Flat As A Pancake – The New Canon 40mm f2.8 STM Lens


I had never in my life heard of a pancake lens until one of the photography sites that I frequent trumpeted the announcement of the Canon 40mm STM f2.8 pancake lens. I then discovered other pancake lenses: Samsung puts out three of them: the 20mm, the 30mm and the 16mm, and Voigtlander also sells three of them: the Ultron 40mm,  the Color Skopar 25mm, and the Color Skopar 21mm.

A pancake lens is a reallyflat lens – in the case of the Canon model, the lens is about one (1)  inch tall. Really!  A 1-inch tall lens on a DSLR.



It looks like this on my camera:


When Canon announced this lens, with a price of $199, I said to myself: “Self, you should get this lens. It’s not that expensive, it sounds fun, it’s certainly smaller and lighter than your 50mm f1.2 lens.  Plus, it’s got a slightly wider view for those group shots. Granted, it’s not an L-lens, with that supreme L-lens quality, but nonetheless…..”

So, I placed a “pre-order” for this lens, since it was not yet in stock. A pre-order means the camera company has your order on record (i.e. in the queue with all of the other pre-orders for an item not yet in stock), but until said item arrives, they won’t charge your credit card or Paypal account.

Two full weeks later, still no lens. I lost my patience, rationalized to myself as to why I really didn’t need the 40mm pancake lens, cancelled the “pending” order and instead opted for the Canon 2x teleconverter. We all know how that worked out.

So, I re-ordered the now in-stock lens.

The 40mm pancake vs. the 50mm L lens on a camera:



First impressions right out of the box: It’s so cute! ;D

Ok, now for a little more helpful set of first impressions:

  • The pancake lens is so very light.  And, as you can see, the glass itself is pretty small, compared to the glass of the 50mm lens.  This gives me an indication that the L-lens  probably allows in more light than the pancake lens will.
  • The pancake lens feels relatively sturdy.  I’m comparing this to what I remember of the 50mm f1.8 lens I used to own, which both looked and felt a little on the flimsy side (my apologies to those of you out there who own and love this lens – remember, this is just my opinion).
  • The pancake lens was easy to attach to the camera.  I’ve read reviews where it’s a little difficult (especially for larger hands) to work with the manual focus.  I haven’t tried to use the manual focus because I generally don’t use manual focus on any of my lenses; my eyesight is not what it used to be at 51 years of age, so I generally rely on the AF.
  • Speaking of  AF, you probably want to know about this fancy STM focusing.  In a nutshell, that means the lens is supposed to ensure smooth and silent continuous focusing – especially important to those using the video mode on their cameras.  I personally found the focus motor noise to be practically non-existent.  There might have been a teeny bit of noise, but I could only hear it in total silence.  While using the lens outside with all of the background noises of birds singing, cars driving past, lawn mowers working, etc., I heard nada, and focusing was definitely smooth.  Actually, focusing was smooth even under interior low light conditions.
  • Of course, neither my 50mm nor this new 40mm have image stabilization (IS), but the 40mm lens is so small and light that shake seems to be less of an issue.  Just about every image I took, the focus was spot-on from the first click to the last, with very few blurry images.

So what’s that little rubber cup I have attached to my cute little lens?  Well, when using a non-L lens, I generally don’t bother with any sort of filter unless I opt to use a circular polarizer (CPL). There is a school of thought out there that says filters are simply another layer of glass through which the lens must focus, thus distorting the original image and reducing its clarity.  For non-L lenses, I apply that school of thought.  For L-lenses, I like using the slim versions of filters for UV / protection and (in the case of the CPL) to eliminate vignetting for wide angle shots.  For the non-L lenses I prefer to simply use a lens hood as protection and shade from sun flare. With this lens, there is not – yet – a dedicated hood.  However, there are all sorts of lens hoods for 52mm filter threads, which is what I ended up ordering.  I purchased this little rubber wonderfor nostalgic reasons  in addition to price; I fondly remember during my high school years using a rubber lens hood. It works fine and I never have to remove it if I don’t wish to.   Plus, it takes up very little room in the camera bag.  It’s not exactly sturdy (like if you accidentally slammed your lens up against the wall), but it still does the job for me.

I’m sure you all want me to quit babbling and get to the meat of this post, which are comparison photos, right?    Ok, but first, you need to understand a few things.  I am not a technical person; no tech-speak here in this post.  I’m simply doing this review straight out of the box, from a Joe(sephine) the Photographer point of view.

Below are comparison photos of the 40mm STM f2.8 pancake lens and the 50mm USM f1.2L lens on a Canon 5D Mark II body. Now, I’m pretty sure some of you are saying “comparing those two lenses is like comparing apples to oranges, rather than comparing apples to apples.”  True, but it’s all I have to work with.

