Answering the Question – Canon 5D Mark III versus Olympus OM-D E-M1

A little while back I asked myself on this blog if I should keep my Canon 5D Mark III after I got my Olympus OM-D E-M1. In short, I was wondering if it was worthwhile keeping the Canon if the Olympus is easier to carry and can deliver the kind of experience and results the Canon could.

Olympus tells me I was one of a lucky handful that got their E-M1 early and so I have had little more than a week to seek the answer to my question.

A week isn’t very long, but in the that week I have tested the areas that matter most to me, which are resolution, performance in the studio, low light and autofocus. Like in my other posts, I have tested in situations that are similar to the ones I normally shoot in. These tests are thus not exhaustive. Also. I haven’t shot any video.

I won’t discuss some glaring differences between the two cameras, such as price, weight, bulk , stabilization and availability of lenses and accessories. I assume my readers are well aware of those considerations.

Neither am I sharing my pure test shots with you. They’re boring. Plus, I think any blog can only host a limited number of pictures of puppies or passing cars.

Let’s go.



 Olympus OM-D E-M1

The Canon wins, no question about it. I used my better Canon lenses and my better Olympus lenses and in all cases the files of the Canon are markedly sharper at 100% on my monitor. In model photography that doesn’t matter that much, because there’s only so much sharpness you want, but in landscapes it matters. Tree trunks, fall leaves and rock formations resolve better on the full-frame Canon sensor than on the much smaller Olympus MFT sensor.

How much better? This is where push comes to shove. On small prints or JPEGs, you can’t tell the difference, but I hope you don’t buy these kinds of cameras if all you want to make are small prints or show little pictures on the web. On 13×19 prints the difference is hard to tell from a normal viewing distance. When looking closely, there’s a bit more resolution in a picture of a forest line, but no discernible difference in a portrait. I can’t print larger than 13×19 at home, so I will have to order a few larger prints to see how much the difference matters in the real world.

Low Light


Canon 5D Mark III

Again, the Canon wins. The Olympus does well in low light, but the Canon shows less noise. With the Canon, you have more leeway. In most circumstances the Olympus will serve you well in low light, but when there’s an extra challenge or you plan to shoot quite a bit in dimly-lit environments, you need the Canon.


Another win for Canon, but not necessarily a deal breaker for the Olympus.

Single Auto Focus is fast in flawless on both cameras. I don’t own any Olympus Four-Thirds lenses, so I can’t speak for those, but the MFT lenses I own all focused very fast and were spot on. The Canon, of course, was without problems in this regard as well.

Continuous Auto Focus is where the differences show up, as was to be expected. The Canon locks on quicker and stays with the subject more consistently than the Olympus. The Canon also is quicker to find the subject again after one or two shots get out of focus. Both cameras become weaker in this regard as the subject gets closer, but that’s to be expected.

On both cameras you can limit the focus points to certain segments and this improves the speed and accuracy as long as you manage to keep your subject within the chosen area.

Still, the Olympus does a good job. If you’re shooting sports in low light and from relative close distances, the Canon is your better bet. If you’re working pretty far away and have some leeway with your aperture, the Olympus performs admirably.

Personally, since my kids aren’t running through the house anymore and I don’t shoot sports, the autofocus on the Olympus is plenty good for me.

With focus tracking, a feature the Olympus offers but the Canon doesn’t, you focus on a subject and the focus point in theory stays with the subject as it moves through the frame or as you move the frame.

In practice, I found that the camera loses tracking on a pedestrian if another pedestrian crosses the first pedestrian’s path. The tracking jumped over to the second person. When tracking our new puppy in the garden, the camera tracked but the focus point shifted to the side of the dog where the fur had the most contrast instead of staying on the dog’s head. There might be occassions where it comes in handy, but I don’t see myself using it.

Studio Work


Olympus OM-D E-M1

They’re both perfectly fine. I’d prefer the Canon, but merely because in a studio I don’t have to lug my gear around and I might as well use the camera with the higher resolution. Even though a model’s face doesn’t need to be completely sharp, you want maximum sharpness in the eyes. But I would have no problem only using the Olympus in a model shoot.


The Canon clearly beats the Olympus. As it should.

But the question was whether I could ditch my Canon and live without full frame.

I don’t think so, actually. There are times when it’s nice to get the extra resolution that a full-frame camera offers or to be able to get maximum image quality in low light. It’s also good to have a camera that can do it all, or almost all, as the Canon 5DIII can.

