DxOMark analyzed the EF 40mm f/2.8 STM (price & specs) using a EOS 5D Mark II (price & specs), and the nifty pancake got figures:

Considering its relatively low price, the EF 40mm f/2.8 STM was a solid performer on our DxOMark Camera Lens Ratings. […] it rates among the top seven standard prime lenses (with a focal range between 35mm and 85mm) achieving an overall DxOMark Score of 26.

Strengths of the Canon EF 40mm f/2.8 STM include resolution […] Additionally, our sharpness measurements and field maps […] indicated that the lens delivered relatively consistent edge-to-edge sharpness from f/2.8 to f/11.

Other strengths include its low geometric distortion and well-controlled chromatic aberration as indicated by its low Chromatic Aberration score of 10µm.

The one weakness of the Canon EF 40mm f/2.8 STM was the strong vignetting evident at the widest apertures. You can see from the vignetting field maps below that at f/2.8, there is heavy shading across 2/3 of the field.

The Canon EF 40mm f/2.8 STM actually has price tag of $149. A bargain for a lens that has such a good perfomance (click on shop name): B&H Photo, Adorama, Amazon USA, Amazon Canada, Canon Canada, Canon USA.

The 40mm pancake performs slightly better than the much pricier Canon EF 50mm f/1.4 USM(price & specs), and the cheaper EF 50mm f/1.8. As you can see, all three lenses have very good sharpness figures.

[via DxOMark]

The Phoblographer posted their Canon EF 40mm f/2.8 STM review. Another very positive review of Canon’s cheap and sharp pancake lens. The reviewer was

[…] was extremely surprised with the Canon EF 40mm f/2.8 STM lens, the image quality delivered was beyond what I expected from a lens at this price point. I do wish the manual focus feel was a bit more responsive, and the AF speed just a touch faster, but I can certainly live with it as-is and have no issues. For $150 (as of Nov’ 2012) I feel like this should be a no-brainer purchase if you want the smallest lens that Canon currently produces.

Pros and cons:

• Tiny physical size
• Accurate AF
• MFD under 12″
• Very, very good image quality
• Better AF during live-view (on STM friendly cameras like the T4i)
• Highly Flare Resistant
• Inexpensive!

Minuses:

Update: Adorama also has the EF 40mm f/2.8 STM for $149 (click here)

A Canon EF 40mm f/2.8 STM reviews roundup. The small and super sharp Canon EF 40mm f/2.8 STM ($149 on Amazon) pancake gets absolutely positive reviews. Keep in mind that this is a sub $199 lens! I really would like Canon was giving us more high quality gear at an affordable price.

Let’s start with The Digital Picture’s comprehensive review. Some excerpts from their review:

• Small size and small price are great, but … image quality is a sacrifice one would expect to make to gain these attributes. Amazingly, the Canon EF 40mm f/2.8 STM Pancake Lens delivers impressively in this regard.
• The Canon EF 40mm f/2.8 STM Pancake Lens is very usably sharp at f/2.8 with a modest increase in softness as the outer portion of the image circle is reached. Stopping down to f/4 results in a sharp image across the frame save the extreme full frame corners. At f/5.6, even the extreme full frame corners are very sharp – allowing this lens to compete with lenses at far higher prices.
• CA (Chromatic Aberration) is very well controlled – nearly absent. Same with flare. Even with the sun in the full frame corner, flare is hard to notice. Flare performance is certainly advantaged by the use of only 6 lenses in 4 groups.

Next, The Phoblographer:

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.

Scott Bourne at Photofocus:

It’s fast – f/2.8. It’s light and small, less than one inch long – it uses a high-quality aspherical element and is coated to reduce flare. The detail this lens produces is nothing short of a miracle given its price point.

One of my favorite features about this lens is it’s close focusing distance of just under one foot. This means that those of you who want to use this for street photography and who understand how to use hyper-focal distance will never have to worry about focus – AF or not. You’ll be able to shoot thing anywhere from one foot to about forever.

Finally, EOSHD thoughts about Canon’s pancake

Canon have produced a decent lens here for the price. It does make your Canon DSLR more stealthy like a mirrorless camera. Well – 50% of the way there. It has advantages with an anamorphic as outlined above although that is a very niche use for it, it is the main reason I bought one. AF on the lens although not silent is fast, and the aperture seems to have the ability to be continuously variable rather than stepped in movie and live view mode on cameras that support it.

Close focus is excellent, right down to 0.3m or just less than 1ft. By comparison the already quite nifty Olympus 45mm F1.8 gets to around 0.5m and the Lumix 20mm to 0.2mm although that has a considerably shorter focal length. Vignetting is fair on full frame, no disaster and certainly not an issue on a crop sensor. Corner sharpness wide open isn’t great on full frame but again this is fine on a crop sensor. Centre sharpness wide open is pretty good, I’d say above average here as is suppression of lens flair although there’s some purple fringing when not removed in-camera or in post. Distortion I’d say it was average. Nothing to get too excited about here. Build quality though is definitely above average for the price range.

I want one! :-)

Canon EF 40mm f/2.8 STM price check: B&H Photo, Adorama, Amazon USA, Amazon Canada, Canon Canada, Canon USA

 

 

 

Intersting article by professional photographer Andrew Gibson at picturecorrect about advantages of pancake lenses in general, and of Canon's supersharp EF 40mm f/2.8 STM in particular. The pancake is tested for various photograhic settings, i.e. landscape, portrait and so on. Close up/macro photography is also contemplated. Moreover, EF 40mm f/2.8 is lightweighted, not too espensive ($199), and has excellent optical properties. From the conclusion:

Landscape photography aside, the Canon 40mm pancake lens hasn’t disappointed. It’s light, well-built, the autofocus works well and it has excellent image quality. Furthermore it’s one of Canon’s cheapest lenses and probably the best value for money out of the entire Canon range.

Technical specifications of the Canon 40mm f/2.8 STM:

• Continuous Autofocus for Video With Rebel T4i/EOS M
• Bright f/2.8 Aperture
• Lightweight 4.6 oz Lens
• Unobtrusive–Less Than 1″ Long
• Aspherical Element–High Image Quality
• Optimized Coatings Reduce Ghost & Flare
• Exceptional Color Balance
• 7-Blade Diaphragm for Beautiful Bokeh
• Close Focusing to 11.81″
• 64mm Equivalent If Used on APS-C Camera

Canon EF 40mm f/2.8 STM price check: B&H Photo, Adorama, Amazon USA, Amazon Canada, Canon Canada, Canon USA