I won't make this review lengthy, because it's all been said before, but I will qualify myself by saying that I depend on photography for approximately half of my income, and I recently purchased this lens after many hours of online research. I own a Canon 7D, and I was looking for a lens that would fall into the wide/portrait range with the 7D's 1.6x crop factor. This lens was bought as a replacement for my old Tamron 28-75, which was a respectable lens. The Canon 17-40 has thus far been a very solidly built, light, fast-functioning lens. It autofocuses VERY quietly with its ultrasonic motor, and the autofocus is very accurate. On the 7D, I have found it to be a capable portrait lens at 40mm, as well as a great lens for interiors. I bought it as a complement to the Canon 70-200L, for a lightweight kit, and while I am missing the 41-69 focal range, I haven't really needed it. The lens produces VERY SHARP photos, and is much more reliable in quality than the Tamron. I would definitely recommend it to 7D users wanting a versatile walkaround lens, or to full frame users looking for an ultrawide with great sharpness.

I read this comprehensive review before purchase and you should too:http://www.imaging-resource.com/PRODS/canon-eos-m/canon-eos-mA.HTMI'm an amatuer photog for more than 40 years. Until recently, my only concession to digital photography was the purchase of inexpensive Canon point-n-shoots. As film photography has become a greater burden and digital has caught up in terms of quality while surpassing in convenience and affordability, my discovery of this little gem at a bargain price was perfect timing. Adding a $15 adapter, I can use may ancient but excellent FD mount Canon lenses - think F1 and AE-1 cameras. Auto-focus speed doesn't matter to me because I still prefer to manually set almost everything. That said, the AF performance of the EOS M seems equivalent to that of my son's Nikon 1.My purchases for my entry into serious digital photography to date include: the EOS M with Speedlite 90EX and EOS M 18-55mm IS lense: an SD card (PNY 64 GB High Speed SDXC Class 10): a spare battery (Opteka LP-E12 LPE12 2000mAh Battery Pack): a lense adapter (Fotasy Canon FD Lens to EOS M Lens); and a neck strap (OP/TECH USA System Connector Super Pro A).

I use this lens primarily for video on a Canon 7d Mark II. This lens provides silent, fast and accurate autofocus for video.

If you want to use your old FD lenses, this is one of the best choices. All you need is an adapter ring "Fotasy Canon FD FL Lens to Canon EOS M". The pictures turn out great, you just have to get used to the manual adjustment but there is an automatic ISO adjustment to help, if you want.

Extremely pleased with this lens for video and photos. I am using a Canon RP so I have to use an adapter but I am having no issues at all.

I am using this lens for Canon M50 Camera. You will need EOS adapter. I have attached 3 photos taken with this lens.

I love the lens and sharpness of pictures produced by it. I use it with a Canon 7D and the results are just amazing. I am not a professional photographer, i Just do it for fun and like the pictures that I take from this lens. This is my go to lens now!

I purchased a Canon FD to Leica M adapter in order to get some more use out of my 17mm Canon lens. I’m pretty impressed with it so far. It seems considerably better quality than the cheap imported adapters, and not as expensive as a Novoflex. The lens hooks up solid and it feels solid on the camera body. I will most likely try some of their other adapters as necessary.