GH4 gh5 sensor size speculation

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walkaboutcamera

Active member
1) the jvc ls300 sensor size is 23.46 x 15.64 mm, 3:2 aspect ratio. this tells us it is possible to put a sensor at least this large behind a m4/3 mount.

2) panasonic has told us we will get a 6k video photo mode from 18 mpix.

the above is what we know

3) for 6k i am going to guess at uhd x 1.5 as being the sensor pixel width giving 3840x1.5=5760.

4) making the assumption that one of the 4k modes of the gh5 will have the same crop size and 1:1 sampling as the gh4 for backward compatability, gh5 needs to have the same pixel density as the gh4. assuming of course.

5) this gives us a physical sensor width of 17.3x5760/4608=21.625mm. doable as jvc has proven.

6) back to pixel width, 5760x9/16=3240, and 5760x3240 as the 6k video photo mode.

7) 5760x3240=18,622,400 pixels.

8) lets assume a stills aspect ratio of 3:2, giving us 5760x2/3=3840 sensor pixel height, and 5760x3840=22,118,400 mpix. if you want a 4:3 aspect ratio do the math.



So we have 22 mega pixel sensor, 21.625mm x 14.42mm. I think, if it turns out to be the case, this would be a good move for Panasonic to stay competitive with Sony. The heart of my assumptions is point 4 above.
 
Hate to be a wet blanket, but this type of discussion is exactly what needs a wet blanket thrown on it, before the whole internet flames up in anticipation and expectation of something that just isn't going to happen... There is, IMO, zero chance (and by zero, I mean zero) that the GH5 will offer anything other than a 4/3 sensor. The entire GH line is 4/3, always has been, and almost certainly always will be.

Without a doubt, I feel certain that the GH5's 4K mode will be made from supersampling and downconverting its 6K sensor. The DVX00 does it that way, sampling a 5K sensor and downconverting to 4K, and the result is stellar-ly sharp 4K images. The GX8 has a 20mpix sensor, the GX85 has a 16mpix sensor, and both of those are 4/3 sized. There is no requirement for 1 sensor pixel to match up to 1 frame pixel, and in fact it can be argued that on a single-chip camera you definitely get lower quality doing it that way than you would get if you super-sampled and downconverted.

Furthermore, if the GH5 used a larger sensor than prior cameras, that would have been the first thing they trumpeted, not the last. And it would make all their existing Lumix lenses incompatible.

I would bet heavily that the GH5 will have a 4/3 sized sensor. I am prepared to be shocked into utter mutedness if it has an S35 sensor, but I consider it an extraordinarily low possibility.
 
The best I would hope for would be a multi aspect ratio sensor like the GH2 (and GH1?) had. I think that is a theoretically possible thing to hope for, but I would not expect it. For one thing, I don't know if there is even a modern sensor of a size that would allow this.
 
i really don't see a reason for them to change the sensor size, m43 is a market segment, cropped is another, full frame another, etc... it's great to have options, and i like m43 how it is. if you ditch it for cropped, that's another set of plusses and minuses.
 
Panasonic will ditch MFT in the AF-100 "replacement" when it comes out with a sub-$10,000 version of Varicam LT.

Overall, there's a strong movement toward larger and larger sensors. Fuji had been asked about a medium format camera for at least a couple of years. Their replies were non-committal at best ... until they announced a medium format camera to the world. Panasonic has own s35 pro cameras and a partnership with the full frame Leica line. At some point down the line, there will be a Panasonic full frame hybrid with a Leica lens lineup because there simply won't be much money left in the MFT niche.

But that is not the state of affairs at the moment. Olympus is looking at a $1,500-$1700 EM-1 MKII and GH5 will probably be a couple of hundred more (depending on the shipping date) and that means there's plenty of life left for MFT.
 
i also posted on personal view, this responce by davetv pretty much crushes my speculation.

