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.
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.
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 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. Along similar lines, 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 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.
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.
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.
I’m getting a bit tired of reports – almost always unsubstantiated – that Canon’s M mount is dead. Two years on, and my flagship M6 Mark II still sports the highest resolution APSC sensor on the market at 32.5 MP (!), 4K uncropped video, and 8 compact, image stabilized lenses. TBH, I don’t think I’ve ever had as much fun with a camera, which I use for still photography (street, birds, wildlife) and video (sports). I acknowledge legitimate concerns about gaps in the native EOS-M lens line-up, but Sigma’s new 16, 30, and 56 mm F1.4 primes are a brilliant addition, and Canon’s inexpensive EF to EFM adaptor provides _flawless_ performance when gaps remain (e.g. my 100-400 and 150-600 wildlife lenses). EOS-M cameras also remain crazy popular in Japan, which is Canon’s home market after all.
So despite these annoying click-bait headlines, Canon continues to release quality M models, like the M6 Mark II and the M50 Mark II. And while all good things eventually come to an end, I really don’t see them going anywhere soon.
PS: Ironically, the same commentators were also dismissing micro four thirds as dead until the latest releases from OM-1 and Panasonic, which suggests a bad batch of goat entrails. Having compared them with my M6 Mark II, I still prefer the APSC sensor in terms of low light/high ISO performance, resolution, and image quality, particularly if I need to crop the 32.5 MP image, as I often do with birds and wildlife.
I really don’t want to come across as too much of a fanboy, as I also used a Nikon Z50 mirrorless APSC. But it couldn’t compete with my Canon M6 Mark II for compact lens selection (the Z50 had only 2 lenses that took advantage of the smaller sensor) or high-speed burst rate ( the M6 II shoots 14 fps or 30 in cropped RAW vs 10 fps for the Z50), which were important for bird and wildlife shots.
You definitely don’t come across as a fanboy. And in the realm of wildlife, the Z50 is certainly very far from an ideal camera. The M6 Mark II sounds like a great camera!
You make some very good points there, and I probably should have been more careful about the way I talked about the M system. I have heard great things about it and it has some unique properties as you said. I appreciate your perspective and your detailing some of the advantages of it, such as its ability to work very well with adapters.
I shoot both full frame (Canon 5D IV) and micro four-thirds (Olympus OM-D EM1 Mk III, soon to be an OM-1). Viewed at 100% on a computer screen, I can tell the difference in quality; the Canon is cleaner, less noisy, with a greater dynamic range. But in a print? No. And I’ve printed up to 16×20 in each. So for me, though the Canon is objectively “better” in image quality, it isn’t meaningfully better.
I bought my first Olympus because I was going on a long international trip and wanted something lighter than the Canon. That trip, sadly, fell through, but I later brought the Olympus along as a backup system to photograph a chamber music festival I regularly document. The lighting there is challenging; think white jackets on stages with deep shadows. Light not always falling on faces. I discovered that the Olympus was actually better for the job than the Canon. Part of it was how quiet it is. I could shoot during pianissimo portions of performances, and during rehearsals, without bothering anyone. (That, of course, is less of an advantage now, with Canon and others going mirrorless.) I found the images from the Olympus, though noisier at 100% than the Canon images, were nonetheless often sharper than the Canon’s, because of the Olympus’s excellent image stabilization. (Of course, Canon has upped its game in this regard, too.) I was able to take handheld one-second-long exposures, for example, of people sitting in the hall during rehearsals, illuminated only by reflected light from the stage, and get very usable results. Though I had to be careful with exposures, I found the Olympus had enough dynamic range to capture the shadows while not blowing highlights on the male performers’ white jackets, and not underexposing the female performers in their evening gowns. I liked the color rendition better with the Olympus. And finally, the Olympus and its lenses were much lighter than my Canon system.
So, while the Canon produced less-noisy images, that was the main difference. And that difference was really only apparent during pixel peeping, not in prints. The Olympus, with its 20.4 MP files, used up a lot less (one-third, to be precise) of my disk storage than the 30 MP or so Canon, and certainly than one of the newer 40-60 MP offerings. The images processed faster in my somewhat antiquated computer. That all adds up over thousands of images. For me, the Olympus has turned out to be easier and more practical to use, and gives me everything I want.
As you point out in the article, most modern camera systems are pretty great. For most purposes, all of them produce usable, quality images. The “best” camera for any given application accordingly may not be the one with the lowest noise, the highest resolution, or the creamiest bokeh. It may instead be the one with good enough noise, good enough resolution, and good enough bokeh, that makes it easiest to get the image you want. It may be the one that’s good enough for the job while saving you a bundle on the gear itself. Sensor size, it turns out, is not everything.
Great points, and it was interesting to hear your opinion as someone who does events. Also, good luck with your OM-1. That should be a beast of a camera.
I agree 100%. I just traded my Nikon 105mm f2.8 VR S to MPB.
The reason is that I got the Olympus 60mm f2.8 macro. That lens is about 25% of the price, and 25% of the size compared to the Nikon lens. I am sure that a lab test would prove the Nikon lens to be superior, but he Olympus lens take fantastic images also and they are perfectly fine for me.
Further, I get many more good shots with it. The small size makes it much easier to i.e. follow a hoover fly from flower to flower. So, for me, the Nikon may win in a lab test or on a tripod with a photo box. But in outdoor handheld use the Olympus wins hands down. I traded the Nikon for another lens because I knew I wouldn’t use it much anymore.
I think macro is a great use case for micro four thirds. That 60mm is an outstanding lens. I have the Laowa 50mm macro and I can’t believe how small it is!
Just shoot the Sony 61mp a7Riv. Your APS-C crop mode, or crop in post, will have 26mp & w/o any AA filter. If you crop to m4/3 size you’re still capturing about as much detail as does a 20mp m4/3 sensor. You’ll be using a camera with full controls, good ergonomics. My Tamron f2.8 70-180 in crop mode gives the fov of a 105-270, and at f/2.8 and weighing only around 850g. My Tamron 150-500 functions in crop mode as would an FF 225-750. After I bought the a7Riv my a6500 became superfluous and was sold. In every circumstance using the a7Riv in crop mode was more satisfactory.
That is certainly a great option for pixel density! The only real downside is lens size, which is sometimes smaller on micro four thirds. However, it must also be amazing to use the full 61mp as well :)
Your statement would be correct if your lens would resolve full 61mp (technically it should be 80mp), but it doesn’t, so your theoretical statement is a bit flawed…
I know because i also use a7rV and OM-1, and there’s no lens that i cropped 2x, that would match OM-1’s uncropped image details… not even close if you compare ”same-tier” lenses…
When you’ll use m4/3 in practice, you’ll see what i’m talking about…