KnightsFan

@sanveer Last time we talked about this, I actually did that. I looked up every single C5D article that mentioned a dynamic range and compiled them into a spreadsheet. Turns out the only discrepancy was with the A7s2. I contacted C5D about that, and was told which articles had used a 4k to 2k downscale. The 4k downscale increases DR on the A7s2 from about 10.6 to 12 stops. After that was cleared up, I couldn't find any other significant problems. Now, it appears that they always list the resolution and whether any downscaling was done.

So those of you who think C5D's results are inaccurate, what do you think is causing that? Are they intentionally lying? Is the imatest software glitching out? They publish their methodology, and the images they use with imatest. Are the images fake? They've even gone out of their way to explain different ways of testing dynamic range (https://***URL not allowed***/canon-measured-15-stops-dynamic-range-c300-mark-ii/) and now they often publish at least two values, for SNR = 2 and SNR = 1. These are not subjective tests. You can very easily copy them--they explain the setup, the lens used, the exact ffmpeg command to extract i frames, and how to setup the software. If you cannot reproduce their results with the same setup, then publish your results and let us know. But until then you really have no authority to call BS. Do you really think they would go through the trouble to be the only site that conducts extensive, objective DR tests, and then make up their results? If so, it should be very easy to prove, instead of bashing them on internet forums.

So it was recorded internally in ProRes or transcoded?

Anyone know if the e2 was shot internally or not? Its a prores 422 file, i wonder if it was recorded internally or externally or transcoded.

I can't say this test is at all conclusive. Neither camera clips, so you can't really see what the DR limit is on either camera. It looks like the Arri keeps the highlights a little lower on the waveform, but the Z cam's waveform shadows are also at a higher level so it could just be an exposure difference. The different field of view and angle make it hard to tell. I'm still going with "everyone exaggerates by 2 stops except Arri" so 15 for Z Cam is really more like 13 (as measured by Arri). I do think that the color on the Z Cam is phenomenal. The real conclusion is that the Z Cam's footage is really good enough for any cinematic purposes. @webrunner5 they are both UHD I can't say I agree. The Z Cam actually looks like it has less noise. Arri definitely has more chroma noise. However, the Z Cam's depth of field looks shallower, so they might have a faster lens and a lower ISO.

I wanted to test an H.265 encoder where I can adjust parameters and see how they effect size and quality. I didn't publish all my tests, but I've actually tried dozens of combinations of settings, both from ffmpeg and Resolve, and also tried different ProRes and DNxHD encoders. The NX1 specifically has a hardware encoder from 2014 designed to run in real time, whereas I was more interested in how good H.265 could look if you give it, say, 68 second to encode a 3 second clip. Hardware encoders are often not as high quality because they have a more limited number of algorithms available, and can't be updated as the specification is changed. Since 2014, we have had several updates to the HEVC standard. The test you propose only compares the NX1's encoder vs. the Ninja's, not the possibilities of H.265 as a distribution codec (which was my interest). Furthermore, I do not own a Ninja. In fact, one of the main reasons I didn't invest in one is because, through my tests, I have not seen ProRes as a huge benefit.

Exactly. Generally, you get less noise if you raise the gain by a stop while shooting, and then pull it down a stop in post, though you can lose highlight detail. Assuming that the "gain" is actually gain and not just metadata, like it is on most Blackmagic cameras.

You know, I just used Resolve's H265 encoder and I can't see much difference compared to ffmpeg on the car scene I've been using. But I am 100% sure I got some really bad results on a Resolve project I exported not too long ago. Maybe that car scene is just really easy for H265--though to be fair, I downloaded it for these tests before I had seen it. Someday I'll have to borrow an Ursa and shoot my own tests. I'm also interested in finding out whether coming from a 444 source improves a 422 file vs. coming from a 422 source.

Cool, less difference now, but ProRes still looks like it retains more detail. I've never liked the results from Resolve's H.265 encoder, though, and I think ffmpeg's generally produces better results. But clearly H.265 struggles a lot more with this busy scene than with the one I used.

What encoders did you use? Your H.265 is 16 Mbps (Mine came out to 22), not 100. It's also 420 instead of 422, so that could be part of the chroma difference. But yes, with your settings the ProRes HQ certainly is much better!

