Canon RF 35mm f/1.8 Macro IS STM lens
Although not the perfect choice for the EOS RP, the RF 35mm f/1.8 is the only RF-mount lens so far that fits comfortably on the lighter, more compact camera body. It’s also the most affordable of the RF lenses on offer so far.
This lens is well built for its type and includes basic weatherproofing, along with shock- and vibration- resistance and its fast maximum aperture makes it worthwhile in poorly-lit situations as well as providing decent bokeh quality. The comparatively minimal design includes the features that make Canon’s RF lenses attractive: the programmable Lens Control ring and simple, easily operated controls.
Sharpness is more than acceptable at the widest aperture of f/1.8, despite some softness towards the periphery of the frame.
The RF 35mm f/1.8 Macro IS STM isn’t a true macro lens, although it does provide half life-size magnification and it’s the closest to a macro lens in Canon’s RF suite of mirrorless lenses so far. Compact and light enough to make a good partner for the EOS RP camera we tested it on, its bright f/1.8 maximum aperture is useful in dim lighting and for providing depth of field control. The STM focusing motor is almost silent, making this lens usable for recording video clips.
Angled view of the RF 35mm f/1.8 IS STM lens. (Source: Canon.)
Unlike the other two RF lenses we’ve tested, this lens lacks the ‘L’ designation that indicates superior build quality. Consequently, it also lacks the dust and moisture sealing of the other, more expensive, lenses we’ve tested.
The optical design of the RF 35mm f/1.8 lens is straightforward, with 11 elements in nine groups. One aspherical element is included for controlling spherical aberration and astigmatism, while a Super Spectra coating has been applied to individual elements to minimise ghosting and flare. A rounded nine-blade diaphragm helps ensure pleasing bokeh quality.
Built-in stabilisation provides up to five stops of camera shake correction. If Canon’s cameras had sensor-shift stabilisation, (neither the R nor the RP does) the system in the lens could work with it to provide even better compensation. However, it can work with the camera’s five-axis electronic stabilisation for greater stability when shooting movies.
The STM (stepping motor) focus drive supports fast, quiet, smooth and accurate autofocus performance that is ideal for video recording as well as still shooting. Like other RF lenses, this lens sports a configurable Control Ring that can be used to adjust a variety of exposure settings, including aperture, ISO and exposure compensation.
Who’s it For?
With the lowest price for any RF lens so far this lens is likely to be attractive to buyers of the EOS R and RP cameras. Its 63-degree angle of view is usable for landscapes, environmental portraiture and street photography, while the compact size and light weight of the lens make it ideal for travellers.
The half-life-size magnification will be disappointing for those who expected true macro capabilities (i.e. 1:1 reproduction). But it’s fine for taking close-ups of flowers and pets.
Build and Ergonomics
Build quality is very good for a lens that’s made mostly from polycarbonate plastic and the metal lens mount adds a welcome degree of solidity. It fitted very snugly onto the EOS RP body we used for our tests. “Made in Taiwan” is engraved on the lens mounting plate.
The front element of this lens is roughly 20 mm in diameter and it is recessed into the lens barrel behind a flat piece of optical glass. The 52 mm filter ring is located inside the top of the outer barrel, with the bayonet mounting for the lens hood on the outer side.
The Control Ring begins 10 mm behind the front of the lens. It’s identical to the ring on the other two lenses we’ve tested and has a textured surface and click stops to enable easy adjustments of the programmed function.
The leading edge of the focusing ring lies 3 mm behind the trailing edge of the Control Ring. This ring is 13 mm wide and entirely covered with a finely-ribbed rubber grip band. Being driven from the camera, it turns through 360 degrees when Focusing isn’t internal, which means the inner barrel lengthens as the lens moves through its focusing range. This happens when the camera is switched on and off and can catch you off-guard if you’re not aware of it.
The front element extends about 10 mm at the closest focusing distance. The ring turns full-circle when power is off and provides very little tactile feedback when the camera is powered-up.
Internal focusing is particularly useful on lenses used for close-up work as it reduces the chance that any lens movements will affect the subject lighting. It also avoids ‘spooking’ live subjects like insects. Fortunately, it’s less essential for half-life-size magnification than it would be for a true 1:1 macro lens.
Behind the focusing ring, the remainder of the lens barrel extends for just under 20 mm before sloping inwards to end in the metal lens mount. Sliders for the AF/MF selection and stabiliser (on/off) are located in this section where they are easily accessible by the left hand. No other controls or scales are provided.
