GH5 Game Over, Panasonic
- Thread starter Jim Simon
- Start date
joe12south
Veteran
Fair points. I do want to note that for the sample I posted, I would not consider it a particularly aggressive grade. Yes, it was a challenging scene in terms of dynamic range, but all I did was add a REC709 LUT (which you have to do for any LOG image) and adjust the curve from 50% down. For an actual deliverable, I would typically do a creative grade on top of that.
Over the years, I've gotten in the habit of trying to avoid subtle gradation. It's become so ingrained in my thought process when designing shots that I almost forget that I didn't have to do that when I used to work on film. Yes, I'm really old. ;-) We shouldn't have to be afraid of clear skies and beige walls (oh my how h264 beige walls!) All tools have limitations, but if I can afford to shoot RAW in camera and avoid this one, it is really going to be liberating. It is great that the GH-series supports external recorders so well, but they do add additional cost, hassle and fail points. I am usually director and DP. Attention I have to spend on gear is attention I'm not spending on the talent.
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Are you sure you get the results you get because of recording to the capture device (the Intensity as I presume). Using Natural sounds more plausible to me.
I have the Intensity Pro and I see no difference between footage recorded to my Pix-EH5 in prores HQ and uncompressed 10 bot YUV to the Intensity card, besides obviously file size. From that I conclude that whatever is send over it doesn't outperform the quality of what ProresHQ can handle.
Prores HQ/uncompressed 10 bit YUV/uncompressed 10 bit RGB (pick your flavor) is only marginale better (8 bit vs 10 bit) than the H.624 from the GH4. It still carries the same imprint from a blocking scheme, you so well described, after I choke it. If we really got clean data from the sensor those imprints should have been gone and that is not the case in any of the tests I ever did.
Joe12South screen-grabs shows the same imprint in both the Prores and the H.624 PNG’s.
http://www.bunkweb.nl/plaatjes/prores_vs_h.624.png
It would very much surprise me if the two would behave differently in their marching pattern when we look at a couple of frames in a row. Pretty much as we can see in the GH5S clip, of my YouTube attempt, on the back of the guy smoking a cigaret. So whatever the GHxx sends over it’s not clean data. Maybe Joe is willing to test it or share a couple of more frames from that clip so we can test it ourselves.
Thomas Smet
Veteran
Yes there is a difference. In particular when it comes to mosquito noise around edges which even ProRes HQ can display when you have edges of flat colors. Doesn't matter if you use Natural or log. DCT mosquito noise is DCT mosquito noise no matter what. ProRes HQ can macro block as well but its extremely rare. I see it a ton on ProRes LT and occasionally on regular ProRes. HQ is pretty robust however but it stills suffers from other DCT artifacts like mosquito noise. Remember ProRes is basically jpeg and while jpeg can look pretty good for general viewing it does still have artifacts compared to Tiff or raw photos. I'm also using the GH4 with its 1:1 sensor output and no extra processing involved. Perhaps the GH5 itself is causing that extra ringing or mosquito noise around the edges. I'm capturing external HD by letting the camera downscale UHD to HD via the HDMI port which results in the least amount of in camera processing.
With that said all of this is really splitting hairs and few high end productions have ever considered ProRes HQ not good enough. In fact the ProRes4444 formats use the same level of DCT compression and have the exact same mosquito noise and that format is now used for a lot of Hollywood productions instead of raw. So we really are splitting hairs now. If a movie in Hollywood that actually earns money at the box office is ok grading the compression of ProRes then I'm pretty sure it will work for all of us as well. The only difference between ProRes HQ and ProRes4444 is the added 4:4:4 color and 12bit color. Compression wise the macro blocks and mosquito noise is the same. You have to move to ProRes4444 XQ to reduce the compression amount which tends to be larger than what a raw format would provide. If we eventually get more ProRes raw options the ProRes4444 XQ would largely be a pointless format unless somebody actually uses a 3 chip 4k camera.
Thomas Smet
Veteran
I would still love to see if the GH5S fairs better due to a lack of in camera scaling. Sharper edges always encode with worse ringing and mosquito noise and have to work that much harder in general. Cinegal found the 400mbps on the GH5S to hold up very well compared to the ProRes on the Alexa Mini. Could the encoder be improved on the GH5S or could the different processing affect what the encoder can do vs the GH5? A lot of people have been fixated on low light from the GH5S and pretty much ignored what it meant to go back to a 1:1 sensor camera and what that could mean for more natural detail and how well the encoder can perform. I believe there are more subtle quality differences between the GH5 and GH5S we need to pay more attention to.
