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All photos Canon EOS R10 with RF-S 18-150mm lens |
Sometimes camera makers produce a lens the purpose of which seems unclear. Some of these lenses look more like vanity projects than practical tools. One which springs to mind is the Nikon Z 58mm f0.95 noct, a massive, hyper-expensive hunk of glass which offers manual focus only.
At other times they come up with a product which is aimed accurately at a target buyer, which has a clearly defined place in the catalogue and which is eminently practical.
One such is the subject of this review: the Canon RF-S 18-150mm f3.5-6.3 IS STM.
A lens with the same optical formulation first appeared in the now-almost-defunct EF-M mount in 2016. I had, over the years three of these. The first was badly decentered, the second moderately so and the third was well centered on its optical axis. This copy showed that with proper quality control the lens could be a little gem, delivering excellent picture quality.
Now we have the same optical formulation housed in the RF mount and marketed as an RF-S lens to indicate it is for RF mount cameras using an APSC crop sensor. I have used two copies of the new RF-S version of the lens and have found both to be very well constructed having no apparent problem with quality control.
The re-housing process has required a few changes to the external dimensions. The flange-back distance of the EF-M mount is 18mm while that of the RF mount is 20mm. So the optical elements have to be recessed a bit more into the RF mount which has a diameter of 67mm compared to the 61mm of the EF-M mount. The lens barrel has increased from 61 to 62mm in diameter which is still less than the 67mm diameter of the RF mount, giving rise to the characteristic appearance of RF-S lenses. The length in front of the mount has decreased about 2mm and the mass has increased about 10 grams.
Filter size is 55mm.
There is a front control ring on the new RF-S lens as is the case with all RF and RF-S lenses, providing an extra control point for camera settings if desired. The ring can alternatively be used for manual focus if desired.
There is no AF/MF switch on the lens. However there is one on the front of the R7 and R10 but not the R50.
We switch the image stabiliser on and off via the camera Q menu.
The other thing I note is that the maximum magnification has increased from 0.31x to 0.44x at 50mm with AF and a bit more with manual focus. At maximum magnification the lens delivers clear, sharp results making it very suitable for hand held half-macro shooting.
Both lenses have a quite advanced construction with 17 elements in 13 groups with 2 aspherics and a UD element. For a kit lens this thing is rather well endowed.
We might have liked the wide end to extend down to 15mm but this would have made the lens larger, heavier and more expensive. As it stands 18mm on Canon APSC is equivalent to about 29mm on full frame which is wide enough for most use cases. If we have no room to walk back for a wider view there is always the option of using the auto-pano capability of Canon’s crop sensor models.
The 8.3x zoom range is very versatile.
In use the lens functions perfectly on the R7 and R10. I have not tried it yet on the R50 but have no doubt it will work just fine on that body. It is light, compact and quiet. The zoom action is smooth and even. AF is very fast and accurate. In my hands the stabiliser gives about a three EV step advantage which is about average on my tests for RF/RF-S lenses with IS.
Resistance to flare is very good even with the sun shining right into the front of the lens. There is a bit of purple fringing in the corners at the wide end especially with foliage against a hot sky, but this is easily tamed in Photoshop. Distortion is almost fully corrected in JPGs or Raw files converted in Photoshop Camera Raw. Peripheral shading is present at the widest aperture but I rarely bother to correct it.
Image quality is a really strong feature of this lens. I have tested it in many different situations over thousands of frames at all focal lengths and apertures and am very pleased with the results. I can use the lens at any focal length and aperture with confidence I will get very good sharpness, contrast and resolution across the frame all the time. The caveat to this is that resolution of fine details starts to drop off at apertures smaller than about f8 so I do not use a smaller aperture than this in general photography. F11 is best for close-ups however, to achieve a reasonable depth of field.
On the R10 which has a 24Mpx sensor the amount of visual information which can be transferred from subject to output image is quite remarkable. In sunlight or bright overcast the 45Mpx R5 with RF 24-105mm L series zoom is only slightly better and we have to look closely to see it. In low light at higher ISO settings the larger camera/lens combination pulls ahead of course.
Who is it for ? Anybody who has or is planning to buy a Canon EOS R7, R10 or R50. The lens is sold at a discount if purchased with the body as a kit. I recommend the RF-S 18-150mm as first choice lens for any of the Canon RF-S crop sensor bodies.
What is it for ? Anything really. The lens is very versatile. Indoors the f3.5 aperture at the wide end of the zoom admits enough light for hand held work. Outdoors in bright light the lens works well for landscapes city or country, street, documentary, sport and pretty much anything else. The characteristics of both the crop sensor bodies and the relatively narrow aperture of the lens make it less suitable in low light for sport, action and fast moving subjects. Backgrounds cannot be blurred out as much with this lens as they can with wider aperture lenses on full frame bodies.
Comparisons
Compared to the original EF-M version of the lens the RF-S model appears on my limited experience to be built with better quality control. It also focusses closer.
On my tests and published reviews by others, the RF-S 18-150mm delivers slightly better sharpness than the smaller RF-S 18-45mm lens. It is slightly better across the frame at all comparable focal lengths and apertures, offers a wider aperture at each focal length and 3.3x the zoom range. If you don’t mind the extra length and price of the 18-150mm it is clearly a better lens than the 18-45mm. I am not suggesting the 18-45mm is a bad lens by any means. I have used the 18-45mm quite a lot and on its own merits it does a very nice job.
Summary
The RF-S 18-150mm is highly recommended. It is my top recommendation as first lens for anyone getting a Canon RF-S crop sensor camera.
