Jump to content
Andrew Reid

Time to step up - Panasonic GH5 must go 6K Super 35mm to compete in 2016

Recommended Posts

53 minutes ago, Nathan Gabriel said:

I'm just wondering about your chart because I don't understand these things at all. Is the diffraction inherent in the optics out is it possible some new sensor technology can give better results?

Diffraction is an inherent property of light passing through an aperture. What you end up with is each part of the light turns into an Airy Disc with particular physical properties. The diameter of the disc only depends on the f-stop, nothing else. Hence the smaller the pixels the more of an issue it is. This is worth a read and includes a calculator (just ignore the camera section in the lower half):
http://www.cambridgeincolour.com/tutorials/diffraction-photography.htm
(Astronomers are even more interested, as stars, being point light sources, really show the effect.)

Generally (IMHO) diffraction blurring starts to become an issue at the pixel level when it hits two pixel widths and gets worse at three widths. Exactly how bad it is depends on stuff like the strength of the anti-aliasing filter (if any) and how much blurring the de-bayering algorithm adds (which is always some). It isn't a hard limit, it's always there and just gets worse, so people have to define the point they start to care about it, which varies somewhat depending on who you read. For still photography it has been taken, for a fair while now, that a 30um blur on a FF sensor (divide by crop factor for others) is the limit for good sharpness of uncropped still images (which comes from lots of perceptual testing of people and a bunch of assumptions, like using 8"x10" images at a particular viewing distance). At the pixel level the 2-3 pixel widths seems to be where people are. I personally think if you are at 2 pixels or less you can ignore diffraction effects at the pixel level (compared to other factors).

(Edit) P.S. reverse engineering the graph on the previous page gives about 4.4um as the diffraction limit for f8 (10.7um Airy disc), which is 2.43 pixels and 5.8um for f11 (14.7um Airy disc), which is 2.53 pixels, so I suspect they used 2.5 pixels as their limit. It doesn't magically get really bad at this point, just gradually worse.

P.P.S. Also remember as you move away from the plane of focus the image gets gradually blurrier, this is where the 30um value is most often used, as the limits of the depth of field. Diffraction softening just adds to this.

 

Share this post


Link to post
Share on other sites
EOSHD Pro Color for Sony cameras EOSHD Pro LOG for Sony CamerasEOSHD C-LOG and Film Profiles for All Canon DSLRs

My dream for the GH5

200 mbps with a better compression algorithim 4K & 1080p IPB

RAW 1080p like blackmagic pocket

I can live with the sensor size just need way better noise performance. If the image can stay clean up to 3200 that would be admirable.

12 megapixel sensor for full pixel readout of 4k and oversamples 1080 60fps

Share this post


Link to post
Share on other sites

I think if they can get a scaled-up version of Sony's sensors for the RX10ii & iii or a scaled up Sony IMX260 (including the phase-detect AF) for the GH5, then the camera could be extremely good and also possess a high (at least stills) resolution and good slow motion options. Or perhaps Sony or Samsung has new sensors that will work well for this.

Share this post


Link to post
Share on other sites
1 hour ago, vaga said:

I think if they can get a scaled-up version of Sony's sensors for the RX10ii & iii or a scaled up Sony IMX260 (including the phase-detect AF) for the GH5, then the camera could be extremely good and also possess a high (at least stills) resolution and good slow motion options. Or perhaps Sony or Samsung has new sensors that will work well for this.

If 1Inch sensors can pull off 20 Megapixels that look respectable, then 4/3rd sensors should be able to pull off about 27 Megapixels that look respectable (2.7x crop vs 2.0 crop).

The only other way to do this would be to reverse engineer (not sure if it is the right term over here) the Metabones Speed booster patent, and use a glass in between the M4/3 mount and an APS-C sensor in a M4/3rd body.

I also noticed that almost Everyone is Confused as to what they want from the next GH Camera, keeping in mind the position it fits into (it's not a Canon DSLR, and it doesn't want to trespass into the BlackMagic territory wrt to the codec). I guess a centre-point would be a 4-2-2, which the GH4 already does, though externally. So now it must do it internally. I am guessing that it will be a new 24MP sensor (someone mentioned that as the maximum resolution possible for M4/3rds). If they can nail post focus at 5k or 6k, along with the 5k or 6k photo mode, it would be superb.

The GH4 already has superb battery life. Only the GX85's 5-axis stabilisation may be the extra features. Also, I felt (from Matt's talk, or someone else's) that Panasonic will re-introduce the YAGH module, but streamlined this time, and not look so outrightly cumbersome and functionless. The SDIs and time codes seemed inappropriate. Maybe micro XLR, and modules for SSDs.

I also wonder if a better and higher bitrate (200-300 mbps) 5k codec would help. 

