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DxOmark Finally Tests the Olympus OM-D E-M5

Discussion in 'Micro 4/3 News and Rumors' started by Amin Sabet, Sep 24, 2012.

  1. Amin Sabet

    Amin Sabet Administrator

    Apr 10, 2009
    Boston, MA (USA)
    In perhaps the most anticipated and overdue sensor test of all time, DxOmark has finally tested the Olympus OM-D E-M5 sensor. We may never know why it took this long, but I'm thankful they decided to publish it after all this time.

    Link: DxOMark - Olympus OM-D E-M5: The best of the micro 4:3 cameras

    Those of us who have been using the OM-D E-M5 for a while won't be surprised by the DxOmark test results. Keep in mind that DxOmark reports have some limitations. Most importantly, they don't give you a sense of how the numbers and charts translate into real life results. For example, they tell you that the E-M5 has 1.7EV more dynamic range than a Panasonic G3 or GX1 (at base ISO), but you need additional experience or examples to show you how a 1.7EV difference affects pictures.

    Another thing I'd like to clarify is that when DxOmark talks about "manufacturer ISO" (aka nominal ISO) vs "measured ISO", people often think DxOmark's measured ISO is the "real" ISO while any deviation from this by the manufacturer is "overrating" (manufacturer ISO > measured) or "underrated" (manufacturer ISO < measured). Sometimes people go as far as to accuse manufacturers of "cheating", ie purposely misrating their ISO values to do better in tests. All of this is misunderstanding.

    To simplify things, manufacturers all specify an ISO based on the brightness that a JPEG will display for a given exposure (determined by shutter speed, aperture, and lighting conditions). RAW processors like Adobe Lightroom will automatically apply a similar tone curve to the in-camera processor in order to get the default conversion to the same overall brightness level as the in-camera JPEG. So for a given lighting condition, a Panasonic picture at f/2.8, 1/100s, ISO 400 will look as bright as an Olympus picture taken at f/2.8, 1/100s, ISO 400.

    Olympus tends to want more highlight headroom in the files at the expense of shadow latitude, so what they call ISO 400 usually corresponds to a lower level of analog gain (sensitivity) than what Panasonic calls ISO 400. This is why DxOmark says that Olympus ISO 400 is measured ISO 214. In order to give you the same final brightness, the Olympus file gets "pushed" by the in-camera tone curve (or Lightroom, etc) more than the Panasonic file gets "pushed" by its tone curve. In other words, an Olympus camera will choose a faster shutter speed in order to preserve the highlights, push the file enough to get the same overall brightness (as a Panasonic file with a longer exposure), and as a result the Olympus RAW file will have noisier shadows and more more highlight detail than a Panasonic using the same sensor.

    Depending on the testing methods used, this may result in the Olympus camera being disadvantaged during noise testing, exactly the opposite of what people usually say when they accuse Olympus of "cheating" by "overrating" their ISO. It may also result in a false advantage for highlight testing, and will certainly result in a false advantage for most DR measurements based on in-camera JPEG testing (most review outfits).

    DxOmark uses an arbitrary definition of ISO which relates the camera sensitivity to the amount of highlight headroom for that given sensitivity. It's a great way for them to standardize results when testing many different cameras from different manufacturers. However, DxOmark's definition of ISO (measured ISO) is non-standard and actually technically less correct than the definition which the manufacturers use (which corresponds to one of the standard definitions of ISO.

    So what can we take away from the DxOmark results?

    First, Micro 4/3 as a system has closed the dynamic range gap with APS-C cameras. The latest Sony NEX cameras maintain a slim margin advantage in this aspect (less than half a stop for the NEX-5N), while the E-M5 (and by extension the E-PL5, E-PM2, and probably GH3) sensor's DR now exceeds that of any previously measured APS-C sensor from a Canon or Samsung camera.

