Canon RF 16mm f/2.8 STM
- The CanonRF 16mm f/2.8 STM is a prime lens for Full Frame (FF) format, compatible with Canon EOS R FF and APS-C mirrorless cameras.
- This lens is available exclusively in the Canon RF mount.
- The lens is filterable with 43mm filters, there is not the image stabilization and the focus takes place via AF Motor (Stepper Motor STM).
- The lens is in production (since 2021 - today).
- Price range*: $
- Equivalences**: a 16mm f/2,8 mounted on a Full Frame camera will remain so, mounted on a Canon APS-C camera it will have a field of view, a Depth of Field and a "out of focus portion" of the image roughly equivalent to that of a 26mm f/4,5 lens on Full Frame.
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*Price range - legend: $: <400$ | $$: 400$ - 1000$ | $$$: 1000$ - 2000$ | $$$$: +2000$
**Equivalences - explanation: the concepts of "equivalent focal length" and "equivalent aperture" were born with the aim of allowing similar photos to be taken (in terms of framing and Depth of Field) with two cameras with sensors of different sizes without changing the distance from the subject (otherwise the perspective would also change) and placing the Full Frame format as a reference in the equivalence. The "equivalent focal length" helps the photographer to understand what field of view it will have (i.e. what the lens + camera combination can see and capture) and consequently what is the equivalent angle of view. The "equivalent aperture" helps the photographer to understand the equivalent Depth of Field (DoF) and how much "out of focus portion" the image will have. The equivalent "mm" are obtained by multiplying the focal length by the crop factor of the camera used [CANON APS-C: 1.62x] and in a similar way the equivalent "f/" aperture is calculated. It is important to remember that a lens NEVER changes its physical characteristics, a 16mm f/2.8 always remains a 16mm f/2.8, regardless of whether it is mounted on Full Frame, APS-C, Medium Format and so on. ONLY the field of view changes. Exposure is also independent of the sensor format, so regardless of the sensor format of the camera on which the lens is mounted (as long as the lens can be mounted on multiple formats), with the same aperture, the shutter speed and ISO will also be the same.
Specifications
COMPATIBLE MOUNT
Canon RF
Focal length | Angle of view
16mm | 108°
Format
FF
Maximum aperture | Minimum aperture
f/2.8 | f/22
Aperture
7 blades
Minimum focusing distance
0,13 m (5.1″)
Maximum magnification | Reproduction Ratio
0,26x | RR 1:3,8
Image stabilizer
No
Focus
AF Motor (Stepper Motor STM)
Filter diameter
Ø43mm
Optical construction
9 elements in 7 groups
Type
Prime lens
Weather sealing
No
Lens hood
Sold separately
Tripod ring
No
Extenders
Not supported
Weight | Dimensions (diameter x length)
0.36 lb | Ø2.7″ x 1.6″
Other features
- Dual-function Manual Focus ring / Control ring (no Clicks), there is a dedicated switch on the lens barrel to switch between functions (FOCUS-CONTROL). The control ring, if it actived, it can be customized to quickly change: Shutter speed | Lens aperture | ISO | Exposure compensation| and more
- The distance scale is available in EVF or Live View LCD screen of compatible EOS R-series cameras
- Full-time manual focus: the lens can be focused manually even when in autofocus (AF) mode [Manual focus via a focus-by-wire system, to work the camera must be turned on]. Remember to activate the "Electronic full-time MF" setting from the camera menu to have full-time manual focus in addition to One-Shot AF and AI Servo AF (in this case, decouple the autofocus from the shutter button and assign it, for example, to the "AF-ON" button; otherwise, as soon as you press the shutter button, the focus returns to automatic, making manual focus correction unnecessary). However for older cameras (R; Ra; RP) and entry level (R100) there is no such setting and the "Lens electronic MF" setting must be activated from the camera menu, but the full-time manual focus is only available in One-Shot AF and after half-pressing the shutter button (if you also want it in AI-Servo it is possible to get around the limitation with various solutions by acting on the settings available on the camera, such as: 1] The use of the "Back-Button Focus" [e.g. AF-ON] by decoupling the AF from the shutter button, thus simply rotating the focus ring to have manual focus in any AF operating mode 2] Program a button for AF-OFF, i.e. the automatic focus lock, keep it pressed and rotate the focus ring to do manual focus 3] Program a button for a quick switch from AI-Servo AF to One-Shot AF 4] If it is physically present, temporarily set the lens selector to MF)
MTF chart
The MTF (Modulation Transfer Function) chart is useful for having an objective representation of the contrast and resolution of a lens from the center to the edges compared to an ideal system. Click on the link to view it:
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(remember that the MTF curves are calculated at full aperture, by closing the aperture basically all lenses are fine)
Video-reviews and Reviews
For obvious reasons this is just a selection of the main and most significant video reviews and reviews available online for the Canon RF 16mm f/2.8 STM.
If you are interested in this lens, I invite you to find out more by reading the reviews in full / watching the video reviews on the websites / YouTube channels of the respective creators linked here:
Review 1
(Accurate and complete review of the Canon RF 16mm f/2.8 STM, with numerous product photos and with the possibility of comparison with other similar lenses)
Review 2
(In-depth and well-structured analysis with many samples of the Canon RF 16mm f/2.8 STM)
Review 3
(Detailed, well-structured and technical analysis, with sample photos, of the Canon RF 16mm f/2.8 STM)
Review 4
(Well-structured and technical analysis, with samples, even at full resolution, of the Canon RF 16mm f/2.8 STM)
Notes:
- Always view / read reviews with a critical attitude, remembering that the various evaluations must be parameterized with each other by the date the lens was tested and with which camera the lens was reviewed. A 20-year-old lens considered excellent on today's dense sensors will probably still be very good, but it is equally likely that in terms of contrast and resolution it has now been surpassed by more modern lenses.
- Reviews, although really useful for getting a general idea of a lens without ever having tried it directly, are not an exact science. If you just look at the numbers and the negatives there are some lenses that with all their flaws appear to be pure rubbish. Some are actually really poor, but for others there may be precise design choices behind them to obtain a certain rendering of the blur or performance / size ratio otherwise impossible to have if the lens were perfectly corrected for vignetting, distortion, Chromatic Aberration, Spherical Aberration, astigmatism and so on.
- The good intention is to keep all the links working, but if that is not the case I thank those who will report the broken ones. Everything on the web is by its nature not lasting. Modifications and deletions of contents are not rare and especially for the older lenses, a lot of history is being lost. Thanks for the collaboration! :)
PROS and CONS
Brief summary of the main PROS (✅) and the related CONS (❌) for the Canon RF 16mm f/2.8 STM highlighted in the various video-reviews and online reviews:
✅ PROS
Very good overall image quality, especially in the center, compact sizes, with a quick and quiet autofocus motor
❌ CONS
Weak edges on Full-Frame, focus breathing (for video use), coma (e.g. to be considered if you do astrophotography), vignetting*, CA (Chromatic Aberration)*
(the lens, if used without the software corrections applied, at 16mm is more wide angle than declared and this would be an advantage, however in photo the distortion is exaggerated)
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*Important note: most mirrorless lenses are designed to be "helped" via software with "lens corrections" (applicable directly in the camera and/or post-production software, e.g. Adobe Lightroom), it is not really a cons, but it's good to know. The function completely corrects or, if it is not possible, only partially: vignetting, distortion, CA (Chromatic Aberration), ...