Canon EF 40mm f/2.8 STM Lens

• Ultra-slim and lightweight design
• Aspherical lens element delivers high image quality from the center to the periphery
• Advanced optical design enables a bright f/2.8, compact optical system at 40mm
• Optimized lens coatings ensure exceptional color balance while minimizing ghosting and flare
• Built-in stepping motor provides smooth and quiet autofocus when shooting video with Canon EOS Rebel T4i DSLR

"Pancake" lenses have always had an appeal to SLR shooters. Their dimunitive size and weight, as well as overall simplicity, make them ideal as walkaround lenses, and many find the focal length of 40mm (give or take a few mm) much to their liking for general photography. Contax, Pentax, Nikon and other manufacturers have produced their offerings throughout the modern photographic era. Panasonic and Olympus have pancake lenses for their micro 4/3 lenses. For some mysterious reason, Canon has remained silent on the issue since 1965, when it produced the FLP 38/2.8 for a limited time. Until now. Let the celebration begin.

I had the pleasure of owning the Pentax and Contax Zeiss lenses in the days of film. I loved them both, and they were never far from reach. When I bought Canon dSLRs, due to lack of any Canon pancake lens being available, I adapted both the Contax Zeiss and the Pentax pancakes to work on my 5D, 5D2 and 40D. Of course, this arrangement has serious limitations, as both the autofocus and the aperture have to be set manually, making for a slow, awkward shooting experience. At very long last, Canon has brought its own pancake lens to market, in the form of the EF 40/2.8 STM.

It is strikingly small and light, and if you've never seen or experienced a pancake lens before, you're likely to wonder how a lens can be so small and even work on full framed dSLRs. Despite its size, there is pleasing build quality to be found. Built nothing like the EF 50/1.8 II, there is a metal lens mount and a solid lens barrel, short as it is. Canon was barely able to fit the AF/MF switch on the barrel, the barrel is so short. I would compare build quality to the EF 50/1.4. Aesthetically, the 40 has a sex appeal all of its own. There's always been something about those pancakes and they way they look and feel. Canon certainly does not disappoint here.

Optically, I have found the 40/2.8 to perform in excellent fashion. CA is well-controlled, I have not experienced problems with flare, and I do not have a hood attached. Center sharpness at f/2.8 is excellent, and I have uploaded a photo here to help demonstrate. Corners look very good as well. Color rendition is excellent, and bokeh is much to my liking.

Mechanically, the AF is fast, quiet and accurate, and the new STM focus stepping motor technology is employed here. I don't shoot video, so I couldn't care less about the lens being quiet for filming of video, but that may we a huge deal for those of you that do use the video features of your dSLR.

While Canon points out that this lens makes it possible to shoot more discretely, I suppose that's true to a point. But it's rather difficult to achieve shooting discretion when the lens is mounted to the larger non-Rebel Canon bodies, being the big black blobs that they are. However, the pancake design does make your shooting experience very pleasant in that there is not a long lens sticking outing of it. Combined with the weight reduction, the shooting experience with this lens mounted to your camera is bliss. I will be using it a lot as a walkaround, and for vacations.

A possible issue with this lens concerns its use with a cropped sensor camera body. The crop on the 1.6x bodies results in a 64mm effective focal length. I'm not sure how useful a 64/2.8 lens would be for most shooters. For me, that's not very useful. You may disagree. I'll vouch for the usefulness of this lens on a full frame body.

I highly recommend this lens, and at this price point, it's a no-brainer to click the Buy button.

Happy snaps!

Buy Canon EF 40mm f/2.8 STM Lens Now

Before going into the details of my review, I'd like to start off by saying...if you have the money on hand, you should immediately buy this lens. I am extremely pleased so far this is a lightweight, yet solidly built, and extremely affordable performer. While two hundred bucks doesn't seem "affordable" at first, it delivers very solid results that you could expect from lenses that cost several times as much.

To give some background: I do shoot professionally, but got this lens mostly for personal use I simply prefer the versatility of a zoom lens for professional work, although seeing the impressive results I might incorporate it for future assignments. I currently own two bodies, a 5D Mark II and a 7D. While my main lenses are high-end (the 24-105L, 70-200L 2.8 IS II, and 100mm Macro), since I started off with a Rebel series body I also am familiar with a lot of the cheaper lenses Canon sells, including the 50mm f/1.8. I really liked the 50 f/1.8 because of its convenient size but by comparison to this lens, it now seems big!