If you’re shooting action, I’d surely keep the Canon. MFT isn’t there yet.


The Mystery Somewhat Explained – Olympus OM-D E-M1

But I am looking at DSLRs in a new way. I no longer regard them as my go-to gear, like I have done ever since I started dabbling in photography. I now regard my 5D as a kind of poor man’s medium format, a system I’ll use when I really need it and don’t mind carrying it for that purpose. On paper, it actually makes sense to then get the most out of full-frame and get the Nikon D800(e) with even more megapixels than the Canon. In practice, the quality difference between the two seems relatively small.

This shift in thinking about full-frame DSLRs now leads to a rethink in what lenses I actually need. I have a whole range of lenses for the Olympus, because that’s the system I’ll use the most under different circumstances.

But for the Canon, I only need lenses that perform well during landscape shooting, on model shoots and in low light. This problably means that I will sell some of my Canon lenses and maybe replace them with  Zeiss lenses.

For you, the answer might be different. If I were to shoot weddings, I’d have to learn more about Olympus’ flash performance, for example. For sports, I’d stick with the Canon. Blowing up images beyond 13×19, also the Canon.


Canon 5D Mark III

Related posts:

Olympus OM-D E-M1 Review

Quick Update on the Olympus OM-D E-M1 Review

Olympus OM-D E-M1 Review – Ditch the E-M5?

Keep the Canon 5D Mark III After the Olympus OM-D E-M1 Arrives?


Cameras mentioned in this post (affiliate links):


Olympus OM-D E-M1 Mirrorless Micro Four Thirds Digital Camera (Body Only)
Canon EOS 5D Mark III DSLR Camera (Body Only)


Olympus OM-D E-M1
Canon EOS 5D Mark III


  1. You wrote “the files of the Canon are markedly sharper at 100% on my monitor”.

    My feeling has always been that if you have to view at 100% to detect the difference, it is immaterial. People don’t view photographs that way. Regular viewers don’t walk up to a large print and stare at the dots with a magnifying glass, they stand back and take in the entire image. And the larger the print, the farther back they stand.

    If you can see the difference in detail in a 20×24 print, or on the full image on a 32″ monitor, from normal viewing distance, then I’ll agree the M1 isn’t quite good enough. But I’ll be very surprised if you can.

    • I agree. That’s why I made the prints and added the information about them. On most normal sized prints you wouldn’t see the difference. It’s only when you print really large that the E-M1 will look less sharp than the 5D Mark III.

      • But my point is that with big prints, you stand further away to view them, so I’d be very surprised if you can tell the difference even then.

        • Yes, you’re right. But when you test, you look closer than a normal viewer would. That’s all I’m saying.

          • Don’t look too close John, you might get lost in those pixels. The M1 produces excellent quality files (and so does any recent Micro Four Thirds camera). You can print really big, big enough for most uses. I use the MFT system because it’s so much more portable. It’s a joy to use too. Those little Olympus cameras are responsive and precise and the in body stabilization is just amazing. Something I wouldn’t want to give up for slightly higher resolution files with a little better dynamic range. Technology gets better and better and I wonder what the next generation MFT sensors will bring us. Perfectly fine as it is, and the fact that it can only get better is exciting.

    • And of course monitors display at 72DPI and prints at 300dpi usually, so the images always look worse on the monitor. I have A1 and A2 prints in an exhibition made with Lumix GH3 files which are as good or better than others in the exhibition shot with my Nikon D3s.

  2. Steve Philipp says:

    “I used my better Canon lenses and my better Olympus lenses” contradicts “I don’t own any Olympus Four-Thirds lenses, so I can’t speak for those”. There is a big difference.

    • I don’t see why it contradicts each other. I said ‘my better’ lenses, not the ‘the better’ lenses.

      • He is saying that you didnt use any of the HG/SHG 4/3rds lenses to compare against the better Canon lenses.. the HG and SHG 4/3rds glass from Olympus may make a big difference in IQ and sharpness as compared to what m 4/3rds you may have used, I am not sure what m4/3rds lenses you used my HG and SHG 4/3rds lenses are better in IQ when used on my EM5 with the 12-50 and 75-300 anyway, but that is to be expected, I dont have any higher grade m4/3rds to compare against the 4/3rds lenses myself..

        • I should indeed have mentioned the lenses I used. The key resolution tests were done with Canon primes and L lenses versus Olympus MFT primes, such as the excellent 12mm, 45mm and 75mm.

