Making sense of the Panasonic GH4

[Hannah Lisa Richmond]

I thought I would start a thread that focuses ONLY on the Panasonic GH4, and getting the most out of it - rather than start yet another thread debating if Camera X is better than Camera Y etc. Just the GH4 for this one.

 

I'm excited about what this camera can do and how it could affect my professional work.

 

There are just a few things I want to make sense about this camera, in one place, as other topics are full of conflicting information and debates of whether the camera is good or not. 

 

I do have an interest in 4k (as it makes better 1080p), so wanted to figure out how you would get the best out of it. I do pretty much everything from controlled shoots to run and gun. Medium to heavy grading always.

 

 

1. Not everyone wants the brick. I don't totally need it. It may look a bit awkward but I can see it being useful for studio setups/interviews etc. 10 bit 422 4k sounds lovely, but is it possible an external recorder capable of recording 4k footage could do this over the cameras HDMI port? 

 

2. For those who want the brick, how would you envisage setting this up on a rig? (seems like it could get messy if not done carefully.)

 

3. I need slow motion for my work. I get asked to do it all the time. Will 96fps conform only to 24fps? And would it be possible to record this onto an external at 10 bit? 

 

4. For internal 1080p and 4k.... memory card options? 

 

5. What are the best solutions out there to record 1080p 10 bit 422 on the GH4, and are there any options for 4k on the horizon? 

 

6. Does anybody know for sure the actual dynamic range? 

 

 

These are the questions I have for now. Please share your own :)

[Quirky]

I thought I would start a thread that focuses ONLY on the Panasonic GH4, and getting the most out of it - rather than start yet another thread debating if Camera X is better than Camera Y etc. Just the GH4 for this one.

 

I'm excited about what this camera can do and how it could affect my professional work.

 

There are just a few things I want to make sense about this camera, in one place, as other topics are full of conflicting information and debates of whether the camera is good or not. 

 

7. Full pixel readout vs. pixel binning, which way is it?

So the GH4 is cropping the mFT sensor when recording in 4K, but is the camera really doing a full pixel readout in that cropped area, or is it pixel binning it, after all? 

[Andrew Reid]

I thought I would start a thread that focuses ONLY on the Panasonic GH4, and getting the most out of it - rather than start yet another thread debating if Camera X is better than Camera Y etc. Just the GH4 for this one.

 

I'm excited about what this camera can do and how it could affect my professional work.

 

There are just a few things I want to make sense about this camera, in one place, as other topics are full of conflicting information and debates of whether the camera is good or not. 

 

I do have an interest in 4k (as it makes better 1080p), so wanted to figure out how you would get the best out of it. I do pretty much everything from controlled shoots to run and gun. Medium to heavy grading always.

 

 

1. Not everyone wants the brick. I don't totally need it. It may look a bit awkward but I can see it being useful for studio setups/interviews etc. 10 bit 422 4k sounds lovely, but is it possible an external recorder capable of recording 4k footage could do this over the cameras HDMI port? 

 

2. For those who want the brick, how would you envisage setting this up on a rig? (seems like it could get messy if not done carefully.)

 

3. I need slow motion for my work. I get asked to do it all the time. Will 96fps conform only to 24fps? And would it be possible to record this onto an external at 10 bit? 

 

4. For internal 1080p and 4k.... memory card options? 

 

5. What are the best solutions out there to record 1080p 10 bit 422 on the GH4, and are there any options for 4k on the horizon? 

 

6. Does anybody know for sure the actual dynamic range? 

 

 

These are the questions I have for now. Please share your own :)

 

1. Nobody seems to knows yet. I've asked a shooter in the US who shot with the GH4 yesterday to try and find out. 4K playback I have seen working and the HDMI is 4K capable. Live, clean, uncompressed, 8bit or 10bit, nobody knows. Early days yet.

 

2. The brick has to go under the camera. It's not that heavy but it's a shame it cannot be run off a lead to somewhere else on the rig of your choosing, but it's one less lead to snag and one less socket to risk. I am sure there will be cages designed to fit the YAGH brick + GH4 as one unit. But when? Who knows.

 

3. Slow-mo conforms to a 23.98p, 24p, 25p and 30p. Full slow-mo specs -

 

 

4. 95Mb/s Sandisk Extreme likely won't cut it for 4K or 1080p in ALL-I at 200Mbit but is fine for 1080p IPB. For 4K you need newer 280Mb/s SanDisk Pro card or new Panasonic ones. Source: 

First fun #GH4 challenge of the day: our @SanDisk 95mbs SDXC not likeing #4K. Using SDHC II 280mbs instead. pic.twitter.com/CmFPKVEVtz

— Eduardo Angel ★ (@EA_Photo)

February 8, 2014

 

5. Atomos Samurai. You need the higher res screen for focus in 4K. Ninja not as crisp. For 4K you will need Convergent Design Odyssey or similar.

