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.
Table of Contents
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:
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.
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.
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.
Of course, if you have a high-resolution APS-C sensor like the recent 40MP one in the Fuji XT-5, then you get almost exactly the same pixel density as the newer 25MP micro four thirds sensor, and so this advantage of micro four thirds does not apply.
However, 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.
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.
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 from Nikon and Canon 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.
I don’t really want to write this next part, but I have to say it: although Nikon and Canon are pouring almost all their effort into mirrorless instead of DSLR, full-frame cameras are getting most of the attention.
For example, Nikon still does not have an APS-C camera on the level of its D500 APS-C DSLR. Sony’s APS-C cameras are solid but still far behind their full-frame options. Only Canon and Fuji have released wildlife-capable APS-C cameras in the form of the Canon R7 and the Fuji X-H2S.
Hopefully, APS-C will still be around for a while and Nikon will follow suit, 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 and even its Mark II successor out the door with a few new lenses added to the already huge collection for micro four thirds.
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, and the fact that I can also use the 500mm PF on my full-frame Z6.
Then look at camera bodies and the features that matter to you. Some micro four thirds cameras have amazing video features like the Panasonic GH6. 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, chosen with a view towards wildlife:
| Mount | Camera Example |
|---|---|
| Canon RF APS-C | Canon R7 (one of the best APS-C mirrorless) |
| Canon EF APS-C | Canon 90D |
| Sony E APS-C | Sony A6600, Sony A6400 |
| Nikon Z APS-C | Nikon Z50, Nikon Zfc |
| Nikon F APS-C | Nikon D500, Nikon D7500 |
| Fuji X APS-C | Fuji X-H2S (fast AF), Fuji X-T4 (generalist) |
| Micro four thirds | Panasonic G9 II, 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.
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.
Conclusion
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.
Thanks for this discussion Jason. I bought the OM-D EM 5 in 2013 as a small easy to carry around interchangeable lens camera and haven’t looked back. I bought the Pana/Leica 100-400 mm lens some years ago and that’s producd some excellent images when mounted on the EM 5. I’ve moved to the OM-D EM1 iiii and bought the Oly 12-100mm F4 – that is one heck of a lens!
I recently bought a Ricoh GR III to have as a pocket camera that can deliver excellent image quality.
The Oly MFT is great with the zoom lens which is where I think it excels. I love the GR III as a handy, take anywhere, high quality camera that you can throw in you bag or your pocket.
I can’t see where APS-C fits in. I think MFT will continue to have a place and certainly FF, but APS-C has me scratching my head. APS-C is stuck in the middle.
APS-C has its place because it’s cheaper and can use the longer lenses from Nikon that micro four thirds cannot match in terms of pixels on target. Like the 600mm PF.
I’ve just invested in MFT with olympus for my primary macro set up. The sheer weight difference and ability to focus stack in camera (and produce a jpg file for review) is a huge advantage over my Z8. The explanation of sensor size and pixels being more compact makes a lot of sense
This is really good article, thanks. You mention the pixel density of micro 4/3 being a big advantage, but don’t Fuji’s recent 40MP APS-C cameras now put them on the same footing? One other thing I’m interested in: are there any significant downsides to using APS-C lenses on full-frame bodies in crop mode (assuming a high MP sensor like Sony’s A7CR)? Does this give you a more versatile system?
Some examples of linear sensel densities (sensels per millimetre):
230 Nikon Z9
237 Nikon D500
266 Sony α7R V (60 MP)
299 OM SYSTEM OM‑1
313 Canon R7
329 FUJIFILM X-Trans CMOS 5 HR
Yes, that is true. I will update the article with this information.
APS-C lenses on FF bodies work fine. I do it myself sometimes. Of course, if you can afford a very high-density FF camera like the Sony A1, there is no downside to it except cost and weight.
That’s true for Sony and Nikon but not Canon. The EF-S lenses won’t mount of an EF body. Thanks
The only downside is that you’re throwing away lot of pixels for which you paid the price of a FF camera. OTOH there are some advantages.
If the camera has enough resolution in crop mode, you can avoid buying/carrying an APSC camera. This does make the system versatile.