ProRes is built for editing speed, whereas H.265 was designed to maximize quality on low bitrate streaming, especially 4k and 8k. I knew that at some lower bitrate, H.265 would retain more data than ProRes, but I was surprised that it does so well with just 1/5 the data. Of course, it took 6x longer to encode! I would love to see your results, if you publish. Keep in mind that not all encoders are equal, and H.265 has a LOT of options. ProRes is easier in that regard, as you just pick from Proxy, LT, Normal, HQ, and XQ with predictable size and quality. Edit: the difference in detail is negligible between ProRes HQ (180 Mb/s) and the H.265 file. Also I didn't see any real difference between ProRes and DNxHD at equivalent bitrates.

Spoilers for anyone who wants to do a blind test! It turns out that A is ProRes and B is H.265. As @Deadcode points out, B (H.265) has noticeably more detail. However, the ProRes file retains a tiny bit more of the chroma noise from extreme shadows the original video. As you can see in the 300% crop below, all that sparkly noise is simply gone H.265, and while the ProRes has some obvious blockiness, you can still faintly see the noise. This is of course a VERY extreme grade (see the curve from Resolve). With extreme grades the other direction, the ProRes looks better up until the VERY extreme, when its blockiness shows. As I said before, encoders have many options so this doesn't mean much for cameras. However, if you are uploading to a site with file size limits, H.265 is a good option. Also, as @OliKMIA pointed out, this is not a comprehensive test: it's 3 seconds of HD, and only looks at one scenario. This shot is quite stable, so the interframe flavor of H.265 that I used has an easier time. Shakycam will reduce the quality of H.265. Furthermore, the encode time on ProRes was significantly less: 11s vs 68s. I could have used a faster preset for H.265 which would speed up the encoding at the expense of quality (my guess is that cameras, tasked with real-time encoding, are not as good as the preset I used). On the other hand, I have a 2013 CPU. Perhaps newer CPUs with hardware encoding could narrow the gap? I'm not sure. If you want to look at the original files (before I turned them into 380 MB monsters!) One final note: I accidentally encoded both with AAC audio, so ~6kb of the file size of each is an empty audio track. ProRes: https://drive.google.com/open?id=102Ivc9Xa1Z7mPzCK8TgTqwh2GExMPOkZ H.265: https://drive.google.com/open?id=1NxMofYvrHcP6DHx5VECRwMNw8qA4KXOD

@thebrothersthre3 I find them to be equal for all practical purposes, even with extreme grading (by extreme I mean waaay out of the realm of usefulness). There are differences, but neither seems more accurate. I haven't tried green screening, and that would be an interesting test, but I don't have a RAW camera so I'm limited in the scenarios I can test. And naturally it defeats the purpose of the test if I start with anything less than a RAW file. Interestingly, despite having a hard time making any substantive distinction between the two, when comparing the PSNR (peak signal to noise ratio), ProRes is higher than H.265 at this compression level. H.265 needs to get up to around 50% of the bitrate before the average PSNR is the same--and even then, the PSNR on I frames is higher than ProRes, but the PSNR on P and B frames is lower. That's to be expected. I could also push the preset to be even slower, or use two pass encoding for better results on H.265 as well. No, I did RAW -> Uncompressed RGB 444 And then Uncompressed -> H265 -> Uncompressed And also Uncompressed -> ProRes -> Uncompressed I did it this way so that I would not be limited by Resolve's H.265 encoder, and so that I could do PSNR tests from Uncompressed, without having to futz with debayering messing up the PSNR comparison. I did a short clip to keep the file size manageable at only 380 MB each. I originally did 4k, but I figured no one wanted to download that! If there is interest I am happy to do more extensive examples.

