First Impressions: Canon EF 40mm f/2.8 STM

Pancakes! Everybody loves them, right? Well someone at Canon sure does because they have finally given us a pancake lens for the EOS system. The EF 40mm f/2.8 STM is a full-frame lens (it of course works on APS-C bodies as well). So is this tiny lens a worthwhile addition to your lineup? Read on for my first impressions.



(Taken from B&H’s site)

Focal Length 40 mm
Comparable APS-C Focal Length: 64 mm
Aperture Maximum: f/2.8
Camera Mount Type Canon EF
Format Compatibility 35mm Film / Full-Frame Digital Sensor
Canon (APS-C)
Angle of View 57.3°
Minimum Focus Distance 11.81″ (30.00 cm)
Groups/Elements 4/6
Diaphragm Blades 7
Image Stabilization No
Autofocus Yes
Tripod Collar No
Filter Thread Front: 52 mm
Dimensions (DxL) Approx. 2.7 x 0.9″ (6.86 x 2.29 cm)
Weight 4.6 oz (130 g)


The EF 40mm f/2.8 is the smallest lens currently produced by Canon for the EOS system. It has a new type of AF system (for Canon) called a stepping motor (STM for short). This AF motor is designed to work with the Live-View AF system of the new T4i (and presumably future DSLR body releases from Canon). The idea behind the stepping motor is that it’s supposed to allow continuous AF during live-view and video recording with the Contrast-Detect AF (CDAF) system of the new T4i. Given that I don’t presently have a T4i, I can neither confirm nor deny this improvement in AF speed during live view.

Despite this, I did note that the lack of a USM motor meant that the speed of autofocusing was not QUITE as fast as my other Canon lenses. However, it is certainly quick enough for most uses, and I also found it to be just as accurate as my USM based lenses. Obviously the big selling point behind a lens such as this is its extremely compact dimensions and light weight. You could literally fit this lens in almost any pocket (with the exception of extremely skinny jeans) and it wouldn’t even weigh you down any more than your cellphone.

First Impression

The compact size of this lens was the main reason for my purchasing this lens. Moreso than focal length or lens speed, I was dying to have a compact lens that would allow me to take my 5DmkII with me daily and not have to carry a bulky setup. This is because I no longer have a compact camera system and my 5D remains as my main digital camera. Right out of the box I was really impressed with the level of build quality for a lens of this size and price. By comparison, the EF 50mm f/1.8II is pretty much entirely plastic, right down to the lens mount. Does this make it a bad lens? No, certainly not, I just tend to prefer things with a more solid construction. Because, even though I am careful with my equipment, it does get used hard and I expect it to hold up for more than a year.

In my firsts tests of the lens I was quite surprised how crisp the center image is at f/2.8, the corners of the frame are pretty good, but by f/4-5.6 they are excellent. I need to do more testing at other apertures, but I will likely be using the lens between f/2.8-4 quite often. Another great feature of this lens is its minimum focus distance of .3 meters (less than 1 foot), this allows you to focus quite close to your subject. This is awesome for close up portraits or even small products.

Taken @ f/5.6 at minimum focusing distance

I will continue to test out this lens in the coming weeks and further inspect its capabilities, but so far, for under $200, I think this is one heck of a good deal. If you’re interested in purchasing one already, then you can do so right here. I will leave you with a few more image samples.

Taken at ISO 3200 hand held

Please Support The Phoblographer

We love to bring you guys the latest and greatest news and gear related stuff. However, we can’t keep doing that unless we have your continued support. If you would like to purchase any of the items mentioned, please do so by clicking our links first and then purchasing the items as we then get a small portion of the sale to help run the website.

Also, please follow us on FacebookFlickr and Twitter.