I love this 40mm f/2.8 lens on both of my bodies, but find its focal range to be much more useful on a full-frame than crop-sensor body. Keep in mind that if you have a crop body, the effective focal length of this lens comes out to 64mm! Even at that length, you can still get impressive shots with beautiful bokeh, but in my experience 64mm was more inconvenient to work with than 40mm. I'd still recommend it for APS-C bodies though, because the image quality thus far has been very impressive.

PROS

* Very small lens, which allows for much more inconspicuous shooting if you want to blend into the background. This lens is tiny! Yes, mounted on a battery-gripped SLR you still stand out a bit, but not nearly as much as you do with most other lenses

* Very light this is much more portable than any other lens I own. You could even carry it in a pocket.

* Great image quality. I really am impressed at the results based on the low price point

* Impressive build quality. This lens might be inexpensive, but it doesn't feel cheap.

CONS

* Hard to manually adjust focus. This is my only major gripe with this lens. It is doable, but it definitely takes getting used to. This is especially pronounced if you have big hands. That being said, I think the convenience of the small lens size makes up for this minor inconvenience.

* Yes, as some other reviewers have already mentioned, there is some vignetting wide open. This doesn't bother me too much as I find the vignetting to be acceptable, but some others might not like it even if it can be corrected in post-processing it depends on personal preference

CONCLUSIONS

I will try to upload photos demonstrating this lens' ability in the next few weeks; in the meantime, some people have already added to the gallery here, and undoubtedly many pictures will start appearing on Flickr.

Some people will inevitably find the need to ask why I gave the lens 5 stars if there are some cons. For the price I paid for this lens, I am very happy with my results, and think the cons are outweighed by the pros. The size and weight of this lens are remarkable, and its optical performance is great for the price. Sure, you could compare this lens to much more expensive ones and find more shortcomings, but I think for most people's use, this lens is a terrific buy. The other reviewers thus far also seem to be happy with their purchase, which I think is a testament to the performance of this lens. I highly recommend you go for it!

Read Best Reviews of Canon EF 40mm f/2.8 STM Lens Here

Please don't take the Amazon star rating too serious every lens has its pros and cons that I wouldn't want to squeeze into a single one-dimensional figure...

A quick note about me: I have been into SLR cameras and lenses for more than 20 years as a hobby in the beginning and professionally later. Maybe because of my technical background I started testing my own lenses quite a while ago. I have a (no longer so) little test lab of my own where I do 6 different image quality tests (after taking a lens out for a while).

Canon's first-ever "pancake" EF lens is a real treat. It's so small that it looks like a 20 mm extension ring rather than a lens and yet it feels solid as a rock and delivers very respectable image quality. It comes with Canon's stepping motor technology (STM) that allows continuous AF during video recording or live-view mode (when used with a hybrid CMOS AF system) and that gives the lens a fast, silent and accurate autofocus performance. The EF 40mm f/2.8 STM is best used for street and travel photography but can also make great portraits or other things. Its maximum aperture of f/2.8 is great but not good enough for available light photography (which requires even lower f-stops i.e. wider apertures) and I would have loved to have an image stabilizer but of course that would have been very difficult to build into a 2.7" x 0.9" (68 mm x 23 mm) lens.

In regard to image quality the EF 40mm f/2.8 STM is really a high-end lens. The difference is most apparent if you compare it to a zoom lens but also amongst prime lenses of similar focal length the EF 40mm f/2.8 STM is a high performer. The resolution is great straight from f/2.8 both in the image center and corners. If you use a fullframe camera the EF 50mm f/1.4 USM is a little sharper and the EF 50mm f/1.8 II is about as sharp as the EF 40mm f/2.8 STM (compared at the same aperture). But if you shoot with an APS-C camera the EF 40mm f/2.8 STM easily outperforms both of those lenses (apparently it can cope better with the usually higher pixel density of APS-C cameras). It is roughly as sharp as the APS-C-only EF-S 60mm f/2.8 Macro USM (which is more than 3 times its size).