I did a quick comparison between ProRes and H.265 encoding, and thought I'd share the results with everyone. I grabbed some of Blackmagic's 4.6k RAW samples and picked a 3 second clip. In Resolve, I applied a LUT and then exported as an uncompressed 1080p 10 bit RGB 444 file. This is my reference video. From this reference file, I encoded two clips. One clip is H.265, and the other is ProRes SQ, which I compared to each other and the reference video. The reference video (which I did not upload) was 570 MB. One of these files was created from the reference file using "ffmpeg -i Reference.mov -c:v libx265 -crf 20 -preset slower -pix_fmt yuv422p10le H265.mov". The file size is 7.81 MB (1.4% of the reference) The other file was created using "ffmpeg -i Reference.mov -c:v prores_ks -profile:v 2 ProRes.mov". The file size was 44 MB (7.7% of the reference, or ~5x the size of H.265) In order to keep the comparison blind, I then converted both the ProRes and H.265 files to uncompressed 10 bit 422. So you shouldn't be able to tell which is which from the metadata, file size, playback speed, etc. You can download these files (380 MB each) and do extreme color grades or whatever stress tests you wish, and compare the quality difference yourself. https://drive.google.com/open?id=1Z5iuNkVUCM9BgygGkYRXizzr6XnSXDK7 https://drive.google.com/open?id=1JHkmDKZU4qdS7qO_C0NwYH2xkey0uz7C I'd love to hear thoughts or if anyone would be interested in further tests. Keep in mind that there are different settings for H.265, so this test doesn't really have implications for camera quality. since we don't know what their encoder settings are. However, it could have implications for intermediate files or deliverables, especially to sites with file size limits.

C5d puts the alexa at 14 using their SNR = 2 measurement. I agree. But you cant blame z cam when everyone from sony to blackmagic exaggerate their dr. Only arri has the godlike status that allows them to be honest and still sell products.

It's actually been in and out of stock a few times at B&H.

If the signal is lower, the same noise will be more apparent. Or perhaps Nikon is doing some automatic corrections as suggested above.

I don't know about holding back, but it's all about priorities, I think. Z Cam is a bleeding edge company. They make 360 cameras and are actively working on integrating AI into their cameras. Z Cam has a smaller community, and many owners at this point expect bugs and workarounds--it's the price of using bleeding edge. Blackmagic is focused on bringing cinematic imagery at a low cost: they care more about color science and integration into pro workflows than they care about high frame rates and next gen tech. Their target audience is more likely to have learned on film than Panasonic or Z Cam. The P4k is also significantly cheaper than the other cameras, the fact that it even competes spec-wise is impressive. Panasonic is orders of magnitude larger than either company, and needs to compete with the other giants (Canon, Sony, Nikon), both today and tomorrow. Their products need to have near 100% reliability, and be easy for consumers to use. A single bug could kneecap initial reactions to a product, permanently damaging their reputation. Why spend the R&D money on 4k 120 if Sony isn't, and when that money could go towards QA? Of those three companies, it seems to me that Z Cam has the most incentive to innovate with technology. It wouldn't surprise me one bit if Z Cam ends up with the best specs.

I haven't seen any third party tests, but my guess is that they are exaggerating by 2 stops, like most manufacturers. Or, to look at it another way, Arri under-exaggerates by 2 stops. It's kind of like Canon claiming 15 for the C300, although Canon's 15 is measurably less than Arri's 14. Also a lot of the footage I've seen of the WDR mode has bad motion artifacts, so it's probably unusable except for really static shots.

Not officially. They are still waiting for licensing, but a few users have found a way to turn on ProRes via a sort of hack. Those independent sources do confirm the camera's abilities, though. It seems pretty unlikely to me that they are using another camera for their test footage. They are planning on implementing Raw in the E2 alongside ProRes and H.265. Granted, the P4K will have BRaw, which I predict will be better than Z Cam's Raw format.

You can. I thought it was only in all I, but if you can do long gop in 400 then even better.

Prores 4k is 500 mb/s, more than double the 200 on the xt3 which looks just as good to me. I may do some tests to see what the actual difference in accuracy is. The xt3 400 mbps is all i, which is significantly less efficient.

Give h265 the same or even Half the data rate as prores and then compare. 10 bit 422 h265 at a high bitrate looks REALLY good to me.

I shot with an xt3 and an nx1 on a recent project, and while the xt3's footage was visibly better in 4k 24 when i pixel peeped, i really can't say it really made a difference for my project. Of course having that quality in higher frame rates and a faster readout are real benefits, but even the nx1 peaked for diminishing returns in terms of color, compression, and dynamic range. At this point the biggest upgrades i want are for workflow: timecode, ergonomics, false color, and such.

No problem! Good luck!