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Confirmed: Panasonic G5 Uses the GH2 Sensor with Multi-Aspect Disabled

Discussion in 'Micro 4/3 News and Rumors' started by Amin Sabet, Aug 30, 2012.

  1. Amin Sabet

    Amin Sabet Administrator

    Apr 10, 2009
    Boston, MA (USA)
    I've received confirmation from sources at Panasonic that the Panasonic G5 uses the same sensor as the Panasonic GH2. Many have suspected this to be the case since the specifications for the G5 sensor indicate 18.3 MP total and 16.1MP effective, which is the same as the GH2.

    I actually received this information weeks ago but was reluctant to publish it as I had a hard time believing it to be true. The reason for the "oversized" 18MP sensor in the GH series is that those cameras have multi-aspect ratio sensors - ie, the 4:3, 3:2, and 16:9 output are cropped from an oversized sensor such that the diagonal angle of view is preserved in each case. In contrast, other Micro 4/3 cameras crop the 3:2 and 16:9 output from their 4:3 output such that the diagonal angle of view is reduced in 3:2 and 16:9.

    Looking at the file dimensions from the GH2 and G5, it's clear that the latter does not make use of a multi-aspect ratio sensor.

    • [4:3] 4,608 x 3,456
    • [3:2] 4,752 x 3,168
    • [16:9] 4,976 x 2,800

    • [4:3] 4,608 x 3,456
    • [3:2] 4,608 x 3,072
    • [16:9] 4,608 x 2,592

    I've now learned that while the G5 does in fact use the same sensor as the GH2, the multi-aspect ratio feature of the sensor could not be included without compromising other improvements to the still and imaging performance which were achieved in conjunction with the new Venus VII FHD engine:

    • Video now capable of 1,920 x 1,080, 60p (vs 30p with GH2)
    • Still photography burst rate now 6fps (vs 5fps with GH2)
    • AF speed improved on G5 compared with GH2

    It was implied that there were other improvements, including some directly affecting, image quality which were made possible by leaving out multi-aspect ratio capability. The bottom line is that Panasonic chose to leave out multi-aspect capability in order to include other image quality and performance improvements that they felt would be more important to customers.

    Like the Olympus E-M5, the GH2/G5 uses a "digital" sensor, meaning the analog-to-digital conversion (ADC) takes place on the sensor. In contrast, an "analog" sensor like the one in the G3/GX1 sends analog information to an offboard ADC. A digital sensor will generally have a faster readout and slightly lower read noise, the latter of which explains the slightly better dynamic range of the GH2 and G5 as compared to G3 and GX1.

    As many here are aware, Vitaliy Kiselev has developed and released tools which allow us to hack Panasonic cameras, notably the GH1 and GH2, to remove firmware restrictions. The primary purpose of hacking these cameras has been to allow changing of video encoding parameters. In particular, increasing the video recording bit rate can significantly improve video quality.

    After learning about the G5 sensor, my first thought was whether Vitaliy might be able to unlock its multi-aspect capability. Presumably this would involve a number of tradeoffs as specified above, but I've no doubt that some adventurous G5 users would welcome the choice.
    • Like Like x 12
  2. viztyger

    viztyger Mu-43 Regular

    Dec 16, 2009
    Very interesting, Amin. It makes me wonder what aspects of sensor performance would have been impacted by including the multi-aspect feature. I would also hope that the GH3 will feature a sensor that offers enhanced performance without sacrificing the multi-aspect feature. The ability to shoot at various aspect ratios while using the lens' full imaging circle was one of the reasons why I shot with both the GH1 and GH2.
  3. Amin Sabet

    Amin Sabet Administrator

    Apr 10, 2009
    Boston, MA (USA)
    The only specific compromises they mentioned were in the OP - AF performance, image quality (I assume talking in-camera JPEGs here), a modest bump in burst mode fps, and 60p vs 30p video. It's interesting to see how the camera CPU/GPU affect what is possible to get out of these sensors. I expect that the GH3 will offer a brand new multi-aspect sensor and the necessary processing muscle to get the most out of it. Panasonic doesn't seem to hold much back with the GH series (Vitaliy hacks notwithstanding).
  4. Steven