The RF 35mm f/1.8 is supplied with front and end caps but neither a hood nor a soft case. The EW-52 lens hood is optionally available for approximately AU$50, while the LP1016 soft carrying pouch sells for around $40. Neither is listed in Canon’s online store.
Our Imatest tests showed the review lens to be a good performer, delivering higher than expected resolution across a wide range of aperture settings. Measurements taken in JPEG files near the centre of the frame exceeded expectations between f/2.0 and f/11. Measurements from an area towards the edge of the frame exceeded expectations between f/3.2 and f/8, indicating consistently good performance across a wide range of aperture settings.
Resolution was probably boosted to some degree by the in-camera JPEG processing, which tended to over-sharpen the files. Raw files processed with Digital Camera Professional software showed similar sharpening levels at the default settings but produced slightly lower resolution when sharpening was cut back by one step.
Diffraction began to take effect between f/8 and f/11, which is much as you would expect from a prime lens. Resolution fell sharply from f/11 on, as shown in the graph of our Imatest results below.
Because the EOS R automatically corrects chromatic aberration in JPEGs, we have used the data from CR3.RAW files to produce the graph of the results of our tests below. It shows lateral chromatic aberration well down in the ‘negligible’ band the upper edge of which is defined by the red line.
We found little or no coloured fringing in our raw file test shots and in-camera corrections completely removed it from JPEGs, as shown in the illustrations below.
The lower image is a crop from the frame above, enlarged to 100%.
We were able to disable the in-camera corrections for vignetting and distortion so we could check for these in JPEG files. We also compared them with raw files to see the extent to which each aberration could affect images.
The review lens showed serious vignetting at f/1.8, its maximum aperture. As expected, edge and corner darkening became progressively less as the aperture was stopped down, finally becoming negligible between f/3.5 and f/4.
In contrast, rectilinear distortion was virtually negligible in both JPEG and CR3.RAW files, which makes this lens a good choice for architectural photography. The ability to apply automatic corrections to these aberrations – and also correct chromatic aberration and remove the effects of diffraction both individually and together through the Digital Lens Optimiser function – make these perceived faults largely irrelevant to most potential users.
Autofocusing was generally fast and accurate; even in dim lighting after dark, there was no apparent hunting for focus. Focusing noise was negligible, even when shooting in very quiet environments, and nothing was picked up by the camera’s microphones when shooting movie clips.
Bokeh was smooth and attractive in evenly-lit situations but we found some highlight outlining in shots with bright areas in the background. Otherwise, the shallow depth of focus ensured a nice blending of tones.
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Picture angle: 63 degrees
Minimum aperture: f/22
Lens construction: 11 elements in 9 groups (including one aspherical element)
Lens mounts: EOS RF
Diaphragm Blades: 9 (circular aperture)
Focus drive: Gear type STM (stepping motor)
Stabilisation: Yes, 5 stops (Dual Sensing IS for stills and 5-axis Combination IS for movies)
Minimum focus: 17 cm
Maximum magnification: 0.5x
Filter size: 52 mm
Dimensions (Diameter x L): 62.8 x 74.4 mm
Weight: 305 grams
Standard Accessories: Lens front and end caps, EW-52 lens hood, LP1016 lens case
Distributor: Canon Australia; 1800 021 167; www.canon.com.au.
Based on JPEG files taken with the EOS RP camera.
Vignetting at f/1.8.
Bokeh at f/1.8 with an evenly-lit background; ISO 100, 1/125 second.
Bokeh at f/1.8 with an uneven background; ISO 100, 1/160 second. Note the outlining around bright highlights.
Close-up at f/2.8; ISO 125, 1/60 second. This shot was taken at the minimum focusing distance.
Close-up at ISO 100, 1/2 second at f/8.
Close-up at ISO 200, 1/15 second at f/7.1.
Flare artefacts in the form of diffuse coloured patches and reduced contrast when the camera was pointed towards the sun. ISO 100, 1/80 second at f/8.
Reduced contrast from veiling flare when a bright light source is at the left hand edge of the frame. ISO 100, 1/50 second at f/8.
ISO 100, 1/20 second at f/11.
ISO 400, 1/60 second at f/3.5.
ISO 100, 1/100 second at f/7.1.
ISO 800, 1/80 second at f/7.1.
Additional image samples can be found with our review of the EOS RP camera.
RRP: AU$749; US$499.99
- Build: 8.8
- Handling: 9.0
- Image quality: 9.0
- Versatility: 8.5