Have faith in small Chinese manufacturers. They seem to make pretty much anything anyone is willing to buy, regardless of how niche.
GH4 Panasonic GH5 coming in 2017
- Thread starter Dan Keeble
- Start date
filmguy123
Veteran
Can someone help me understand Hybrid Log gamma, and why it shouldn't be used to shoot everything? Driftwood in the chat says it looks amazing.
I would be interested in hearing more about it too. Did you read the wikipedia article that I linked in the previous page of this thread?
joe12south
Veteran
The wikipedia page does an okay job explaining it. It's literally what the name says...part of the signal uses a log curve, part of the signal uses a gamma curve. In an oversimplified nutshell, it's a way to squeeze a wider tonal range into a REC709 signal. It's less extreme than your traditional LOG curve, designed for broadcast. Similar to a LOG image, it will look wrong until it is unsqueezed.
If I'm not mistaken, DaVinci Resolve already supports the curve, and HDR display, but I have no footage with which to test.
joe12south
Veteran
Even better article, straight from the horse's mouth: http://www.bbc.co.uk/rd/projects/high-dynamic-range
Thomas Smet
Veteran
Maybe eventually the Hybrid Gamma could potentially be used as a poor mans version of log from the GH5 that you don't have to pay for. I wouldn't want to grade it manually but with a proper lut or software handling the Hybrid gamma it could possibly be used to get more of the full dynamic range of the GH5 without having to use V-log.
It's really designed to use with HDR displays and not meant as a log format to manually grade. If somebody has a HDR display they can use this profile and get extra range vs just a rec709 profile.
It's really designed to use with HDR displays and not meant as a log format to manually grade. If somebody has a HDR display they can use this profile and get extra range vs just a rec709 profile.
joe12south
Veteran
HGL can comfortably represent 16 stops of DR inside of a REC709 compatible 10bit signal. If it is widely adopted as a standard, it will actually make for more consistent grading than manufacturer specific LOG curves we use today, which are all over the map.
Like LOG curves, HGL is a hack, but it's a clever hack, indeed.
Like LOG curves, HGL is a hack, but it's a clever hack, indeed.
filmguy123
Veteran
I guess i meant why would I want to use that INSTEAD of vlog, assuming I own vlog as well? I don't understand why it is even on the GH5 since it caps out around 12 stops DR? Wouldn't it always be preferably to simply shoot in vlog?
I'm probably missing something here, I bring it up because I was a bit thrown by Driftwood's statement that HGL looked "f***ing awesome" on the GH5. I had assumed it would just be there to match cameras log curves with something like a Red Weapon if using it in a larger production environment.
I'm probably missing something here, I bring it up because I was a bit thrown by Driftwood's statement that HGL looked "f***ing awesome" on the GH5. I had assumed it would just be there to match cameras log curves with something like a Red Weapon if using it in a larger production environment.
filmguy123
Veteran
in other news: driftwood stated in the chat that the new GH5 AF features work in VFR mode, as well as 4k 60p 
He also seemed very pleased with ISO performance. When asked if ISO 800 might be the new ISO 400 he said "sure! I'm actually impressed the performance much higher than that". Take it with a grain of salt until it's put through paces a bit better, and judge for yourself (and I'm assuming DR still decreases with each ISO jump?), but good to hear that shooting a dim lit wedding on a GH5 may have just gotten a whole lot easier.
He also seemed very pleased with ISO performance. When asked if ISO 800 might be the new ISO 400 he said "sure! I'm actually impressed the performance much higher than that". Take it with a grain of salt until it's put through paces a bit better, and judge for yourself (and I'm assuming DR still decreases with each ISO jump?), but good to hear that shooting a dim lit wedding on a GH5 may have just gotten a whole lot easier.
I see. Maybe that's why the Sony overheats...
joe12south
Veteran
Hard to say exactly until we get to use it, but in theory it isn't as compromised as V-LOG L, and is optimized for a 10 bit bucket. That is to say it uses more of the available bandwidth. It's also easier to monitor without a LUT...the luma will look more normal, but desaturated. But by in large, I would expect end results to be very similar. The main advantage of HGL is as a broadcast standard.
Here is some footage I shot some time ago that was designed to push V-Log and the GH4 in low light.
https://drive.google.com/folderview?id=0BzXpNy2MdkE6V1hZN1k4UHJFRTQ
Let's put it this way:
To me, 10-bit ProRes/DNxHD footage at 1080p looks better and is sharper than 8-bit internal V-Log at 4K.
philiplipetz
Veteran
The illustration shows three pins, for the audio they added a fourth pin that was not on the gh4
joe12south
Veteran
That's highly subjective. For many, 10 bit 4:2:2, 400 Mbps, waveform/scopes and dual cards will do the trick ...others will still feel the need for even less compression and a more edit friendly codec (like ProRes.)
I think we can safely say though that an external recorder will no longer be a requirement to use V-LOG L.