    Steven Mu-43 All-Pro

    May 25, 2012
    Interesting. I don't know much about sensor technology, but it just seems a bit odd to get too happy about a 2 year old sensor getting handed down to what is supposed to be a number 2 camera for the brand pretty much. Sony doesn't seem to do that, do they?
    Is there no room for improvement left aside from faster processing? Maybe they should just start buying sensors from Sony?
  5. jyc860923

    jyc860923 Mu-43 Hall of Famer Subscribing Member

    Feb 28, 2012
    Shenyang, China
    the multi-aspects is the most interesting feature that I can think of has been disabled, however this could avoid expanding on the width that causes IQ loss, I use to have panasonic P&S and I remember the IQ loss on the extreme border was quite obvious. Can I see any sample indicating how well GH2 handles this? (if we have the chance of hacking G5 to it)
  6. meyerweb

    meyerweb Mu-43 Hall of Famer Subscribing Member

    Sep 5, 2011
    I'm not a camera designer, but I don't see why any of those improvements preclude a higher resolution or multi-aspect sensor. It might have been more difficult or expensive, but I suspect the real reason the G5 doesn't have the multi-aspect sensor has more to do with marketing (i.e., differentiating the GH from the G) than it does technology.

    I think your issues with the P&S had more to do with lens quality than the format. The GH2 is fine at the edges with good lenses. I suppose that lenses that are already weak at the edges might fair slightly worse in wide format mode, but I have no issues with even 16:9 mode with any of my current lenses, which include:

    • Like Like x 2
  7. I don't get the relationship between the the abilityt record different aspect ratios and the AF, fps either. however, it is nice that Panasonic has seen fit to let the GH2 sensor technology trickle further down the line rather than hiding it away in the high-end model only.

    The IQ in the extreme corners should be the same regardless of the aspect ratio since all three fit in the same image circle. What you may be seeing is that in the wider aspect ratios there is very slightly more of the image placed closer to the edge of the circle so there can can be some more degradation visible over a larger number of pixels at each edge. The difference is marginal enough that it would be very hard to see, though.
    • Like Like x 2
  8. Jonathan F/2

    Jonathan F/2 Mu-43 Hall of Famer

    Aug 10, 2011
    Los Angeles, USA
    +1 on that. I don't see why they could include this feature.
  9. With_Eyes_Unclouded

    With_Eyes_Unclouded Mu-43 All-Pro

    Apr 17, 2012

    Not to mention it's a crippled version of this sensor, regarding one of its most important tech aspects.

    I can't see how someone would be enthusiastic about that. It's a good sensor anyway (and with some tweeks in the G5, if I understand correctly, plus new imaging engine), but I'm waiting to see what the new sensor in the GH3 is all about. Speaking of sensor performance only, if the GH3 doesn't at least match the one in the OM-D, I'd say that Panasonic is loosing this battle to Sony.
  10. arad85

    arad85 Mu-43 Veteran

    Aug 16, 2012
    Because it is better compared to the current gen at lower ISOs, is packaged in an ergonomically designed small body with great handling and sells for not many pennies (I got mine for £420 in the UK Panasonic offer).

    It's not the greatest sensor, but then it is priced accordingly.
  11. Sometimes a 2 year old (or even 3 year old) sensor is more exciting than a 1 year old sensor

    DxOMark - Compare cameras side by side

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  12. jnewell

    jnewell Mu-43 All-Pro

    Jun 23, 2011
    Boston, MA
    Ahead in DR, but behind in high ISO?
  13. With_Eyes_Unclouded

    With_Eyes_Unclouded Mu-43 All-Pro

    Apr 17, 2012
    My point is they used an older, proven sensor in a new body, with some current tech included, minus the "unique" features of the original implementation.

    That's fine and, to be fair, rational. Nothing to write home about though. Which isn't to say -by any means- that the G5 isn't an awesome value as things are today.
  14. Robstar1963

    Robstar1963 Mu-43 All-Pro Subscribing Member

    Jun 10, 2011
    Isle of Wight England UK
    Robert (Rob)
    That's the crux of the matter. Panasonic recycling but improving the 'Old' GH2 sensor means that we can have a new camera with performance not far away from the E-M5 (and as such not far from the 'state of the art') at about half the cost
    That has to to be a very fair trade off and one that I am more than happy to compromise with

    Olympus has been using 'hand me own' sensors for some time and were still at 12mp for their last range as a result. At least Panasonic moved on with their previous range in terms of an upping of the resolution

    I agree that the real reason that the multi aspect is not included is because people who see that as a major benefit would economise and buy the G5 rather than spending more on the flagship model which includes this feature
    I really do not believe the rationale given - but that's business at the end of the day
    This situation is no different whatsoever from the situation you find yourself in at the car showroom where a particular feature is strictly reserved for and only available on a top of the range model which you have to pay an extra few grand on - making a higher profit margin for the car company as a result - you pays your money and takes your choice' as they say
    It's called marketing and maximising your opportunities to increase revenue etc etc

    Id just rather Panasonic were a little more 'honest' and said "we've included some features only on the top of the range model" to preserve its exclusivity and to enable us to keep the price of the lower model more affordable / reasonable.

