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Reviewed in the United States on December 22, 2024
Verified Purchase
This review is my first impressions of the lens. I haven't spent a lot of time with it yet, so if my opinion changes, I will come back and update this review.
To begin with, I was really happy to find this lens. I got a Canon R7 a few months ago along with the RF 100-400mm lens as I do a lot of birding and wanted a lighter-weight rig for the field than my 6D with EF 100-400mm lens. However, I also like to do landscape and travel photography when on vacation and the occasional milky way or aurora astrophotography shot. The 1.6x crop factor of the R7 makes it really hard to get wide landscape shots. Through an adapter, I tried my 17-40 lens on it that is my go-to for landscapes on the 6D and it was nowhere near wide enough. I needed to be much wider than 16mm on the R7 to get the shots I wanted. I thought the Canon RF-S 10-18mm f4.5-6.3 was my only option and was ready to buy it when I saw the announcement that Sigma was coming out with an f2.8 version. Fantastic! That f2.8 will make a huge difference for astrophotography.
I watched it for a while and pulled the trigger on a used one on 鶹 from Gabrians (Note the price was good at $549 but the shipping was ridiculously slow- ordered Nov. 29th, arrived Dec. 13th. It was also sent signature required but didn't indicate this anywhere, so I had to arrange a trip to the post office to pick it up the next day as I was not around to sign for it). The lens itself is a nice size and weight. It comes with a small lens hood. I screwed on a UV filter / lens protector immediately and took some test shots. There didn't seem to be significant vignetting with the filter on, which was a pleasant surprise. I was expecting a lot of drop-off at the corners based on other wide angle lenses I have used, but it wasn't noticeable. Even if it was, RAW converters are excellent at fixing that automatically anyway.
Focusing is very fast and quiet. So quiet, in fact, that I can't even hear it. I don't particularly like the zoom ring however. Everything about it is backwards from every other lens I have used. It is the further ring from the body, not the closer one, unlike just about every other lens I have. Second, the rotation is the opposite direction of every other lens I have. You rotate it counter-clockwise to zoom in and clockwise to zoom out. That's really the only complaint I have about this lens.
The manual focus / multi-function ring works as expected and manual focus override works well with the R7. The lack of image stabilization in the lens isn't a problem since the R7 has in-body stabilization. In my limited testing, the photos came out sharp and I didn't notice any chromatic aberration problems. Close focus is very close. At 10mm it can focus on something pressed right up to the edge of the lens hood.
Overall, I give this lens 5 stars for now as it seems like a good lens and fills an immediate need for a fast, ultra-wide angle for crop sensor RF cameras. About the only thing missing from it that I would like is weather sealing for peace of mind.
5.0 out of 5 starsIf you have a Canon R7, this is a fantastic lens
Reviewed in the United States on June 27, 2025
Verified Purchase
Initial thoughts...Very sharp, compact, and lightweight. Utilizes the 32.5MP sensor of the Canon R7 very effectively. The extreme corners are slightly soft, but unless you look very close, you wouldn't notice. I am so impressed with this lens that I will be leaving my Canon RF 15-35 mm f/2.8 lens at home on my trip to Alaska and taking this lens instead to save some weight. On a non-cropped camera, the resolution drops to approximately 9.3 MP at a 1.6 percent crop. The crop is selected automatically and cannot be changed. If you have a Canon R7, this is a fantastic lens. I don't normally buy third-party lenses, but this lens is faster than the Canon Crop body equivalent lens, albeit twice the price.