Bought this impressive little lens with a Canon SL1. Makes my camera feel even smaller. Pictures are amazing and portability is great. Good at night shots and even better for portraits. Focus is not as fast and quiet as the new18-55mm STM that comes with the SL1, but its still a great lens.

I am using this lens with an SL1. This is a great camera and lens combination. I have the 18-55 STM which is also very good, but the size, image quality and small aperture of the 40mm makes it an excellent all around carry lens.

Image quality; size; aperture; build quality

None

I bought this lens to go with the RP body (with adapter). Lens and adapter is shorter/smaller than the smallest RF mount lens offered presently. RP hasnt arrived yet, but on my 5DmkIII Im getting results far beyond the price of the lens. Almost perfectly sharp, corner to corner, wide open.

This lens just arrived yesterday and I think it will be just perfect for my purposes. I wanted a small lens to put on my 60D that had a large aperture ,a close focusing distance and did a decent job of rendering backgrounds out of focus.

Easily Interchangeable; Fast / accurate auto-focus; Lightweight; Nice Bokeh

Not Easy To Manual Focus

Great lens for the money.

It is sharp, F4+ is really the sweet spot here. Wide open the photos are usable but some distortion occurs in lower light settings. I used this lens at the aquarium and got some very good and usable shots from 2.8-5.6.

Decent Focus; Low light; Portable; Sharp

Build Quality; Some Noise Wide Open

This is a brilliant lens that is wonderful to use out on the street due to its very low profile. When I take the battery pack off my 5D Mark III and replace my Canon "cannons" with this lens, I feel like I'm carrying a point and shoot!

Bright Image; Easy To Use; Quality Construction

None Discovered So Far

For the money, this lens is great. I use it on a 5D Mk 2 and it works really well for product photography.

Small and lightweight Sharp

None that I can think of at this price

I have heard this lens described as cute, tiny and a toy. I suppose it is cute and it is very small but it is not a toy. The build quality is very good. It will add only 130g to the weight of your camera.

Wait!!!! It's Sharp!!! Well, the review is for all those who are in dilemma between 50mm f1.8 and 40mm f2.8. On the spec sheet one would think that 50mm beat the hell out of 40mm, with it's larger aperture and better focal length for portraits.

The lens provides excellent auto focus for both video and still. I am using the lens in EOS-650D which gives an excellent clarity for portraits and closeups.

Fast / accurate auto-focus; Nice Bokeh

Lens Creep