    Second, the Micro 4/3 system is now punching above its weight in terms of low light high ISO performance. The E-M5 sensor tested only 0.3 stops worse than the NEX cameras in this category, whereas one would expect a 0.7 stop disadvantage based on format size. In other words, it would take a stabilized 33mm f/1.6 lens on a Sony NEX body to match the low light capability of the Panasonic Leica 25mm f/1.4 lens on a current Olympus body, or a stabilized f/3.2 zoom to match the low light capability of the Panasonic 12-35mm zoom on the GH3 (assuming that camera uses the same sensor).

    These are small differences. The bottom line is that the E-M5 sensor is a step forward for the system. Whether these sensor advances help us make substantially better photos is an entirely separate discussion. I'd argue that for most people under most circumstances, the answer is no.
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  2. jloden

    jloden Mu-43 Hall of Famer

    May 15, 2012
    Hunterdon County, NJ
    Glad to see the test results, even if just to give an approximate placing for the OM-D EM-5 up against APS-C sensors since it helps people understand about where our format sits in the scheme of things.

    Things I'm interested in most going forward (I'm assuming the GH3 tests about the same):

    1) What the next crop of APS-C sensor results looks like. Sony and Nikon have taken some pretty big jumps into MF territory when it comes to dynamic range on the latest FF sensors. I'm curious to see how that trickles down to the APS-C lines.

    2) What the Fuji X-Pro1 / X-E1 sensor results look like. The X100 rating is about even with the OM-D results, but I'd be very interested to see where the X-Pro1 sensor rates comparatively.
  3. Djarum

    Djarum Super Moderator Subscribing Member

    Dec 15, 2009
    Huntsville, AL, USA
    I can't wait until the E-PL5 comes out. With this sensor, I think Olympus will have an excllent entry and mid-level products with really good IQ.
  4. krugorg

    krugorg Mu-43 Hall of Famer

    Jul 18, 2011
    Minnesota USA
    I am guessing this would be somewhere in the range of the NEX-5N to Pentax K-01, since it is the same sensor (apart from the Fuji color filter implementation, etc.)?
  5. RT_Panther

    RT_Panther Mu-43 Legend

    May 4, 2011
    Hopefully now, there won't as much negativity towards Sony as there used to be & instead, Olympus users can enjoy the same symbiotic relationship that Sony/Pentax/Nikon users enjoy :smile: (since the OMD has a Sony fab'd sensor)
  6. Jonathan F/2

    Jonathan F/2 Mu-43 Hall of Famer

    Aug 10, 2011
    Los Angeles, USA
    I'm not sure I like Sony being the only game in town. I'm surprised Canon hasn't leveraged their sensor development to other manufacturers. Who knows, maybe Panasonic's FF aspirations may involve Canon in order to combat Sony's stills and video dominance! :wink:
  7. RT_Panther

    RT_Panther Mu-43 Legend

    May 4, 2011
    Perhaps Canon didn't want to - in much the same way that Panasonic gave Olympus the shaft (IMHO)......

    Panasonic left Olympus little choice.....
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  8. RT_Panther

    RT_Panther Mu-43 Legend

    May 4, 2011
    And it wouldn't surprise me at all if part of the reason why Fuji went APS-C instead of Micro Four Thirds is because Panasonic gave Fuji the shaft too in the sensor department....
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  9. phl0wtography

    phl0wtography Mu-43 Veteran

    Apr 15, 2011
    Unfortunately they haven't tested any of the nice mFT primes (12,14,17,20,25,45) on the OM-D's sensor. Now THAT's what I'd be interested in, how those lenses perform on the 16mp Sony sensor.
  10. krugorg

    krugorg Mu-43 Hall of Famer

    Jul 18, 2011
    Minnesota USA
    +1 ... good to have some competition with sensors, just like with the camera systems. Hope Panasonic continues pushing, Canon steps it up, and we see new stuff from the smaller guys (Aptina, CMOSIS).