If the sensor size is 21.625mm x 14.42mm, that would give a diagonal (image circle) of 26mm. Micro 4/3 lenses are designed for a diagonal of 21.63mm which means that you wouldn't be able to take full sensor 3:2 stills with native Micro 4/3 lenses.
A 16:9 crop of that sensor would give an effective sensor size of 21.625mm x 12.16mm. This gives a 24.8mm diagonal, again too large for Micro 4/3 lenses to have full coverage. So the 6K mode would only be usable with some kind of adapted APS-C or larger lenses.
It's hard to imagine Panasonic, which is one of the main companies that makes and sells Micro 4/3 lenses, releasing a Micro 4/3 mount camera where one of the main features/selling points does not work with the native lenses they sell.
For JVC (or others like Blackmagic, etc.) to release cameras intended for use with adapted 3rd party lenses makes sense, because they are just selling cameras. So it doesn't matter as much what lenses you use with it, as long as you buy their camera.
But Panasonic is also trying to sell people a lot of lenses. Especially because if you buy a lot of their lenses, not only does Panasonic make more money, but it also means that you are heavily invested in their system, are more likely to stay within that system, and more likely to buy more camera bodies and lenses within that system in the future.
 
Who cares? I don't mean to be rude but really I don't see the point of obsessing over this. If you want a larger sensor camera and obsess over a larger sensor camera then go use a larger sensor camera. Please leave my beloved m43 format the heck alone. I love m43 and don't want it to change. If I did I would go out and buy a super35mm camera. Really we already have that once you add a SpeedBooster for a heck of a lot less money then buying a new larger sensor camera. A lot of people assume a Speed Booster makes the lenses brighter which yes it does but in imaging a lot of things can be looked at in multiple ways. Instead of looking at the SB as affecting the lens I look at it as affecting the sensor. Really the same thing just in reverse. The SB basically turns the GH4 into a s35mm camera. Same DOF, same one stop advantage, same FOV calculations if one obsesses over that as well and you can think of the lenses as if they were on a s35mm sensor. For example Spielberg's beloved 28mm on s35mm is 28mm on the GH4 with the SB. If you slap on an inexpensive SB you really are using a s35mm sized GH4. wish granted. Yes you have to use non m43 lenses but the same is true if the GH5 had this larger sensor as well. You cannot cram a lens made for a small sensor onto a larger sensor and have it cover the sensor.

Besides this whole sensor size thing is such a massive load of BS. Take APS-C sensors for example. Sure they are larger but they also pack in more pixels. Think 24MP vs 16MP. Larger sensor but more pixels equals a photosite (pixel) size almost the same as a 16MP m43 sensor. Making a sensor larger but keeping the pixels the same size doesn't magically suck in more light. It just means you have more pixels which frankly are kind of a waste for 4k video. Yes there is the over sampling theory but that has a marginal affect at best on detail and does nothing for low light. In fact it makes it worse. Cinema cameras have a key advantage when it comes to their s35mm sensors, they only pack in enough pixels to shoot HD or 4k video. This means the pixels are larger. If you pack more pixels into a larger sensor GH5 you basically just have more of the same with the now added slight over sampling.

The only way a larger sensor would make sense on the GH5 for low light is if it still only had 16MP or better yet 12MP like the Sony A7S. That would make each pixel a massive light sucking bucket. The GH5 will not and cannot do this like Barry said because it would have zero m43 lenses it could use which would just be a really dumb mistake. They could be used in crop mode but why bother? Yes film makers might go gaga over it but photographers would absolutely hate it. This is still a DSLR and not a cinema camera. Again if you want cine there are plenty of stellar options out there.

Please leave the m43 format alone. Many of us love m43 and do not want to see it change. m43 is a solid and valid format and should not be messed with. If sales reduce enough then Panasonic should start a new mirrorless line all together to run in parallel but butchering a sort of Frankenstein monster hybrid freak of nature is not the way to go.
 
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