In terms of the extra noise reduction on the GH5S at high ISO levels I think that is a given and using noise reduction in post on raw from the Pocket will likely kill just as much texture and fine detail. Noise is noise and once you get to a certain level you can make the image look clean but you will make it plastic looking in the process. Serious production should still use lights to attempt to keep the ISO at more realistic levels on the GH5S and on the Pocket. The one advantage of the GH5S is from a videography point of view what comes out of the camera is already cleaner without any extra needed processing. On a 4 camera shoot that means a ton vs doing noise reduction in post on a longer production which could take days to perform. Even if the post noise reduction can look a little bit better thats just something a lot of videographers cannot spend the time doing. The GH5S may have more aggressive noise reductio nat higher ISO levels but I think thats a good thing for the people that need the low light shooting the most.
If a narrative production is shooting ISO 6400 just because they can then they have a lot more to worry about than just the plastic look affecting the professionalism of their work.
I believe that modern h.264 and h.265 are using PERCEPTUAL codecs in that they throw away the parts that we don't really (in theory) perceive, same process is applied to AAC and all of it's derivatives (HE-AAC, etc.). Then I think (again my memory is a little weak on this as it's been more than 10 years since I was researching this topic) that they go into the motion analysis to determine the other parts that need to be encoded (did the pixel move or change? if not then code it as a repeat from the previous frame). I never had a decent grasp on the DCT vs. Wavelet technology, but most of the devices I was using were DCT based (cameras with DV or DVCPro, etc.). Mr. Powell could probably school us on this.
combatentropy
Veteran
Yes, you have zoom far in to see the difference. At least I do. Some have mentioned secondary color correction being hard, but I'm curious to see proof.
Don't get me wrong, I would love to shoot only in RAW. It seems everything the manufacturer does to the image I would rather them not. But I'm waiting for memory cards to get to be around $30-50 for a terabyte (1 hour of 4K RAW).
Best set of videos I've seen explaining DCT, http://www.dvxuser.com/V6/showthread.php?360018-How-Image-Compression-Really-Works
Approachable explanation of Wavelets from the guy who wrote Cineform, https://gopro.github.io/cineform-sdk/ (see Wavelet Transforms).
Thomas Smet
Veteran
ProRes raw is the step in the right direction where I think it will start to make more sense. Media cost is one thing but there is also the workflow needs and the performance of raw to take into consideration. I downloaded some ProRes raw material that plays back perfectly fine on a 2015 MBP. Thats really impressive and a nice future path for raw. I think when ProRes raw takes off a bit more it will make raw a more realistic workflow for a lot more people other than just film makers.
Thats very encouraging. I may start recording open gate and converting to 1080 prores HQ in post.
John Brawley
Well-known member
Ahh, that's actually a HUGE difference.
That's not an insignificant difference and is the real reason why ProRes 444 is the default origination codec of most of the narrative TV drama you see that isn't a Netflix Original.
Like the way 8 bit to 10 bit is a big jump ? Make that jump AGAIN when you go to 12 bit. (RAW or ProRes)
JB
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Use a bicubic scaler to not introduce any additional sharpening
Btw, just tried the A7 III earlier.
Set sharpening to -7, S-Log 2 with higher saturation. Colorspace conversion to REC709 (with some ARRI magic) leads to a stunning image without any banding nor visible sharpening. Looks incredibly organic. Great rendering of fine detail as well.
Use a bicubic scaler to not introduce any additional sharpening
Btw, just tried the A7 III earlier.
Set sharpening to -7, S-Log 2 with higher saturation. Colorspace conversion to REC709 (with some ARRI magic) leads to a stunning image without any banding nor visible sharpening. Looks incredibly organic. Great rendering of fine detail as well.
How do you think it compares to the image coming out of the GH5?
Thomas Smet
Veteran
No duh it is to some people. I was talking about image compression in terms of macro blocking and mosquito noise which was the topic of the discussion. Beyond the 4:4:4 and 12bit color difference the compression level itself is roughly the same. If one wants to eliminate that mosquito noise and extra potential for macro blocking they need to go to uncompressed, raw or ProRes4444 XQ.
John, have you ever shot with the Sony PMW-F3 back in your past? Wonder about your thoughts with it, and how 444 from the F3 compares with shooting with it at 422? (which is normally all I ever do with it)
John Brawley
Well-known member
I'm afraid I've never shot it. Only F55 in Sony lately. Keen to look at Venice soon.
JB
Bern Caughey
Veteran
Spent a few minutes with a prototype BMPCC 4K yesterday during Cine Gear. Rolling Shutter seemed well controlled, & on par with the GH5, & GH5S.
Nice it looks like these small cameras are stepping it up in terms of rolling shutter. GH5, A7III, and now Blackmagic.
joe12south
Veteran
And that's all you're going to say about it? ;-)
Dan Keeble
Well-known member
This bad boy should be out next month! Gonna shake things up I think.