What’s better: micro four thirds or APS-C? Are these two sensor formats at odds? Could any question spark an internet argument more quickly than comparing sensor sizes? There is no doubt that there are advantages and disadvantages of each. Today, I would like to talk about why I (gasp) choose to shoot with both formats. And perhaps surprisingly, my reasons have very little to do with sensor size.
A Little Bit About the Formats
Of course, the most obvious difference between APS-C and micro four thirds is sensor size. You can get an idea for this difference from this image, with a full-frame sensor included for comparison:
To-scale representation of three sensor formats
As you can see, the difference between APS-C and micro four thirds is a bit less than the difference between full frame an APS-C. In fact, the area of an APS-C sensor is about 1.6 times the area of a micro four thirds sensor, albeit with an aspect ratio of 3:2 for APS-C rather than 4:3 for micro four thirds.
Not all APS-C sensors are the same size, either. Canon stands out by using a very slightly smaller sensor in their APS-C DSLRs compared to Nikon, Pentax, and Fuji, and I encourage you to read the article What is Crop Factor? for more information.
Why I Use Both Micro Four Thirds and APS-C
When I became serious about bird photography, I got the Nikon D500. It’s a Nikon DX camera, which is Nikon’s label for APS-C sensors. (See Nikon DX vs Nikon FX.) This camera makes a near-perfect birding combination with the 500mm f/5.6 PF lens.
Nikon D500 + 500mm PF f/5.6 @ 500mm, ISO 125, 1/4000, f/5.6
However, I also had interest in a few other areas like videography and insect photography that I felt would be better with a second camera. I considered quite a few options, including Fuji X and Nikon Z, but I settled on a micro four thirds camera instead. Specifically, I chose the Panasonic G9 thanks to its video features and wide range of lenses.
Benefits of Micro Four Thirds
There are two companies that make micro four thirds cameras today: Panasonic and OM System (formerly Olympus). Both provide reasonably-priced models that are typically packed with features.
For example, Panasonic has an emphasis on video. The G9, GH5/GH5II and GH6 all offer 10-bit internal 4K video recording and adjustable zebras – specifications that are usually found only on more expensive cameras. Some Panasonic cameras also support other features like anamorphic lenses and 1080p footage at 300 FPS, which even the top-end full-frame mirrorless cameras generally lack.
As for OM System/Olympus, they have been putting a lot of effort into computational photography and unique features not found on other cameras today. This includes a feature called Pro Capture (AKA a back-in-time buffer), which takes a constant buffer of photos and lets you save images taken slightly before you depressed the shutter button. Combined with fast autofocus and good wildlife photography lenses (like the Olympus 150-400mm f/4.5 or Olympus 300 f/4), these cameras make attractive wildlife setups, especially for the price.
Panasonic G9 + Olympus 40-150 f/4-5.6 @ 58mm, ISO 250, 1/125, f/6.3
Another feature of micro four thirds cameras is the sensor aspect ratio of 4:3. This might not seem terribly important, but I enjoy composing vertically more with micro four thirds, and I have recently heard a few other photographers say the same. APS-C has always seemed a little thin in the vertical orientation. So, the 4:3 ratio can be intriguing and provide new compositional ideas.
Micro four thirds cameras are also very pixel-dense, with the most common resolution being 20MP. Even though that’s lower than the usual 24 megapixel sensor of APS-C cameras, it’s a greater density of pixels because they’re all crammed into a smaller sensor. As a result, it’s easier to put more pixels on small or distant subjects with micro four thirds, like in wildlife and macro photography.
Also, since micro four thirds lenses have to cover a smaller sensor size, they are typically smaller than the lenses for larger formats. Many micro four thirds cameras are also small themselves. The result is that the system can be made pretty compact while still providing high levels of image quality.
Panasonic G9 + Laowa 50mm f/2.8 2X Macro @ 50mm, ISO 200, 1/640, f/2.8
Benefits of APS-C
Because the sensor area of APS-C is 1.6 times the area of the micro four thirds sensor, it provides 1.6 times more total light gathering capability, or about 0.7 stops. Therefore, in many cases, APS-C will provide a bit of a performance advantage over micro four thirds. At the same ISO, for example, you will see about 2/3 stop better noise performance on APS-C.
Nikon D500 + 500mm PF f/5.6 @ 500mm, ISO 720, 1/2500, f/5.6
However, this is hardly a huge advantage, and it doesn’t apply all the time. If you want to magnify a distant subject, for example, the higher pixel density of micro four thirds will give you better results in the end. Furthermore, you may be able to use a micro four thirds lens with a larger maximum aperture value to negate the advantage of APS-C. Given the many differences between the two systems as a whole, I do not believe sensor size itself is a huge advantage of APS-C.
Instead, it makes more sense to focus on the practical differences between the two, such as lens availability and camera body features. For example, for wildlife photography, APS-C cameras have access to several supertelephoto designs like the 500 f/4, 500mm f/5.6 PF (Nikon), 600 f/4, and 800 f/5.6. If your ultimate goal is to shoot with such primes, an APS-C camera is a more logical choice compared to micro four thirds.
Another advantage of the APS-C cameras from Nikon, Canon, Sony, and Pentax, is that they use the same mount as their full-frame counterparts. Thus, if you want to shoot with such a brand’s full-frame cameras as well, it makes more sense to stick with APS-C and interchange your lenses between your different cameras.
Which One Should You Use?