    Aptina new 1" sensor with 1080p/120fps
  11. RT_Panther

    RT_Panther Mu-43 Legend

    May 4, 2011
    I still say that if you don't have a requirement to shoot in pitch black conditions, then Foveon rules!!!!! :biggrin:
  12. meyerweb

    meyerweb Mu-43 Hall of Famer Subscribing Member

    Sep 5, 2011
    I'm not sure anyone who had other options would choose a Canon sensor now. They seem to have fallen rather badly behind Sony.
  13. Art

    Art Mu-43 All-Pro

    Mar 13, 2011
    San Francisco, CA
    OM-D almost matches DR of my RX100 (12.3 vs 12.4) but even better in high ISO. Is high ISO measured at a pixel level? How about measuring noise when resized for normal viewing size?
  14. digitalandfilm

    digitalandfilm Mu-43 All-Pro

    Jul 18, 2011
    If you are a sunny day shooter and limit yourself to iso400- then the Fovean does perform well. Unfortunately, I seem to have a hard time constraining myself to iso400.
  15. Amin Sabet

    Amin Sabet Administrator

    Apr 10, 2009
    Boston, MA (USA)
    12.3 and 12.4 are the same, within the error of their testing. The E-P1, E-P2, and E-P3 all use exactly the same sensor and had a tested DR of 10.3, 10.4, and 10.1 respectively by DxOmark. The same is true for other cameras which share the same sensor. Their DR results should probably say +/- 0.3 EV.

    They do it both ways. When you look at their curves, you can choose either "screen" (per pixel) or print (normalized to viewing size). It defaults to print.
  16. NJH

    NJH Mu-43 Regular

    Mar 8, 2012
    South West England
    The really interesting thing is that there are really no surprises IMHO. One could easily have made an educated guess about the score and come up with those numbers. I know I did, the sensor in my X100 is the same Sony 12 Mp sensor used in the 12 Mp Nikons and scores the same dxomark score as those cameras. Everyone reckons the jump from the 12Mp to the 16 Mp Sony sensor was worth about 1/2 to 2/3ev or about 7 dxomarks. Now if someone took a score of about 80 for a 16Mp Sony sensor and just degraded it by the size difference between APS-C and 4/3 you get surprise surprise a score in the low 70's. Its a tiny bit worse than the Sony A57 SLT with a 16 Mp sensor which loose 1/2 ev in the translucent mirror and a bit worse high ISO than the X100 which tallies with the images I have seen posted from both cameras.

    It's still pretty remarkable though and the one good thing about dxomark finally publishing test results is it will shut up the idiots who regardless of the millions of images shot with the camera claim it as some sort of unworthy fad/myth.
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  17. RT_Panther

    RT_Panther Mu-43 Legend

    May 4, 2011
    Strobists in studios too....:wink:
  18. Laurentiu Cristofor

    Laurentiu Cristofor Mu-43 Veteran

    Mar 9, 2012
    Nice score and a good example of the benefit of using Sony sensor technology.

    I would expect the XP-1 to score better than the K-01 given the low light samples I have seen online. I am really curious about this result.
  19. With_Eyes_Unclouded

    With_Eyes_Unclouded Mu-43 All-Pro

    Apr 17, 2012
    Nothing really surprising for anyone using the camera and not bothered by what others want to believe. But I guess it's kind of important in making it "official". :biggrin:

    Since the real important thing is the actual, real world camera/system performance, let's not forget what Amin desribes in the OP. The important point, IMO, is that, today, a OM-D with in-body IS and current selection of fast lenses offers better performace overall than APS-C cameras on the market. And I mean, having (practically) the same DR performance as the best of them and being able to use one to two stops lower ISO than any of them at a given situation, due to a better performing IS. Once again it becomes evident it's the system overall, not a specific camera or sensor format.
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  20. LovinTheEP2

    LovinTheEP2 Mu-43 Top Veteran

    Feb 15, 2011
    Amin, same sensor but tweaked setup with different AA filters etc. Would that not effect the DR rating? Guess that would be an error if the testing is only completed a single camera and not an average of 2 or more units.

    Still.. either way. Good to see how much better the 4/3 new OM-D/Next gen pens sensor is and how far ahead the system lies when compared to the 1" Nikon - miles ahead.
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