 

6. Nobody has done a controlled chart test yet for DR but expect it to be similar to a GX7 JPEG. Just shy of 12 stops baked into the image.

[HJD]

1. I don't want the AG-YAGHG (brick) either. I already have audio equipment and don't see the need for 3G-SDI for my use. But even though I'm "just" a learning hobbiest I'd like the best image and audio I can get within my budget. I'm a bit worried about the quality and robustness of the GH4's internal 4K recording. So if the GH4 could output 4K 4:2:2 at 10bit through the micro HDMI on the camera, and if there will be reasonably priced 4K recorders available, I might just go for one, if I felt the need. However, I fear Panasonic designed the GH4 to only offer recordable 4K out when you pair it with the AG-YAGHG. Take a look at this screenshot of the official specifications regarding the camera's HDMI output: 

Link to official GH4 specifications: http://www.panasonic.com/uk/consumer/cameras-camcorders/lumix-g-compact-system-cameras-dslm/dmc-gh4heb.specs.html

 

As I understand the specs for "playback" you would be able to connect the GH4 via HDMI to a compatible 4K display and play back anything you recorded internally on the GH4, including 4K content.

 

The specs for "monitor-through" read as follows: "4:2:2 8-bit / 4:2:2 10-bit (When 4:2:2 10-bit mode is selected, it is not possible to record motion picture or still picture on the SD memory card in the camera unit.)/information display ON/OFF (selectable)/Automatic down-conversion (4K → 1080p only)"

 

I understand those specs to mean: you can choose to output 4:2:2 8-bit to an external recorder or monitor and simultaneously record [4:2:0 8-bit] to the SD card. You can also choose to output 4:2:2 10-bit, but then you won't be able to record to the SD card at the same time. You can choose whether you want the on screen information overlay to be output or not. Anything output via the camera's HDMI port will automatically be down-converted to 1080p (whether you like it or not). As far as I can tell HDMI 2.0 will support up to 4K 4:4:4 12-bit, so I can't help thinking that this automatic down-conversion is done to create incentive for the AG-YAGHG. I'm no expert, so I could be wrong. So far I haven't been able to find the official specs for the addon, but it has been stated that it will offer a recordable 4K signal in 4:2:2 10-bit. The AG-YAGHG addon will probably be expensive and it is only compatible with the GH4, so it would not be easy to justify for someone like me. It could also mean that future GH-models will rely on the AG-YAGHG for optimal image quality - if this turns out to be the case for the GH4. I hope not. It would be great if the GH4's HDMI could do 4K out at 4:2:2 10-bit. That way, by investing in a future 4K recorder, those of us not minding dual audio and not needing 3G-SDI could gain access to the hightest 4K image quality the GH4 has to offer without the extra expence of the addon. Link to HDMI 2.0 specs: http://www.hdmi.org/manufacturer/hdmi_2_0/hdmi_2_0_faq.aspx#146

 

Still, the GH4 appears to be a nice camera, and I'm very much looking forward to reviews and sample videos from production models. Meanwhile I'll continue to enjoy my GH3.

[Andrew Reid]

Yeah looks like 4K is playback only and converted to 1080p when you use the HDMI output on the camera. Oh well. Brick it is!

[Oliver Daniel]

Great questions Hannah and awesome responses so far.

I'm in the exact same boat with the GH4. Don't really want the brick as it looks like a pain, but I definitely zest that 10 bit 4k.

It definitely looks possible to output the 4k from the HDMI port, but that's only if Panasonic would allow it, as they have to sell the brick too. Which in business sense, looks like Panasonic will force you to buy the brick to get that 10 bit 4k. It's a serious amount of data!

I find the 10bit 1080p to a recorder more interesting. Not too fussed it's not internal, even though it's more convenient. If the HDMI port down scales the 4k image to 1080p through the HDMI, would that effectively give you the downscaled 10bit 1080p anyway? (If that is your intention in post?)

Regarding the rig for the brick, I find it hard to believe that after all this effort Panasonic have gone to with the GH4, to make the inclusion of the brick a pain in the ass. I would of thought they would be closely working with third parties to make a rig specifically for the camera. The brick does have those mysterious screws.

I also have a feeling in my gut that the GH4 has been potentially designed to work with another Panasonic camera. It would be ace if they built a video camera body that included this entire package in one unit.

There will be a lot more to find out when the first cinematic footage is released of all the modes, and at NAB. :)

[paulraymaekers]

are there hdmi recorders for  1080  10 bit 422  for 50p ?

seems only 25p or 50i

[Andrew Reid]

FAQ started on the blog. Discussion continues here. Thanks everyone.

 

http://www.eoshd.com/content/12070/panasonic-gh4-profession-setting-faq