Share this post


Link to post
Share on other sites
58 minutes ago, sanveer said:

The GH4 already has superb battery life. Only the GX85's 5-axis stabilisation may be the extra features. Also, I felt (from Matt's talk, or someone else's) that Panasonic will re-introduce the YAGH module, but streamlined this time, and not look so outrightly cumbersome and functionless. The SDIs and time codes seemed inappropriate. Maybe micro XLR, and modules for SSDs.

I just want the 5-axis, better low light, a recording YAGH for backup and the same focus transitioning as the 80d without the stuttering and self doubt. I know, not easy, but not incredibly out of reach either.

The YAGH was a missed opportunity to replace the AF100 but the idea was really clever, I hope you're right and sell a new version.

Share this post


Link to post
Share on other sites

It's disappointing that he has taken the oversized sensor off the table completely, but if they can eliminate the few compromises/shortcomings of the GH4, along with even a modest spec increase, and emphasize the usability and reliability of the camera they could still have a market share. Not everyone can/wants to deal with mega-jello or overheating or fleeting battery life.

Basically, just give us a GH4 with clean 1080/120, and 4K with no crop at >30p (even if it's only 36 or 48p). Improve low-light as much as possible, go down to 12MP if necessary, nobody complains about the a7S being 12MP. Get rolling shutter as low as you can- sub-20ms for 4K, 10-12ms or better for 1080p. You're not gonna make the GH4 big or pricey enough for CFast/XQD/SSD/etc, and UHS-II is still kinda pricey, so go to h265 so you can still use U3 SD. Or go to UHS-II and stick with h264. Either way you need to do 10-bit 4:2:2 internal, at 100-150 mbps for h265, or 200-250mbps or more for h264.

Share this post


Link to post
Share on other sites

Panasonic won't introduce a S35 sensor. Their entire camera line-up is designed around the m4/3 sensor size, with a large number of complimentary lenses. For them to go down the S35/APS-C path would require a lot of development on the lens side, and would result in the strange situation that Sony found itself in with its full frame E-mount offerings - barely any lenses to go with it, forcing them to implement an APS-C crop mode, and adapters for their 'other' lens mount system to work on the camera. I highly doubt Panasonic's going down that path - even the AF100 had an m4/3 sensor.

I would also be surprised if they went 10-bit internal. I think Panasonic would be a lot smarter about it, and look more to an AF100 successor, which would/could have 10-bit internal, perhaps recording onto P2 cards, for easy slide-in to the Varicam line-up. 10-bit out via HDMI (or SDI with a new YAGH interface) might be something they'd look into. I would imagine the GH5 will be much better low-light wise than the GH4. I also doubt it will he H.265 if the camera comes out this year. 

Share this post


Link to post
Share on other sites

I know many are huge fans but the GH line never made me happy. Even those crazy high bitrate hacks on thew GH2 and the GH4 even with log. I just felt there was something baked-in about the shadows that limited how you could manipulate it in post, so after demoing loads of footage I gave then a miss.

I've seen decent stuff made with them though, especially using speed boosters, so I'm interested to see what happens with the next model. I hope they don't do a Canon and stangnate specs. I don't think they can really afford to...

Share this post


Link to post
Share on other sites

I would echo the sentiment of many others here. More resolution is of little value at this point. 6K, 60K, who cares when the video color is mediocre (4:2:0). What professionals and prosumers want is better color and dynamic range. RAW video or at the very least true 4:2:2 bit footage (no wrapper BS) I hope Panasonic is listening to feedback with their next camera.

Share this post


Link to post
Share on other sites

I'm ok with just 4K, but with higher fps.

 

Or better yet they should do the following;

2.5K Raw cinema-dng up to 100fps; internal

1080P-120fps @10-bit 422 internal 

Along with the other features I listed in my post above.

Share this post


Link to post
Share on other sites

I'd be totally happy with less megapixels if we get full-sensor 4K, better color integrity, and another half to full stop of DR. Everything else just comes down to cramming in all the features from their previous cameras and doing a hair of catch-up with their competitors on framerates and (to a lesser extent) color science.

Share this post


Link to post
Share on other sites

Would have wanted much better low light performance and not a lot else. Kept checking for release news amongst the many rumour mills for ten months but suspected around the time of purchasing the a7sii (February) that there would be nothing concrete before Photokina in the Autumn. Even then, it might never happen - or does happen but without improved low light.

It seems that one year in Sony time is two years in Panasonic time. Can't help thinking that the pressure is on Panasonic to come up with a worldy of a camera if they are going to grab back some ground from their competitors in the prosumer market.

Share this post


Link to post
Share on other sites

I know the GH5 will be excellent and full of new features. I still hope it will correct Panasonic "blind spot" and finally shows basic exposure information in video modes (iso, aperture and shutter speed). Is it too much to ask?

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


×
×
  • Create New...