There are a few points I recommend considering before you settle on either APS-C or micro four thirds.
First, think about lens compatibility. The two micro four thirds companies – Panasonic and OM System – share a lens mount. If you start out with one company and buy a bunch of lenses, you can later get a camera from the other company and still use your existing glass. APS-C doesn’t work that way. There are several different APS-C formats, including Canon EF, Canon EF-M, Fuji X, Nikon F, Nikon Z, Sony E, and Pentax K. Lenses cannot be swapped between these formats without an additional, expensive adapter (and sometimes not even then).
This doesn’t mean APS-C is a bad choice, but it does mean you need to put more thought into what brand and APS-C format you buy. Make sure the company you’re considering has a lineup of lenses that works for your needs. For example, Nikon and Canon both have a great set of supertelephoto lenses to choose from, but their APS-C choices for lightweight, wide-angle prime lenses falls behind that of Fuji.
Nikon D500 + 500mm PF f/5.6 @ 500mm, ISO 3600, 1/400, f/5.6
I don’t really want to write this next part, but I have to say it: With the big companies, APS-C sadly has an uncertain future. Now that Nikon and Canon are pouring almost all their effort into mirrorless instead of DSLR, it seems that full frame sensors are in vogue and not APS-C. Nikon at least has the Z50 and Zfc APS-C mirrorless cameras, but neither are at the level of their D500 APS-C DSLR. Along similar lines, Sony’s APS-C cameras are solid but still far behind their full-frame options. Meanwhile, Canon does not yet have a single APS-C camera in their newest R-mount, and they’ve basically left their previous EF-mount and M-mount lineups to die.
Is it possible that one of the big players will release an APS-C mirrorless camera that has most of the features and speed of their flagships, like the Nikon D500 was to the Nikon D5? Yes, but so far there is no evidence of that – and believe me, I have scoured every interview for some hope of that, because I enjoy the APS-C format a lot. I think APS-C will still be around for a while, but I doubt we will we ever again see the attention that APS-C once received from Canon and Nikon, who at one time produced models for every situation.
On the other hand, micro four thirds is actively developed. Panasonic just released the amazing GH6, which is one of the most capable video cameras on the market today and certainly the best video camera per dollar. And despite gloomy predictions, OM System got the OM-1 out the door with a few new lenses added to the already huge collection for micro four thirds.
Panasonic G9 + Laowa 50mm f/2.8 2X Macro @ 50mm, ISO 2500, 1/125, f/6.3
With these points in mind, there is a clear strategy to decide which format is for you. First, look at lenses. What brands and formats have the lenses that you need for your type of photography? For me, Nikon’s 500mm PF is practically the main reason I got into Nikon DX cameras at all.
Then look at camera bodies and the features that matter to you. No APS-C body can come close to the video features on the Panasonic GH6 or some of the computational photography features found on Olympus cameras. At the same time, the ergonomics of Fuji’s APS-C cameras are hard to beat, and if you want a DSLR instead of mirrorless (such as for the optical viewfinder), APS-C is the way to go.
Finally, it’s worth mentioning that all modern camera systems are pretty great, so outside of some specialist needs, it’s hard to go wrong. But just in case you still need some help, here is a small chart with some starting points of my favorite cameras from each mount:MountCamera ExampleCanon EF APS-CCanon 90DSony E APS-CSony A6400, Sony A6100Nikon Z APS-CNikon Z50, Nikon ZfcNikon F APS-CNikon D500, Nikon D7500Fuji X APS-CFuji XT4 / Fuji XT30 IIMicro four thirdsPanasonic G9, Panasonic GH6, OM System OM1, Olympus OM-D E-M5 Mark III
Finally, I would like to add a small personal note. Of all the cameras I have used, the micro four thirds Panasonic G9 is one of the most fun because its physical layout and firmware are really well done. Other photographers say similar things about Fuji’s APS-C cameras. Therefore, I recommend just holding some possible cameras at a brick and mortar camera store, because one model may just stick out as something really special when it’s in your hands.
What About Full Frame?
Although this article is not about full-frame, I think it’s wise to mention it. Nikon, Canon, and Sony have all been pouring most of their recent efforts into making full frame cameras, including plenty that are very affordable like the Nikon Z5 and Canon EOS RP. It was historically the case that full frame was more expensive, but that’s no longer necessarily true.
NIKON Z6 + 500mm f/5.6 PF @ 500mm, ISO 800, 1/800, f/5.6
Full-frame certainly has other advantages as well, such as the availability of some very wide lenses like the Canon EF 11-24mm f/4L, which provide an insanely wide field of view on a full-frame camera. It allows for shallower depth of field with lenses like Canon’s 85mm f/1.2. Full frame also tends to have better image quality, especially for shooting at very high ISO values, or for landscape photography from a tripod.
I encourage you to read Sensor Crop Factors and Equivalence for more details on the technical differences between these camera sensor sizes. At the end of the day, it might come down to a choice between a lower-end full frame camera for better image quality, versus a higher-end APS-C or micro four thirds camera for better autofocus, handling, and advanced features.
Both micro four thirds and APS-C are compelling sensor formats. Moreover, as we have seen, both have different strengths which are mostly concerned with overall brand ecosystems rather than sensor size. Although it can be hard to get a handle on all the information about different cameras, I hope you have a bit of a better idea on which to choose. If you have any further questions for your specific situation, I would be happy to respond in the comments.