Canon RF 15-30mm f/4.5-6.3 IS STM lens
The RF 15-30mm f/4.5-6.3 IS STM lens is modestly priced and makes a good companion to Canon’s RF 24-105mm f/4-7.1 IS STM lens, which is often provided as the kit lens in a camera+lens bundle. It would also be good to use with the RF 24-105mm f/4 L IS USM lens.
This lens is sure to find a spot in the camera bags of real estate photographers and solo vloggers who use Canon’s full-frame EOS R cameras.
It would also be worth considering by bushwalkers with weather-resistant camera bags, especially those who enjoy shooting landscapes or like taking the occasional video.
Announced on 12 July, the Canon RF 15-30mm f/4.5-6.3 IS STM lens provides an affordable ultra-wide angle zoom lens for everyday photographers who want to extend the range of subjects they can capture. A great complement to the RF 24-105mm f/4-7.1 IS STM kit lens and similar in size and weight, it is ideal for travellers who enjoy photographing landscapes, cityscapes and interiors and appreciate the value of effective stabilisation for shooting flexibility in low-light conditions.
Angled view of the RF 15-30mm f/4.5-6.3 IS STM lens. (Source: Canon.)
It’s worth noting that this lens is NOT supplied with a lens hood, a significant omission for a lens of this type. The EW 73E hood is available in most stores selling this lens, priced at between AU$50 and $60. Since it probably contains only a few cents’ worth of plastic, we think it should have been bundled with the lens.
The optical design of this lens consists of 13 elements in 11 groups and includes two UD (ultra-low dispersion) elements and one aspherical element. Canon’s multi layer Super Spectra Coating (SSC) has been applied to suppress ghosting and flare and ensure consistent colour reproduction and sharp details.
It has a seven-bladed iris diaphragm that creates a circular aperture. Built-in image stabilisation claims up to 5.5 stops of shake correction or seven stops of Coordinated IS when the lens is used on a camera with in-body image stabilisation, like the EOS R6 II we used for our tests.
Autofocusing is driven by a stepping motor, which is quiet enough to enable it to be used for shooting video. The minimum focus is 13 cm when the lens is focused manually or 28 cm when it is used in AF mode, where reproduction is roughly half life-size at the 30mm focal length.
Who’s it For?
Lightweight and easy to carry as well as reasonably affordably priced, this lens is targeted mainly at everyday photographers, rather than professional users. It also covers ideal focal lengths for solo vloggers, who also benefit from the quiet STM AF system.
On cameras with full-frame sensors it covers a very wide angle of view at the 15mm focal length. This will suit photographers who enjoy taking pictures of expansive landscapes as well as architectural photographers – particularly those who shoot real estate and need to take shots of interiors that are often cramped as well as exterior shots.
This lens is not particularly fast – a consequence of its design, which prioritises light weight and a relatively compact size. Maximum and minimum aperture changes as the focal length is adjusted are shown in the table below.
Unfortunately, despite plenty of scope for stopping down to gain depth of field, the widest angles of view aren’t much good for panoramic merging because of their inherent angular distortion. We’ve provided a couple of examples below to show how much subsequent ‘Transform’ adjusting would be needed to create an image that can near to replicating the actual subject.
The two source images.
The initial result of merging them with the Photomerge tool in Photoshop.
The 30mm focal length, while still classed as ‘wide angle’, could be used for panorama sequence capture. However, the merged frames would still require tweaking to produce realistic results.
It’s worth noting this lens can also be used on cropped-sensor cameras like the EOS R7 and R10, where it will cover the same angles of view as a 24-48mm lens on a 35mm camera. However, because it isn’t weather-resistant it shouldn’t be used in potentially damaging conditions.
Build and Ergonomics
Canon doesn’t specify which materials this lens is made from but it appears to be mainly plastic – although the mounting plate is definitely made from metal of some kind. Non-functional sections of the outer barrel are smartly finished in matte black and assembled with tight tolerances. However, this lens is not weather sealed and no dust- and moisture-repelling coatings have been applied to the front and rear elements to reduce the need for frequent cleaning.
The front element is approximately 35 mm in diameter and bulges noticeably outwards. It’s set back into the inner barrel and surrounded by a 15 mm wide annulus that is ridged for most of its inner edge and surrounded by vertical threading that accepts 67 mm diameter screw-in filters.
The outer edge of the filter ring has a shallow bayonet fitting for the lens hood – which isn’t supplied. The inner barrel extends by about 10mm when the lens is zoomed from 30mm to 15mm.
At the front of the outer barrel is the control ring, which is approximately 12 mm wide and is mostly covered with a dimpled grip band. This ring is used for manual focusing when the camera is in manual focus mode and the switch towards the rear of the lens is set to the Focus position. In this mode, it turns smoothly.
Setting it to the Control position allows the ring to be used for adjusting a selected function (aperture, shutter speed or exposure compensation) that is programmed via the camera’s menu. Click stops are automatically engaged in this position.
Immediately behind the Focus/Control ring is the zoom ring, which is 40 mm wide and mostly clad in rubber ridging. The inner barrel extends by roughly 8 mm when the lens is at the 15mm but pulls back as the focal length is extended to 30mm.
An un-ridged band around the rear edge of this ring carries focal length settings for 15mm, 20mm, 24mm and 28-30mm focal lengths. These line up against a short white line on the fixed section of the barrel between the zoom ring and the mounting plate.
This section of the barrel is 31 mm wide and carries low-profile slider switches for Focus/Control ring settings and switching stabilisation on and off. The barrel steps in by a millimetre or so and changes to a grey metal with a red index mark for attaching the lens to a camera.