With a model like A7R5, you can shoot full-frame 61MP when you need it, full-frame 26MP when you don’t need hi-res, or APSC 26MP for zoomed in view, which is still more than many 24MP APSC cameras.
You could shoot the full-frame hi-res and crop later for the same result but the advantage of shooting in crop mode is that you get smaller files and processing will be faster. You can also use smaller/lighter/cheaper APSC lenses for such use case. HTH.
Hi Jason, Super article, thanks. I think you may have overlooked something regarding the light-gathering capacity of the APS-C lens compared with Micro Four Thirds, and it’s something everyone forgets. The APS-C lens is larger and the rear element is further from the sensor. Therefore, the inverse square law comes into account, which reduces the amount of light reaching the sensor. So, any extra light-gathering capacity is lost. If I put any camera side by side with a Micro Four Thirds camera, set the ISO to 200, and set the aperture to be the same f-stop, then the shutter speed is equal.
Ivor wrote: “The APS-C lens is larger…”.
Because, for the same angle of view as the MFT, it requires a longer focal length (f); and to achieve the same f‑number (N) it requires a correspondingly larger entrance pupil diameter (D).
D = f/N
That’s the raison d’être of f‑numbers.
QUOTE f-number, Wikipedia
An f‑number is a measure of the light-gathering ability of an optical system such as a camera lens. It is calculated by dividing the system’s focal length by the diameter of the entrance pupil (“clear aperture”). The f‑number is also known as the focal ratio, f‑ratio, or f‑stop, and it is key in determining the depth of field, diffraction, and exposure of a photograph.
en.m.wikipedia.org/wiki/F-number
END OF QUOTE
Now, if we use the same f‑number, ISO, and shutter speed on each camera we have the same illuminance (total luminous flux incident on a surface, per unit area (lux)) and the same luminous exposure (lux seconds) of each sensor.
Note especially that illuminance is the luminous flux per unit area, therefore, the larger sensor receives more ‘light’ (lumens) in proportion to the ratio of the sensor areas, which is approximately:
370 mm² for APS‑C, DX
225 mm² for MFT
370/225 ≈ 1.64 times the number of lumens, which is equivalent to 0.72 f‑stop.
1 lux is 1 lumen per square metre, therefore
lumens = lux × square meters.
All of which confirms Jason’s statement: “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.”
Ivor continued: “…and the rear element is further from the sensor”.
The position of the rear element tells us nothing about the location of the exit pupil, which projects the scene onto the sensor. E.g., the rear element of the Nikon Z 135mm f/1.8 S is nearer to the sensor than the 16 mm Z‑mount flange focal distance.
Hi I do mainly wildlife and macro photography. Downsized recently to Nikon Z50 to save weight but now need something even smaller and lighter, looking at micro 4/3 system. Your article was interesting as you’ve used Nikon cameras. I agree with your comments about Nikon support for crop sensor bodies. I’m using my existing Nikon lenses with the FTZ adapter- am I correct in thinking that I can use other makes eg Laowa with either Panasonic or Olympus micro 4/3 cameras?
Many thanks for your interesting article.
Yes, that is correct! Many third-party manufacturers make third-party lenses for micro four thirds, including Laowa. In fact, I use the Laowa 50mm f/2.8X Macro myself, and you can also use both Olympus and Panasonic lenses also. An Olympus 100-400 on a micro four thirds body would certainly save you some weight over heavier, full-frame lenses.
Before you swtich though, consider the Nikon 400mm f/4.5. It’s almost the same weight as the Oly 100-400, but not as versatile and of course a bit more expensive (but also sharper).
I am thinking of moving to the MFT platform from Sony APSC. Sony seems to be focusing more on video with its Apsc line up. The three new lenses 11mm 1.8, 15mm 1.4 and the 10-20 f4 suggest that. Also, no Apsc, apart from Fuji offers comprehensive weather sealing. The Fuji XE4 with the 27mm f2.8, which I recently bought in a deal is a donkey when it comes to focusing. No comparison to my Sony a6400. Tried the Nikon Z5 recently! It was even slower to focus.