    An additional point to bear in mind is that by this marketing strategy Panasonic upholds the sales of current GH2s to some degree and (also perhaps only to some degree) prevents the used values of GH2s falling too abruptly as this is currently the only multi aspect capable model available which owners who spent over £1000.00 may appreciate - again all part of what must be a very well thought out/discussed and more complicated strategy than that which first meets the eye of us the buyers who simply 'want our cake and eat it' and get everything for next to nothing !

    Anyway Im very happy with my G5 especially at the offer price and will be drooling over the GH3 which I won't be able to afford or justify untill near the end of its product cycle - c'est la vie
  15. Pelao

    Pelao Mu-43 Top Veteran

    Feb 3, 2010
    Ontario, Canada
    Interesting information for the Geek in me.

    I wonder will this information now be reflected in comments on the G5s image quality. Will people start to see things differently? Or will the camera be judged on its merits, regardless of the sensor?
  16. Amin Sabet

    Amin Sabet Administrator

    Apr 10, 2009
    Boston, MA (USA)
    If so they'll be in good company because everyone is losing that battle to Sony right now. These things go in cycles though. Canon was king of the hill for several years, and now their sensor tech is right there with Panasonic. If Panasonic continues to invest resources in sensor development, I'm confident they will remain competitive. I'd not like to see Sony become the sole supplier of sensors for our system.

    Sent from my Galaxy Nexus using Mu-43 App
  17. With_Eyes_Unclouded

    With_Eyes_Unclouded Mu-43 All-Pro

    Apr 17, 2012
    I totally agree with this line of thought.

    In fact, I have to confess that, when the OM-D came out, and, from the first reports it was evident something seriously great was going on with its sensor, I was one of the people thinking it was a new Panasonic sensor. This was an exciting thought, since it meant resources within the :43: group were highly competitive.

    That said, I have to answer to Robstar1963 above:

    Rob, it became evident from statements (from Panasonic) during the last weeks, that they were not comfortable giving Olympus their latest sensors. It is not an Olympus problem. This is what they had to work with, until Sony came through and provided them with a first class sensor.

    The best scenario for me would be having both brilliant Sony sensors AND Panasonic or even other manufacturer sensors (e.g. would Samsung provide an oversized sensor with multi aspect capability?). I don't want a Sony monopoly either; it just seems they are doing things right, in the imaging tech department that is (because in designing a complete mirorless system, cameras AND lenses, they seriously suck).
  18. pictor

    pictor Mu-43 Top Veteran

    Jul 17, 2010
    I like using mainly three aspect ratios: 4:3, 3:2 and 1:1. On very rare occasions I use 5:4. Obviously, using 4:3, 1:1 and 5:4 does not make any difference regarding the choice of either the GH2 or the G5. Using 3:2 results in a difference of about 0.9 megapixels, which I don't care for.

    The G5 offers great value for the money and I consider buying it. Some people know, that I contemplated about buying the E-M5, but finally I withdrew because I did not like the ergonomics well enough as soon I was able to hold it in my hands: I use my left eye for looking through the viewfinder and operating the controls on the top turned out to be too fiddly. The G5 seems to be much better in that regard.
  19. gcogger

    gcogger Mu-43 Veteran Subscribing Member

    May 25, 2010
    I think most people like the multi-aspect GH2 because 3:2 and 16:9 give a wider field of view, not because of the extra megapixel count.
  20. pictor

    pictor Mu-43 Top Veteran

    Jul 17, 2010
    Yes, that's right, but the differences are very small regarding the wider field of view, too, at least for 3:2. The difference is slightly more significant for 16:9, though (but I virtually never use that anyway). The larger the difference regarding the fields of view, the bigger the difference regarding the megapixels will be.
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