Keep in mind that 10-bit 4:2:2 internal recording is not available for 2160p60 (or 2160p50). But the GH5 is capable of outputting 10-bit 4:2:2 at 2160p60 over HDMI (with internal recording disabled). So if you are interested in maximum quality at these higher frame rates, you'll still need an external recorder to capture it.
Thank you!
Thomas Smet
Veteran
Yeah it depends. When the camera first launches the 10bit will be limited to 150mbps. 400mbps is only coming later in the year. ProRes422 HQ 4k 24p is 880mbps and the internal all-I format is 400mbps. That is a pretty significant amount.
Think of an all-I format like saving a jpg image. The different levels of ProRes are like saving a jpg image at 65%, 75% or 85% quality. These are rough figures just to get a perspective of whats going on. 400mbps would be more like a jpg at 50% quality which is ok but not great. Video using this type of compression tends to show the compression artifacts and mosquito noise a lot more since it dances around and moves around edges and fine details. The lower the data rate the more artifacts you will see in the image. Not the same kind of artifacts as an IPB macro frame but they are still artifacts just like a badly compressed jpg image.
Remember on the GH4 it is highly recommended not to use the HD 200mbps all-I mode because it just doesn't look as good as the IPB modes. 200mbps should be plenty for HD but alas it was not on the GH4. So far Panasonic doesn't exactly have a good track record when it comes to all-I formats. I hope they have improved on them but past history tells us they will not be spectacular. The 72mbps HD mode on the GH3 was kind of ugly as well.
It will no longer be an absolute must to use an external recorder but if you are working on a serious productions and something you want to be proud of you want to still consider it.
A few other things to keep in mind.
1. While the GH5 may have some scopes they are tiny on a tiny 3.2" LCD. An external monitor gives you much larger scopes that are easier to see fine details. The scopes also have to be turned on via the camera menu and switched in the same menu which can take more time vs a simple external monitor menu system.
2. False color is an extremely useful tool for setting exposure with log. The GH5 does not have false color.
3. The GH5 LCD is small and still doesn't show the large critical resolution to nail focus at a good 7" monitor. Professionals were using external monitors long before they used them to record external material.
4. ProRes is a tried and true format used by a lot of people. Hard to really go wrong having ProRes files in the Mac world. There is a good reason why BMD, Varicam and ARRI use ProRes as a recording format in their cameras outside of raw.
5. An external recorder like the Flame is a 10bit FRC display which means it will be easier to judge 10bit colors on the monitor. Shooting with just the GH5 will get you close but it will never be a 100% perfect judge of what you are shooting.
6. An external recorder can be used not directly attached to the camera. For example on a stand with a long HDMI cable run. I find this extremely useful at times when I can sit in front of the camera and bring the monitor with me to see how the lighting and setup looks.
7. External is future proof and can move around to other cameras. If you decide you don't like the GH5 and want to move to another camera you can still record the same format and have the same monitoring tools you are used to.
combatentropy
Veteran
Well, their pro division has a good track record. AVC-I compressed 10-bit 4:2:2 HD to 100 Mbps, and it was visually lossless. Now that was HD, so for 4K I would think quadruple the bitrate (400 Mbps) would be plenty (you don't even need to always raise the bitrate to the same degree that you increase the frame size or frame rate, because often the compression is often more efficient across bigger samples).
Bitrate without mention of codec means little. Is it 400 Mbps MJPEG or 400 Mbps AVC or 400 Mbps latest-and-greatest? It could very well be good ol' MJPEG. Even then, according to my calculations at 24 fps that is only a 7:1 compression ratio, which is typically what I get when I compress a JPEG at quality 90.
I haven't used the GH4. This is just armchair mathematics. Just love partial information trickling out from manufacturers
Thomas Smet
Veteran
Well, their pro division has a good track record. AVC-I compressed 10-bit 4:2:2 HD to 100 Mbps, and it was visually lossless. Now that was HD, so for 4K I would think quadruple the bitrate (400 Mbps) would be plenty (you don't even need to always raise the bitrate to the same degree that you increase the frame size or frame rate, because often the compression is often more efficient across bigger samples).
Bitrate without mention of codec means little. Is it 400 Mbps MJPEG or 400 Mbps AVC or 400 Mbps latest-and-greatest? It could very well be still MJPEG. Even then, according to my calculations that is only a 7:1 compression ratio, which is typically what I get when I compress a JPEG at quality 90.
I haven't used the GH4. This is just armchair mathematics. Just love partial information trickling out from manufacturers
If it was AVC-Ultra I would be ok with that but it isn't. It is their regular AVC-HD encoder since it needs to encode the other AVC formats. Besides that doesn't explain why the 200mbps all-I format was so bad on the GH4 when AVC-Intra was already around and looked good at 100mbps. If it is in fact AVC-Ultra which is why we have to wait until later this year then that would be really good.
AVC-Ultra 4k up to 30p just so happens to be 400mbps. Hmmmmmm...