The mounting plate is chromed metal but there’s no rubber gasket around it to keep out moisture and dust. Inside the mount are 12 gold-plated contacts for passing signals between the lens and the camera body. The rear element of the lens is very close to the actual mount so care will be required to prevent it from being damaged or contaminated by dirt of grease when changing lenses.
Our Imatest tests showed the review lens to be very competent for its type, with measured resolution in the centre of the frame in JPEG files falling a little below expectations at the 24mm focal length with an aperture of f/5.6. CR3.RAW files recorded simultaneously produced resolutions well in excess of expectations for the review camera’s 24-megapixel sensor.
As anticipated, resolution declined towards the edges of the frame for both JPEG and raw files, although not quite to the degree we had expected. The graph below shows the results of our tests for JPEG files across the main focal length and aperture settings.
Because the EOS R6 II camera provides internal corrections for JPEGs, our lateral chromatic aberration measurements are based on CR3.RAW files with optical corrections disabled in Adobe Camera Raw. In the graph of our test results below, which shows this aberration to be largely irrelevant, the vertical red line marks the boundary between ‘negligible’ and ‘low’ CA.
Like chromatic aberration, vignetting and rectilinear distortion had to be assessed through raw files with all optical and profile corrections disabled in Adobe Camera Raw. Both were quite extreme at the wider angles of view, but much less so by the 30mm focal length and neither has practical relevance since they are effectively addressed with automatic in-camera correction for JPEGs and adjustments most raw file converters.
Test shots showed the review lens to be very flare-resistant, which is surprising since it is supplied without a lens hood. Even when the sun was inside the frame, we found very little loss of contrast and colour saturation in the shots we took, especially with raw files.
The seven-bladed iris diaphragm produced 14-pointed sunstars when the lens was stopped down to its minimum aperture. However, the resulting images were softened a little as a result of diffraction and the wide angles of view meant they were relatively small within the frame.
Bokeh was much as we expected from an ultra-wide, relatively slow zoom lens since it’s difficult to blur the background satisfactorily at the minimum focus distance with wide angle of view. But few photographers would consider using this lens for close-ups with a shallow depth of field when better alternatives exist.
Autofocusing was generally fast and accurate with most types of subjects in different lighting conditions and able to adjust quickly as conditions changed. It was also very quiet, thanks to the stepping motor drive. Focus breathing was detected at a relatively modest level.
Although stabilisation is seldom needed in ultra-wide angle lenses, this lens benefits from excellent built-in OIS, which can work with the in-camera stabilisation in the EOS R6 II camera we used for our tests. We found no instances of camera shake affecting any of our test shots.
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Picture angle: 110 degrees 30 minutes to 71 degrees 35 minutes
Minimum aperture: f/22-32
Lens construction: 13 elements in 11 groups (including 2 ED and one aspherical elements plus Super Spectra Coating)
Lens mounts: Canon RF
Diaphragm Blades: 7 (rounded aperture)
Weather resistance: no
Focus drive: Stepping motor
Stabilisation: Yes 5.5 stops CIPA rating (7 stops with in-camera IS)
Minimum focus: 13 cm in manual focus or 28 cm with AF operation
Maximum magnification: 0.52x
Filter size: 67 mm
Dimensions (Diameter x L): 76.6 x 88.4 mm
Weight: 390 grams
Standard Accessories: Front and end caps
Distributor: Canon Australia; 1800 021 167
Based upon JPEG files taken with the Canon EOS R6 II camera.
Based on CR3.RAW files recorded with the same settings and converted into 16-bit TIFF format with Adobe Camera Raw.
Vignetting at 15mm f/4.5.
Vignetting at 20mm f/5.0.
Vignetting at 24mm f/5.6.
Vignetting at 30mm f/6.3.
Rectilinear distortion at 15mm.
Rectilinear distortion at 20mm.
Rectilinear distortion at 24mm.
Rectilinear distortion at 30mm.
15mm focal length, ISO 100, 1/125 second at f/8.
20mm focal length, ISO 100, 1/125 second at f/8.
24mm focal length, ISO 100, 1/125 second at f/8.
30mm focal length, ISO 100, 1/100 second at f/8.
Close-up at 15mm f/4.5; ISO 100. 1/320 second.
Close-up at 20mm f/5.0; ISO 100. 1/200 second.
Close-up at 24mm f/5.6; ISO 100. 1/160 second.
Close-up at 30mm f/6.3; ISO 100. 1/125 second.
Close-up at 15mm f/6.3; ISO 200. 1/6 second.
Sunstar at 15mm f/22; ISO 100. 1/100 second.
Sunstars at 30mm f/32; ISO 100. 1/13 second.
Real estate exterior shot; 30mm focal length, ISO 100. 1/200 second at f/9.
Real estate interior shot; 15mm focal length, ISO 160. 1/4 second at f/8.
15mm focal length, ISO 100. 1/125 second at f/16.
Contre-jour shot at 15mm focal length, ISO 100. 1/800 second at f/10.
Flare resistance; 15mm focal length, ISO 100. 1/320 second at f/9.
15mm focal length, ISO 100. 1/60 second at f/10.
30mm focal length, ISO 100. 1/60 second at f/10.
18mm focal length, ISO 100. 1/500 second at f/8.
15mm focal length, ISO 100. 1/125 second at f/11.
20mm focal length, ISO 100. 1/40 second at f/8.
RRP: AU$969; US$549.99
- Build: 8.9
- Handling: 9.0
- Image quality: 8.9
- Autofocusing: 8.9
- Versatility: 8.5