Normally, what I like to do with a Raw photo is start my editing in Lightroom 4, then export it to Adobe Photoshop CS5 and run the Auto Tone, do any other little artistic tweaks, and then the final Unsharp Mask.

However, for this comparison, the first photos  you initially see here are straight out of the cameras. No processing whatsoever except to import the Raw files into the computer and convert them to TIFs and then to low-res JPGS. Same settings for both lenses; yes, I know that although I am using the same brand and make of cameras, no two cameras of the same brand and make are ever totallyalike. Deal with it.

Low-Light Interior Shots – unedited

Canon 40mm pancake f2.8, ISO 200, shutter speed 1/30


Canon 50mm f2.8, ISO 200, shutter speed 1/30


– – – – – – – – – – – – – – – – – – – – – – –

Canon 40mm pancake f2.8, ISO 400, shutter speed 1/30


Canon 50mm f2.8, ISO 400, shutter speed 1/30


– – – – – – – – – – – – – – – – – – – – – – –

Canon 40mm pancake f2.8, ISO 640, shutter speed 1/30


Canon 50mm f2.8, ISO 640, shutter speed 1/30


Bokeh – unedited

Canon 40mm pancake f2.8, ISO 200, shutter speed 1/30


Canon 50mm f2.8, ISO 200, shutter speed 1/30


– – – – – – – – – – – – – – – – – – – – – – –

Canon 40mm pancake f2.8, ISO 400, shutter speed 1/30


Canon 50mm f2.8, ISO 400, shutter speed 1/30


– – – – – – – – – – – – – – – – – – – – – – –

Canon 40mm pancake f2.8, ISO 640, shutter speed 1/30


Canon 50mm f2.8, ISO 640, shutter speed 1/30


– – – – – – – – – – – – – – – – – – – – – – –

Exterior Shots – unedited

*Note:  For the exterior images, I had to keep changing the shutter speeds because the 50mm L-lens definitely lets in a little more light than the 40mm (as I originally surmised).  So, I wasn’t consistent with the speeds.  I did remain consistent with the aperture (f-stop) and the ISO.  All of the exterior images were taken hand held.

Canon 40mm pancake f5.6 ISO 250


Canon 50mm L f5.6 ISO 250


– – – – – – – – – – – – – – – – – – – – – – –

Canon 40mm pancake f5.6 ISO 250


Canon 50mm L f5.6 ISO 250


– – – – – – – – – – – – – – – – – – – – – – –

Canon 40mm pancake f5.6 ISO 250


Canon 50mm L f5.6 ISO 250


– – – – – – – – – – – – – – – – – – – – – – –

Canon 40mm pancake f5.6 ISO 250


Canon 50mm L f5.6 ISO 250


– – – – – – – – – – – – – – – – – – – – – – –

OK, so you’ve seen what the images from these lenses look like straight out of the camera with no processing. Now let’s see what some post-processing magic does to these shots, since I am one of those photographers who believes that just about every photo taken – no matter how perfect the in-camera exposure settings – has room for improvement with at least some post processing.

I imported these same Raw images into Lightroom 4, where I applied Lens Profile Correction, moved the Highlights slider all the way to the left, ran the Clarity slider up to between 30 – 50 and  on some of them, lightened the exposure.  Then I exported the results over as TIF files into Adobe Photoshop CS5.   For the images you see here, all the TIFs were ultimately saved as low-res JPGS after processing.

In CS5, I applied Auto Tone and/or Curves adjustment, then Unsharp Mask . That’s it.

*Note #1:  Lightroom 4 currently doesn’t have any sort of profile correction for the 40mm because this lens is so new.  I’m sure Adobe will eventually send out a patch for this.

*Note #2:  Looking at the exterior image 100% crops captured by the 50mm, I noticed sometimes they were not as sharp as they could/should be, and I attribute that to user error.  I’ve applied in-camera micro focus adjustment, and with a tripod, the 50mm images are beautifully sharp and smooth.  As mentioned above, though, I was not using a tripod for the exterior shots, my hands are small, and the 50mm lens is a “meaty” lens – especially compared to the teeny 40mm.

Here’s what the images look like now.