Jason!! What do you say about the tonality and colour depth difference between the MFT and Apsc? I am thinking of buying the EM5 MK3 used and mate it with the 20mm f1.4 pro lens. A solid weather sealed setup. No Apsc camera has the IPX 1 rating. Let alone IP53 on newer OM bodies and lenses. Is the noise much worse than the Sony? I am happy with the DR on my Sony a6400. I can recover a lot. I also like the portraits coming out of my Sigma 30 f1.4, which I shoot at f2 and above for portraits. Does the 20mm f1.4 render equally well or is worse in some ways?
Thanks
Great article.
Kunal
Thanks for this blog. Very helpful!
Came across this article while looking at pros/cons of G9/Z50.
I have to say this is one of the best articles I have read when it comes to M43/APSC. very well balanced with the pros and cons of both systems. Some articles would like to have the reader believe that the sensor size of M43 is SO much smaller that it really is against APSC. I have had a Z6 with 14-30,24-70F4 and F 70-300. Great camera, nice ergo’s but size/heft/weight after 300m I don’t like. Though the 80-400 lens was really nice, it’s not something I’d want to carry with me on a long hike. So have been looking at downsizing.
I’m an armature and mainly shoot landscapes and wildlife, do lots of hiking as well. So had narrowed it down the the G9 (8-18,12-60,50-200) or the Z50 with the 10-20(z18-140 or sigma 17-70 2.8-4)70-300. Both systems offer pretty much the same FF equivalent range. Though the Z50 kit is pretty much 1/2 the cost of the M43 kit. Cost savings for more lenses is always nice!
Z50
cons
Single cad slot, weather sealing (how good is it/does it actually have it – lens weather sealing) future of Z APSC bodies…D500 Z…will it happen. FTZ adapter, works well but still adapted lenses.
Pros
Marginally better low low, smaller body, access to F mount cheaper lenses.
G9
Cons
M43 and poor low light performance, lenses are more expensive (Leica DG ones)
Pros
features (time lapse/sensor shift / high res mode), ergonomics (Z50 are good/ prefer G9) lens quality with the DG Trio (8-18,12-60-50-200).
I’m leaning towards the G9 as I think the increased costs are worth it for the lenses / features. Sure it’s an older body, but it has had continued updates some of which have been pretty major, making it like a new camera almost.
good day friends! , I really like the Olympus for size and street photography. I have a question, Is it good for evening photos in the city? Or do you recommend aps-c? and is Micro Four Thirds suitable for portrait photography? I’m afraid of evening photos, thanks for your opinion and help.
To be honest a good, fast lens will help you a lot more than the sensor size. Micro four thirds will easily accomplish evening photos and portraits. And any recent Olympus camera also has great IBIS which will make static shots relatively painless.
Excellent article. Re your point about the big companies emphasizing FF and making FF cameras available at more reasonable prices while de-emphasizing APSC . . . It will be very interesting to see how that goes. I suspect a significant percentage of new FF users drawn to these more affordable FF cameras do not understand how big and heavy the lenses still are. You mentioned the Canon EF 11-24 F/4–that lens, the lens ALONE, weighs 1180g. I myself, a “one camera one lens” type who likes a single premiugrade fast normal prime, found that Nikon Z5 with the (incredible) Z 50mm f1.8 ALONE, weighs nearly as much as a Fuji “Texas Leica” 6X9 GW690iii medium format film camera.
IQ-wise for a stills junkie who doesn’t care about shooting fast motion, that is an awesome camera and lens combo. But for travel by plane and without a car . . . That won’t be coming along. One could carry a Nikon Z50 (or D3500 with the 35mm f1.8 prime attached), PLUS a Coolpix A 28mm equiv APSC, at less than the weight of just the Z5+Z50mm f1.8 S. Olympus E-M1 ii or iii with the new Zuiko 40mm equiv f1.4 PRO attached, plus a tiny PEN on the side with the Pana 40mm equiv 1.7 or the 12-32 pancake, both together also weight significantly less than Z5+Z50mm f1.8 S. If one forgoes the 2nd small camera, the weight/size difference moves from significant to dramatic.
So it will be interesting to see in two/three years, if those new FF buyers stick with it or migrate back to APSC/m43. I suspect plenty will move on once they’ve, er, got a load of the weight and size.