  3. ibluetooth says:

    Hi, just a quick question…let’s say you did have younger kids and you wanted a camera to photograph them playing, dance recitals and all of the other fun stuff – some low light, some outdoors etc. PS, I’m a notorious cropper – my technique is pretty horrible and I rarely ever fill the frame on the original shot :-( Which system would you pick?

  4. Andy Elliott says:

    I have the 5D3 and several L-primes but I’m still getting the E-M1. It’s just too nice.

  5. Few comments from a photographer that takes pictures since 1974 and spent in his life an amount of money in photo gear that I cannot comfortably admit in a public site…
    Webites like DPReview generally and stupidly define photographers like me as ‘advanced/enthusiast amateur’ or ‘semi pro’, whatever this means :)

    Okay, I know that people don’t print anymore, but if you don’t print you don’t need 24 Mpixels: the monitors we use generally are no more than 2 Mpixel (1920×1080), what’s the point to buy a 24 Mpixel camera if the best you can see is a 2 Mpixel picture??
    The biggest advantage of 24 or 36 Mpixels is the possibility to crop more aggressively.
    In my experience, 16Mpixels with a sharp lens are enough for ANY print.
    I print with an Epson 3880 both FF (24 and 36 Mp) and E-M5 pictures on 16″x23″ and I cannot see the difference if I look at the print from a distance that is enough to see the whole picture.
    If you need to get so close to the print to see the difference between 16 and 24 Mp, it means that you are not looking at the picture, you are looking at the pixels.

    I don’t have an E-M1 so don’t know how it works in C-AF.
    I’m pretty sure that Canon C-AF is better, but in S-AF I found last generation m4/3 cameras (E-p5 and E-M5) as fast as (or even faster than) Canon/Nikon DSRLs.
    Try a D600/D800 with any zoom that is not in the top line or any Nikon prime, like 85 f1.4: they will take ages to focus compared to last generations m4/3 cameras and lenses.
    Where m4/3 wins hands down in S-AF compared to DSLR is precision: finally the typical reflex back or front focus are gone forever with mirrorless.

    Low light:
    For sure in absolute terms the FF sensors wins for a stop or two.
    But after using 4/3 and m4/3 in the same situation with FF cameras, I found so many situations where the lower noise of FF sensors is not enough to counterbalance the smaller depth of fields.
    I cannot count how many times I was able to take a shot at ISO 200/400 with m4/3 and lens wide opew at f2.8 while I was obliged to shot with a FF at 800/1600 and f 5.6/f8 just to get enough depth of field.
    Try to make group portraits with a FF camera, you need to stop down to f5.6/f8 just to get all the people sharp.
    In these situations you need high ISO to avoid blurred pictures, so high that the FF noise advantage is completely useless.
    With m4/3 you can easily get bigger depth of field at f2/f2.8.
    With FF you gain one or two stops of noise but too many times you loose them by stopping down the lens to get the whole scene sharp and focused.
    In addition the current FF lenses more often than not are very soft wide open, while almost all 4/3 and m4/3 lenses are very sharp at F2/f2.8.
    Please consider also that current Olympus IBIS system is so effective that I can take sharp picture with wide angle lens without mono or tripod at 200 ISO and 1/4″ or 1/2″ shutter speed or 1.6″ or 2″ with elbows on a table: try to do it with a wide angle on FF, you need to go at least to ISO 3200 to get a safe shutter speed.
    If you add no stabilization on many FF lenses, soft FF lenses wide open, too thin depth of field, you will find that m4/3 pictures very often have LESS noise than FF ones.

    After owning and trying so many different cameras, from compacts to APS-C, from 4/3 to FFs, I think that current generation of m4/3 cameras has reached a sweet point, where the image quality is more than enough for 98% of my shots and 100% of my prints, but wins hands down in term of weight and discretion.
    100 Mpx and clean 25600 ISO are useless if the camera stays at home because I cannot load on airplanes, I cannot go around the city with a gigantic backpack that screams $$$, I cannot take candid with a white big gun aimed in face of people, I cannot walk for hour without sweating like a workhorse.

    The best cameras are the ones you can use always and everywhere: since I got an E-M5, my FF gear is rusting and dusting at home…

    • You make a good argument for m4/3. I was considering switching from my E-PL5 to a 5DIII, but I think you have just changed my mind. Nice original review also.

    • I agree with most of these points. I currently own a 5dmk2, Olympus Ep5 and recently a Panasonic GX7 .



