Canon EF-s 24 2.8 STM

Pancake Lens for APS-C EOS

Peter Kun Frary



The EF-s 24 2.8 STM was released Fall 2014 and joins the EF 40 2.8 STM as one of two pancake lenses in Canon's lineup. Although appearance is nearly identical to the EF 40 2.8 STM, the mount is APS-C only, e.g., Rebel and 70D, and does not fit full-frame cameras such as the 5D MKIII or 6D. Here's my thoughts on the EF-s 24 2.8 STM after shooting with it over the holidays.

Raindrops on Moonroof | EOS SL1 & EF-s 24 2.8 STM (F2.8)

EF-s 24 2.8 STM | Sharp and wee (image courtesy Canon)


This six-element design is housed in a protrusion barely larger than a body cap, hence the pancake moniker. Mounted on a Rebel SL1, the entire kit slides in my coat pocket and is so light it feels like I forgot the lens! Build quality is great: metal mount, sturdy plastics and attractive industrial satin finish.

EF-s 24 2.8 STM & Rebel SL1 | Fits in a coat pocket or purse

Auto Focus

Auto focus is more sure-footed and peppy than the EF 40 2.8 STM. While AF is generally reliable and accurate, it misses a little more often than my USM primes, e.g., EF 24 2.8 IS USM, mainly when refocusing on the same point in a subsequent photo. The EF 40 2.8 STM is worse in this regard, so Canon seems to be refining the STM motor's controlling software.

East Fremont Mural | EOS SL1 & EF-s 24 2.8 STM, F2.8, 1/64, ISO 1600

Focus is almost inaudible—a pianissimo "sheeek"—but is picked up by the SL1's built-in mic during quiet video clips. Workarounds include use of an external mic, outboard audio recorders (what I do), focusing before shooting or disabling movie servo. However, focus is buttery smooth and ideal for touchscreen pulls during video.

It can focus as near as 6 inches, nipping at the coattails of the macro range. Subject distance is too close to easily illuminate flat art or small products, but I've used it for tight framing of LCD screens.

Canon 80D LCD screen | EOS 70D & EF-s 24 2.8 STM, F3.5

Manual focus is "focus-by-wire"; i.e., the MF ring isn't mechanically coupled to the lens and is merely a switch for activating focus. Manual focus is smooth and accurate, albeit slow. The nested barrel extends during focus, getting slightly longer at macro distances. It also features FTM (Full-Time Manual), i.e., ability to override AF without flipping a switch. The gotcha is FTM is only active when the shutter button is half depressed.

Pearl Harbor Vista | EOS SL1 & EF-s 24 2.8 STM, F8, 1/250, ISO100

Image Quality

The slightly wide view coverage of 24mm on APS-C—equivalent in coverage to 38mm on full frame—is ideal for street shooting, landscapes and candids. I love shooting wide open at F2.8 and this lens delivers tack sharp images. Corners are slightly softer but improve when stopped down, nearly equalizing with the center by F4.0.

Guitar Student Fauna | EOS 70D & EF-s 24 2.8 STM

Light falloff (vignetting) is pronounced at F2.8, nearly two stops below center brightness, but fades by F4. Although light falloff is considered a drawback, the natural vignette is pleasing for portraits and nostalgic landscapes. The image below, shot at F2.8, illustrates typical light falloff in the corners.

Ritter Gig Bag | EOS SL1 & EF-s 24 2.8 STM

Defocused areas at F2.8 have a smooth swirl to them (bokeh), albeit not as pronounced as longer lenses. There is slight chromatic aberration (CA), but only in high contrast light at frame edges, e.g., tree branches against a bright sky.

Peace | EOS SL1 & EF-s 24 2.8 STM (F2.8)

Lens Hood

The dedicated hood that fits both the EF 40 2.8 STM and EF-s 24 2.8 STM is the Canon ES-52: basically a 52mm aluminum filter ring around a disk with a hole in the center. It provides almost no shading or protection. If you don't mind spoiling the pancake vibe, a 52mm thread generic metal hood for 28 to 35mm coverage works better.

Canon ES-52 Lens Hood (image courtesy Canon)

Jeans | EOS SL1 & EF-s 24 2.8 STM, F2.8, 1/320, ISO 100

Final Blurb

Normally a Benjamin and a half doesn't buy much in terms of optics but the EF-s 24 2.8 STM lens is an exception: made well, renders beautiful images and is sharp wide open at F2.8. I also own the EF 24 2.8 IS USM and must say, the EF-s 24 2.8 STM, at less than one third the price is just as sharp and vibrant in color clarity. Of course, the more expensive lens also works on full frame cameras, has IS and focuses much faster.

I take the EF-s 24 2.8 STM and my SL1 everywhere and the tiny form factor allows stealth in bars, casinos, restaurants, markets and streets, basically anyplace where hoisting a big zoom draws unwanted attention. Carrying it with me when not on a shoot often leads to whimsical and off the cuff images. Highly recommended!

Finally, please help support this website by purchasing this lens at Amazon.


Focal Length: 24mm

Aperture: F2.8 to 22

Lens Construction: 6 elements in 5 groups

Min. Focusing Distance: 0.52 ft./0.16m

Maximum Magnification: .17x

Angle of View (Diagonal): 59°10' (APS-C)

No. of Diaphragm Blades: 7

Filter Size: 52mm

Diameter & Length: 2.7 x 0.9 inch / 68.2 x 22.8mm

Weight: 4.4oz / 125g

Included Accessories: lens caps

Cost: $149.99 (MAP)

Fallen Palm | Honolulu | EOS Rebel SL1 & EF-s 24 2.8 STM

01/06/2015 | Revised 01/08/2017

©Copyright 2015-17 by Peter Kun Frary | All Rights Reserved

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