There has been a lot of speculation, interest, and confusion when it comes to the sensor in the new Panasonic GH3. Is it multi-aspect? Did Panasonic make it? Let's start with the first question: Does the GH3 have a multi-aspect ratio sensor? Photographer and Mu-43 member Giulio Scorio had the following to say on his excellent blog Small Camera Big Picture: My own sources at Panasonic say that the GH3 does not have a multi-aspect sensor, disabled or otherwise. This comes from pretty reliable although not infallible sources. It seems there are very few people in this world who know every detail about such matters! Most others are confirming this - no multi-aspect sensor. Second question: Who makes the GH3 sensor? A secondary question to this one is "Why do we care who makes the sensor?". That's what the Olympus marketing folks asked me when I pressed them on who made the E-M5 sensor, and there are a few reasons why we care: 1) At the present time, Sony is making the best sensors. 2) If it's Sony, that means both Panasonic and Olympus are using Sony for the sensors in their flagship cameras. 3) We're curious about this stuff. Back to the question: Did Panasonic make this sensor? Sony?? The first clue to this question is that by most accounts, it's not a multi-aspect sensor. If Panasonic were making this sensor, it seems likely that they would make it multi-aspect like the GH1 and GH2, so non-multi-aspect suggests the possibility that the sensor was made by someone else. The second clue is this juicy tidbit dropped by the well known Panasonic hacker Vitaliy Kiselev on his blog Personal-View.com: No beating around the bush there, and I'm guessing Vitaliy has some good sources. Third clue was given in a recent interview by EOSHD of Yoshiyuki Inoue, Senior Engineering Planner for the Panasonic GH3: That's a pretty heavy "no comment!" Surely if it were made by Panasonic, he would have said so. For what it's worth - probably not much in this case - my own sources at Panasonic said that they were not aware of any information to suggest that anyone other than Panasonic made the GH3 sensor. What do the specifications tell us? Panasonic GH3 (source): Total Pixels 17.20 Megapixels Camera Effective Pixels 16.05 Megapixels Panasonic G5 (source): Total Pixels 18.31 Megapixels Camera Effective Pixels 16.05 Megapixels Panasonic GH2 (source): Total Pixels 18.31 Megapixels Camera Effective Pixels 16.05 Megapixels Olympus OM-D E-M5 (source): Total pixels: 16.9 Megapixels Camera effective pixels: 16.1 Megapixels We already know that the GH2 and G5 use the same sensor. The question is whether the GH3 and E-M5 also use the same sensor. If the above specs are correct, then they do not. However, it's not hard to imagine some minor tweak or alternative interpretation that could lead to a small difference in pixel counts on what boils down to the same sensor. Taking all of the above into account, I'm 90% confident that the GH3 uses a Sony sensor, and if I had to guess, I'd say it is a slightly revised version of the E-M5 sensor. So what if it's a Sony sensor? We're having that discussion right here, so come weigh in!