      * I am not talking about professional photography here, I am talking about what is good for most consumers and amateur photographers, even journalists i.e. most of the market. A professional photographer would naturally just buy whatever kit helps him/her bring in most money whether it be $5000 DSLR or $500 Go Pro. i.e. The exact tool for the exact job. There may be some effects that can only be done with a D3x so a D3x makes complete sense.

      — ——— ————– ————- ————- ————–
      However, in general :-

      People/reviewers often speak of aperture equivalence and “blurring out backgrounds as if this is the most important thing in photography, completely forgetting that you need to stop down FF lenses to get the required sharpness. I have found my Panasonic 25mm 1.4 is better wide open that it’s Canon counterparts at F2.0. Also, it is unmatched in terms of sharpness at F2.8, I cannot find a Canon prime in the Panasonic’s price range that can compete with it, you need something twice as expensive to be realistic.

      The point is reviewers just point to “blurring out backgrounds” I recently recently read “obliterating backgrounds!” on another review site and it’s written as if to say that lack of depth of field is universally meant to be a positive, when in fact the opposite is true in most cases. In fact, the small aperture/sensor and large depth of field setup of mobile phone cameras is what has allowed these cameras to produce very sharp images and completely dissolve the point and shoot camera market.

      In practical terms the advanced stabilisation system in the Olympus EP5/OM-D/EM-1 system allows for better low performance in practice than my 5dmk2. The 5d may have 2 stops of sensor performance on paper (in theory, for me its less in practice) but the EP-5 has around 2-3 stops of performance due to its stabilizer and sharper optics, so in the end the EP5 wins out, however you never read this on a review site all you are told by reviewers is bigger sensor = always better.

      The contrast detect (always described as as “only has contrast detect AF” by popular camera sites on the GX7 is faster and more accurate than the 5dmk2 by a long way. The reason that Olympus,Panasonic , Sony have stuck with “only” CD AF is because obviously there is headroom to improve performance and this has been the case since first generation of mirror-less cameras. PD autofocus is only superior for tracking subjects and some implementations (such as high end 3K DSLRs) are far better than others such as mid range DSLRs which barely work at all.

  6. I have to say that a full frame DSLR and 4/3 camera are apples and oranges. Either can be great, depending one what you want it for. I have been a photographer since the 80s and have mostly been a Cannonista. That said, if I show up to a client with anything other than a Nikon or Canon FF, they would show me the door. Fact is clients believe that gear makes the ‘man’. Not true, but I have lost clients in the early years with ‘non-pro’ looking gear. Even after they looked at the images of the ‘lesser’ cameras AND agreed that they loved them. Perception is what they are buying sometimes. For me it is worth the $$$ in cost difference to overcome this stupid hurdle. I know that it is the twelve inches behind the viewfinder as it has and does pay my bills. My 2 cents. YMMV.

    • True. For a pro, more considerations come into play than for an amateur. I would also stick with Canon or Nikon DSLRs if I had clients expecting just that.

  7. Glider, your comment about DOF is totally wrong… With micro 4/3, you multiply the aperture x2 to get FF equivalent… so your f2.8 becomes an equivalent of f5.6 on a full frame. When you say you get more light with MFT, wrong again… You should check before saying things that are incorrect. And the DOF is exactly the same for the same focal leight too. 12mm f2.8 on MFT is exactly the same DOF, Luminosity, and angle of view (at the same distance) as 24mm f5.6 on a Full Frame camera.

  8. and that is why you find that MFT lenses are sharp at F2.8… it is normal it’s a f5.6 equivalent, try to find a canon or nikon lens not sharp at f5.6…

    • It’s not really a 5.6 equiv since the actual exposure time is the same as if it was an f2.8 FF lens. The DoF is equiv to an FF at 5.6 though.

  9. I have a 5D3 (and a 5D2, and had a 5D), just bought the GH4 for video. Just bought the E-M1. Love my 5D3 but am not loving the weight and the stress of trying to pack enough lenses to effectively cover something like a renaissance faire for a weekend. Bought the GH4 specifically for video on aerial drone/uav as we get a lot of requests for 4K. Bought the E-M1 in large part for the ergonomics, as I can’t hold the GH4 comfortably – always feel like I’m going to drop it. I have small hands, but am used to gripped and ungripped 5D bodies. Reading this I realized the in-body stabilization is going to make it my carry-around camera under most circumstances.

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