mk 1 is as sharp as the current mk3...it's just a LOT heavier. Another is the ef 135mm f2.0 L...still very very sharp.
Zoom wise, most of the ef mk II/III's are still very current and capable too.
Where the RF mount should excel in is with wide lenses, wider than 35mm. On the Rf mount, retro focus design isn't required because of the lack of a mirror box.
There's a lot of un-used ef lens formulas that were put on hold and reserved / modified for the RF mount. Can was planning this mount for quote a few years ahead of the EOS r1.
 
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Foxdude

EOS M6 Mark II
Aug 14, 2014
89
13
No. They make some very fine and expensive lenses for the nerds who are allergic to corrections, and they make some lenses that perform nicely as an engineered system for people who want to take great pictures with a light and inexpensive lens.

Then again, those $100,000 Mercedes S-class sedans drive like crap with all the computerized traction control systems turned off. Can't Mercedes design a decent car anymore? I also hear the U.S. Air Force has some planes that won't even fly without computers ensuring stability. Talk about a step backward! Why can't they all be as smart as me and design things right?
Very well said.
 

koenkooi

EOS 5D Mark IV
CR Pro
Feb 25, 2015
1,946
1,907
A general question as I am clueless - are distortion corrections applied to video? I'd imagine that took a lot more processing power?
Yes and yes. Every new Digic generation has allowed more DLO to be done in video, with Digic X you get everything minus diffraction correction, if I remember correctly.
 
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Oct 27, 2020
2
0
Since Canon specifically mentioned astrophotography as a use case for this lens, I may have had to high expectations about how well this would do in this arena vs e.g. Rokino 14mm f2.8 .

But considering image quality reports so far, and the challenges with by wire focus in astrophotography, I think I will end up skipping this one.
 

peters

EOS RP
Dec 25, 2017
510
498
Wasn't the RF mount supposed to allow easier engineering of better designs without these optical weaknesses? Watching this review, the way the focus sounds like the original nifty fifty... It feels like they just slapped this together for lowest possible cost.
Jeah, well, but it IS a lense at the lowest possible cost? Especialy at this quite good quality at this price point and small size? :)
 

SwissFrank

from EOS 1N to R
Dec 9, 2018
683
377
Trouble is: these electronic corrections come at a cost, namely decrease of sharpness due to "corner stretching". But I guess this is acceptable for a $300 lens, designed mostly for street and vlogging.
This line of reasoning is moronic, given that, as I already explained, correction of distortion results in destination pixel being AT WORST the average of two source pixels (linearly), and this very forum is full of pros ranting that 22MP is indeed enough for professional work. And again, the review shows the corners are far less sharp than that.

It's a waste of my time to make me write the same explanation over and over. Just read what I wrote the first time and learn from it and stop making me repost and repost.

As to Mercedes driving like crap, suffice to say I recall an esteemed automotive journalist writing, that Mercedes must tire of delivering a car it thinks measures up, upon which BMW releases a model that not so much moves the goalposts but chucks them over the horizon. My 2000 M5 is still driving like new and handling great and resale value is a high multiple of any contemporary Mercedes.
 
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Del Paso

M3 Singlestroke
CR Pro
Aug 9, 2018
1,368
1,513
This line of reasoning is moronic, given that, as I already explained, correction of distortion results in destination pixel being AT WORST the average of two source pixels (linearly), and this very forum is full of pros ranting that 22MP is indeed enough for professional work. And again, the review shows the corners are far less sharp than that.

It's a waste of my time to make me write the same explanation over and over. Just read what I wrote the first time and learn from it and stop making me repost and repost.

As to Mercedes driving like crap, suffice to say I recall an esteemed automotive journalist writing, that Mercedes must tire of delivering a car it thinks measures up, upon which BMW releases a model that not so much moves the goalposts but chucks them over the horizon. My 2000 M5 is still driving like new and handling great and resale value is a high multiple of any contemporary Mercedes.
1: I'd suggest you take a look at TDP...
2: If you think you're THE authority...
3: Fine if you prefer BMW, and believe MB customers to be idiots, I just don't care.
4: No need to be insulting
 

koenkooi

EOS 5D Mark IV
CR Pro
Feb 25, 2015
1,946
1,907
Cool, thanks!
I've checked the R5 manual at https://cam.start.canon/fa/C003/manual/html/UG-03_Shooting-1_0190.html:
Schermafbeelding 2021-10-27 om 15.58.53.png
 

juststeve

EOS M6 Mark II
Nov 29, 2018
73
109
For those doubting focus by wire with the 16/2.8, perhaps autofocus will work.

With my R5 I can autofocus on many stars with my 20/1.4 Sigma, 35/1.4 Tamron, 70-200/2.8 L IS, and my 31 year old 300/2.8 L. One needs to find a reasonably good star well above the horizon and it is a good idea to turn the lens to manual focusing once accurate auto focus has been achieved. I have accidentally pressed the focus button while astro photography was going on and had to start over again. Also, my M6 ii will autofocus the 22/2 on night skies.