Interior – Edited

40mm pancake lens – edited original and 100% crop


9664_Edited_f28_ISO400_1-30_40mm CROP100pct

50mm L lens – edited original and 100% crop


0090_Edited_f28_ISO400_1-30_50mm CROP100pct

Bokeh – Edited

40mm pancake lens – edited original and 100% crop


9654_Edited_f28_ISO400_1-30_40mm CROP100pct

50mm L lens – edited original and 100% crop


0079_Edited_f28_ISO400_1-30_50mm CROP100pct

Exterior – Edited

40mm pancake lens – edited original and 100% crop

9584_Shrimp Plant Flower

9584_Shrimp Plant Flower_CROP100pct

50mm L lens – edited original and 100% crop



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40mm pancake lens – edited original and 100% crop



50mm L lens – edited original and 100% crop


9968_fig_edited_50mm CROP100pct

– – – – – – – – – – – – – – – – – – – – – – –

40mm pancake lens – edited original and 100% crop

9616_Wrought Iron

9616_Wrought Iron CROP100pct

50mm L lens – edited original and 100% crop


0017_WroughtIron_edited_50mm CROP100pct

– – – – – – – – – – – – – – – – – – – – – – –

40mm pancake lens – edited original and 100% crop


9611_Oleander CROP100pct

50mm L lens – edited original and 100% crop


0011_Oleander_edited_50mm CROP100pct

My concluding impressions:

  • I really really like this lens!  It’s a fun little lens! I’ve read other great reviews for this lens, and now I can add my own support.  It doesn’t let in as much light as a larger 50mm lens does, but it just requires a change in aperture, shutter speed, or ISO to remedy that issue.
  • It’s nice and light and easy to carry around on the camera.  Plus, it doesn’t call as much attention to the photographer as a larger lens might.  I don’t like to have attention called to myself when I am busy taking photos – it’s about my subject(s) and not about me.
  • I like the slightly wider view on my full-frame camera because I plan on using this lens not only as a walk-around lens but also (mainly) as a group/portrait lens.  This wider view means I can get more of a group in without having to back up as much.
  • I do wish they had made the lens a little faster (i.e. 1.8, 1.4 or 1.2 as opposed to 2.8).  Just a quibble though.  For me and my purposes, it’s still a decent low-light lens and I can increase the ISO if I need to.
  • It’s a damned sharp lens!  Canon actually did a great job with a non-L lens (I hate their kit lenses, and for a full-frame camera, it’s been L-lenses all the way for me….until now).
  • And finally, the price is right.

So there you have it:  my 2-cents worth of a review for the Canon 40mm STM f2.8 lens.  If you don’t feel like spending $200 right away, then just rent it for a few days (it’s a cheap rent) and decide if you want to have a lens like this in your camera bag.  Every lens I think about purchasing, I rent first (well, with the exception of this little gem).


Filed under lenses, Photography, Tests

13 responses to “Flat As A Pancake – The New Canon 40mm f2.8 STM Lens

  1. That was an excellent ‘Josephine the Photographer’ review, Rebecca. You made it all so understandable. So you would prefer the 40mm to the 35mm fixed focal length for group photos? I am curious, because I am thinking of upgrading from my kit lenses (I don’t have professional gear like you do – I have the Canon EOS 550D with the 18-55 and 55-250 mm zoom lenses).

    • Thanks for the nice comment. I’m always going to prefer the L lenses. So if I had the money, I would prefer to spend it on the 35mm L lens. However, on a limited budget, the 40mm lens is a very good lens. In general, any prime, L- or non-L, is going to be better than a zoom lens, and any L-lens is going to be better than a non-L lens. It all comes down to how much money you have / are willing to spend.

  2. Rebecca,

    ALl I have to say was “wow” and thank you for the education. i love that 40mm lenses. i shoot Nikon but can appreciate what you have done hear.

  3. I like your site. Thanks for the review, it’s very thorough! Do you happen to own an 85mm prime? I wonder how it directly compares…

  4. Thank you for the review. I’ve been using 2 pancake lenses on my small Olympus Pen system but this is the first opportunity for my Canon. Definitely worth a consideration.

  5. i bought a samyang 85mm lens put it on a 60d found it to amazing, but the only issue having to stand so far away from the subject, so I am considering this lens just not sure how it would compare to the quality of the samyang, I am doing the photos for the fashion business my partner owns as after using so many photographers and getting let down bit the bullet spent some money, you can really see the difference 🙂

  6. sorry mistyped email address this one on this post is correct 🙂

  7. This is the kind of comparison I’ve looking for. I’m wondering to get this 40mm when I own the 50m f/1.2 L, ok, also the 50mm f/1.8 II. The question is that I’ll be shooting at people and landscapes in places where I prefer not to be the point of attention, living together with a lot of people during a week, all day long with the camera on my shoulder.
    The focal lengh differencies and the IQ I see in your review are enough to take the decision. The other important aspects, size and weigth, I knew from the specs.

  8. Goes to show that good things come in small packages! It comes out with some brilliant results.

  9. Excellent review and I love the T-Rex shirt 😉

  10. Was searching articles about the 40mm. This one here is an interesting read.

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