Canon EF-S 10-18mm IS STM

As I started out with just the Sony FE 28-70 kit lens for my Sony A7, I started exploring ways for me to expand my lens collection. I found that 28mm, the widest I could go in my setup, was not enough for me. Selfies would be a bit too tight, and I couldn’t capture everything that I would like when I found myself in a tight spot. So I started to look for lenses that would satisfy my needs!

I started out by looking at Sony UWA zooms. There’s the FE 16-35 F4, the GM 16-35 F2.8, the 12-24 F4, and the APS-C Sony 10-18 F4. Out of all of these, only the 10-18 APS-C could be considered cheap, although if you look at what Canon offers at the same price point, there’s a lot more choice in lenses! Furthermore, the second-hand market for Canon lenses is a lot better!

So next, I started to look at Canon lenses, which I could use with my Viltrox EF-NEX IV mount adapter (see review). I had previously tried an old Canon 17-35 F2.8 L, which seemed to work nicely. However, even second-hand, these can be quite pricey, so I started to look at the Canon 17-40 F4. Regrettably, the AF motor on this way too noisy to use for AF-C video, even though it sported Canons Ultrasonic USM focussing mechanism. It was at that point that I realized I needed to find a lens that has a quiet focussing motor, such as the STM lineup of Canon lenses. Luckily Canon offers an UWA in that range, and that’s how I decided to purchase the Canon EF-S 10-18 IS STM.


For the price, you really cannot expect much from this lens. However, it sports Canons super silent STM focussing mechanism, and even includes image stabilization! Regrettably however, the aperture ranges from 4.5 to 5.6, so there’s not a lot of light coming into this lens. I figured, with the low-light capability of the Sony A7 III, that shouldn’t be a problem.

The uncommon harmony between Sony and Canon

The focal range is great! In FF FOV terms, this would give me a range of 15-27mm, so it aligns perfectly with the range of my FE 28-70 lens. Being a APS-C lens though, this sets the A7 to crop-mode. I’m not sure why, but the combination of this limited-aperture lens and the cropped sensor, the picture I take always look a lot more grainy than I’m used to with my other lenses. For one, this lens seems to underexpose by at least 1/2 a stop, so that’s something I always have to keep in mind. The photo below was exposed with the exposure compensation dial at +1,0. Apart from a WB adjustment, this image came straight out of the camera.

To overcome this, there is a trick you can use. If you set the A7 to full-frame mode, by setting APS-C mode to ‘off’ instead of ‘auto’, and you set the lens to 14mm, you can shoot at 14mm full-frame without being blocked by the inside of the lens At 14mm, this lens just about covers the whole sensor of the A7. This is a trick I learned from someone who performed this trick on the native Sony APS-C 10-18mm lens. While the Canon 10-18 will still show a heavy vignette, more than the Sony 10-18 does in the YouTube video, this is certainly something you can easily crop away. This allows for using more of the full-frame sensor of the A7, thus resulting in decreased noise, a wider FOV and more light hitting the sensor.

Vignetting present at 14mm in full-frame mode on the A7

The STM works silently in AF-C video mode. I’ve never heard the focussing motor make noise on the recordings, just as with native Sony E lenses. I’m not sure if IS works, as I cannot set the IBIS manually. Does this mean IS is functioning and working together with IBIS? I’m not sure… The image is stable enough though, and in the end, that’s all that matters.

The AF performance, when combined with the Viltrox EF-NEX mount adapter, is okay-ish. In dark environments, AF can hunt a lot, but in normal circumstances, AF performance is adequate.

Unfortunately, Canon does not ship the hood for this lens. Luckily, a cheap one can be easily found (link). Note however that mounting the hood results in it being visible if you perform the full-frame trick I mentioned previously.

UWA for full-frame Sony on the cheap



  • Cheap
  • Lightweight and (relatively) small
  • Quiet AF due to Canon STM focussing motor
  • 14mm on full-frame mode possible
  • Image stabilization


  • Tendency to underexpose
  • Very slow lens, small maximum aperture (4.5-5.6)
  • APS-C

Overall, I’m quite happy with this lens, as it was quite cheap, and it gives me the creative freedom to explore UWA. Considering the lackluster performance of the A7 III in APS-C mode, I think I will consider the FE 16-35 F4 to upgrade from this lens. However, for the time being, this lens will suit me just fine!


One thought on “Canon EF-S 10-18mm IS STM

  1. Hello, hows your testing going? I have a sony 7riii that I’m really planning to use with this lens ( I own the lens and a metabones V). I checked the autofocus and works well, really low light at f5.6, but Im going to mount it on my moza air 1 and need to shoot at about 35mm (please ask me to shoot the same FOV as a cellphone) and my only other lens at 35mm is a 24-70mm that is massive and makes it too front heavy for the gimbal. I’ll keep playing with it.


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