While the EF 40mm f/2.8 STM shows only very little distortion it does express some serious curvature of the focal plane ("field curvature") on a fullframe camera (none on an APS-C cam) but whether that's really visible in an actual image depends a lot on the subject you are shooting and the aperture you are using. Color fringes ("chromatic aberrations") in focused parts of the image ("transverse CA") are noticeable and so are the ones that occur in out-of-focus parts of the image ("axial CA"). On the good side, the nicely shaped aperture creates evenly smooth background blur but if you are bothered by corner shadows ("vignetting") be aware that the EF 40mm f/2.8 STM shows quite intense shadows up to about f/5.6 (with fullframe cameras).

Overall the image quality is quite astonishing for a lens that's as small as the EF 40mm f/2.8 STM and that comes at such a low price tag. This also means that from now on you can always have a decent f/2.8 prime lens with you that virtually needs no space in your camera bag!

Canon set out to create their first pancake lens and they did it the right way combining great features with an incredibly small size at an acceptable price. I am sure many people will love the lens just for its size and the way it feels but even beyond that the EF 40mm f/2.8 STM has a lot to offer.

A much more detailed review of this lens together with all test shots, sample images and technical data is available on my website LensTests_com.

Want Canon EF 40mm f/2.8 STM Lens Discount?

I will openly admit, I am a fan of a true 50mm lens, and when I saw this (especially at the price) I was highly skeptical. However, having shot with both Canon and Leica camera's, I knew of Canon's general quality, and from Leica the general flexibility of a pancake lens.

I will keep this review short and sweet; I love the lens. It hasn't left my camera for 2 weeks now. I work as a professional photographer / graphic designer, and understand the tools of my trade. The images are tack sharp, the bokeh is superlative, and the speed is excellent. And with the price being so low it is hard to not justify this lens.

To quickly touch on the setup I am shooting with a Canon EOS 60D (same sensor as 7D), and use the B+W multi coat filter, as well as the ES-52 lens hood. The images are excellent.

Few months ago, I purchased the 40mm pancake after reading all of its good reviews. My experience with this lens is that it did produce sharp and good color indoor pictures as many reviewers have pointed out. The rate of focusing was also pretty good in my opinion consider its relatively cheap price. So I was very happy and excited about this lens. However, my initial excitement turned into disappointment when I took the lens outdoor to begin taking pictures with it. Almost all of the outdoor pictures are soft. When I reviewed these pictures with DPP, the focus points of all the pictures are correct. They are where I wanted them to be. The problem is that the focused areas are soft, but the areas that are outside the focused points are sharp. This seems to me that this lens is either having a back or front focus problem. I don't know if this focus problem is the same that Canon mentioned in their website in which it is mentioned that the lens will fail to focus when it is moderately touched. I understand there is a firmware update that can fix the problem, but the problem with the firmware fix is that it will only work on newer camera models such as 5D MK III. For other older models, the lens needs to be sent back to Canon for fixing. Why would someone want to buy a new lens knowing that it potentially has to be sent back to the factory for repair?

Another aspect of this lens that causes concern to me is the mount. Yes, the mount is metal, which is very good. However, when I tried to mount it to my 7D, I needed to apply some force in order to make it turn and lock in place. I don't have this problem with the 28-135 kit lens that I have. The 28-135 turns smoothly and locked in place easily. Now think about this: with this tight fitting, will it cause unnecessary wear to the mounts of both the lens and camera? I don't care much about the lens' mount. After all, it is only a $200 investment, but I can't say the same for the camera. If the camera needs replacement, I can't imagine how much it will cost.

Considering these two factors, I returned the lens to avoid getting stuck with it.

I would also like to point out that I will not call this a review, but rather an account of my personal experience with it. I hope this will help you to make your purchase decision.

[UPDATE: Nov 10, 2012]

Because of the $50 price drop, I decided to give pancake a second try.

This second sample doesn't have the updated firmware (which I hoped for, but didn't came true) as the serial number indicates. Regardless of the absent of the updated firmware, this second sample seems to be better than the first one that I had. The mount is not as stiff, but still needs a little strong twist than normal in order to lock it. The sharpness is also better, but this improvement came with a caveat. I get very tart sharp picture only when I use the single center focus point. When I use any other focus modes or points other than center one, the sharpness is just OK, and sometime it is just plain soft. I know this softness problem is not with the camera because it doesn't happen when I use the 28-135.

I want to change the rating to 3.5, but this rating isn't any available. And for these two samples that I got, I don't think this lens fix the 4 star rating. Sorry, pancake...

I am now pondering whether I should return this and try a next copy again. If I do, I will update the review with the experience that I will have with it. Thank you for reading.