C100: AVCHD better than Atomos Prores?

V

Vectorizer

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Hi folks!

Some time ago, i did a test with my C100 and an Atomos Ninja Star in order to find out, how much better prores recording is than the internal AVCHD Recording. I was quite surprised by the result and thought, you might be interested in it, too:

Here it is:
https://www.youtube.com/watch?v=E92jDQpou4Q

edit: As requested, a little summary :-) : The Prores codec is not that far superior than i thought it would be. In fact the 422 setting on the Atomos Star gives me worse image quality in several situations than the internal AVCHD. Only the HQ setting is superior to AVCHD in every situation. The video focuses on spatial artifacting that occurs in each Codec and gives several examples.


Have a good day!
 
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ProResHQ ONLY! It's odd that regular ProRes422 can't look better than AVCHD, but that's just the way it is with the C100. For normal shots the in-camera codec works great, but when you really need to push and pull, when grading (or fixing!) ProRes can be a real lifesaver. I've had very good results wth Neat Video combined with ProRes422HQ.

I wonder, does this fact he true for other types of AVCHD cameras?
 
Great video thanks.... I've seen it before. I think your video clearly shows the ProRes HQ is the winner, it's just a surprise that it's not so obvious. It would be nice to see a video showing both codecs during and after grading.
 
Thank you!

It's true that artifacts can be also caused by components of the signal chain: Image Processing in the camera, HDMI cable etc. But i cannot be the case here, otherwise the artifacts would also show up in the Prores HQ Material, right?
So the artifacts emerge in the prores encoding in the Atomos and should be the same with every videosource and every Camera. And as i assume that Atomos builds the same Encoding algorithms in all their devices, i think you get these results with every Atomos recorder, not only the Ninja Star.

I was contacted by an employee of apple because they wanted to examine my source material to further develop the prores algorithms. I took the chance to ask him some questions but unfortunately he couldn't (or didn't want to) answer the question, if the Prores Encoding algorithms are standardized. Meaning, you would get the exact same results from Aja, Blackmagic Design, COnvergent Design, etc.

If that is NOT the case, MAYBE its just an atomos thing and caused by their prores implementation.
I take this into consideration because some people reassured me, that these artifacts do not appear in their 422 Material...

Another thing i think about is: Why do people think prores saves them from all evil in the CC process? Sure, if you have an 10bit source, it's a quantum leap. But the biggest drawback of my setup is, that the C100 can only feed 8bit into the recorder. In the push/pull process of CC all you want to avoid is banding and spatial artifacts. But AVCHD is also 8bit and thus gives you the same RGB values so banding is most likely to occur to the same amount with both codec. Spatial artifacting i covered in my video that shows, that especially prores 422 is not always better than AVCHD...

So i think that when youre using neat video to artificially stretch your color values, your results in CC should also not be that different with AVCHD and Prores. I have the impression, many people regard me as an heretic when i state this theory! ;-) I am thinking about making a video about the difference of AVCHD and PR in the CC process... should be interesting as well to see, if my thesis is correct. ;-)
 
I have heard some people mention that Atomos' ProRes implementation may not be so good. Not sure if this is true or not, though.

I'm sure if you converted the HQ stuff down to 422 it would be fine.
 
I wouldn't say it saves us from all evil :) but I can without a doubt say that ProResHQ behaves better for me when applying significant corrections. Blacks especially have less artifacting, along with the usual bright reds and such. This is the 4:2:2 and bitrate at work of course, not 8bit/10bit advantages. I do think that capturing the fine noise with ProResHQ helps with the banding you mentioned, and if removed, (in a 10-bit editing environment?) should result in smoother gradients, though perhaps artificially.

All said, the biggest reason I use ProResHQ (for certain gigs) is for capturing finer moving detail and improving the appearance of occasional artifacts in the blacks of the AVCHD.
 
Thanks for this. I almost bought an Atomos with my C100 but I'm becoming increasingly glad that I didn't. I don't really shoot videos that require heavy grading, and not needing to worry about an extra piece to my rig when I'm run and gun shooting is huge for me - it's largely why I upgraded to the C100 from my DSLR. That fact that we even need to zoom into these videos and pixel hunt for differences just shows that the vast majority of people will not notice the difference.
 
I defense of the Atomos I do like the display (Blade) and the hard drive space. It's very convenient to get from the camera onto your computer. The ProRessHQ does look better to my eye. I have seen a few other comparisons where the difference was more significant, than is this video.

I do think that the ultimate comparison test would be how well it holds up in any kind of Color grading.
 
I would love to see if your findings are the same with other companies. Especially interesting that Apple contacted you regarding it, meaning they don't like what they see! :D
 
Hi, Vectoriser. I assume then, that you are Kurt. We can resume the discussion here.

Vectorizer said:
It's true that artifacts can be also caused by components of the signal chain: Image Processing in the camera, HDMI cable etc. But i cannot be the case here, otherwise the artifacts would also show up in the Prores HQ Material, right?
Click to expand...

A fair assumption, but you have yourself proven that that isn't the case. The ProRes 422 looks bad, while the ProRes 422 HQ doesn't.

I DO assume that all Atomos ProRes 422 encoding is the same on all of their devices—and that is worrisome. I would not use an Atomos recorder with ProRes 422 without check this first. And even if the 422 HQ looks good, I still wonder if it reaches the full quality or if it also has issues that are well hidden. With Shogun just released and ProRes being one of the main features on the external recorders, needless to say, we want it to work perfectly.

There IS the possibility that this is caused by something in the ProRes protocol. But ProRes has been around a while and I've never seen this before. But it's good that Apple also looks into it. I'd like Atomos to speak up as well.

And like I told you in the YouTube comments: ProRes, when implemented by Apple (FCPX), does not have these issues. I routinely convert high bitrate, 422 mjpeg material to the normal ProRes 422 in FCPX. All of the details from the source material is maintained. One difference here is that my source material is intra-frame, just like ProRes, while AVCHD is inter-frame that needs to be re-assembled and then encoded ot ProRes on the fly.

Anyway… the big takeaway is simply to be aware of the issue so that it can be worked around. Your video did great in putting a light on that.
 
Vectorizer said:
Another thing i think about is: Why do people think prores saves them from all evil in the CC process?
Click to expand...

I think you covered most of the benefits in your previous post: upgrade to 422 instead of 420, avoid inter-frame spatial tearing by upgrading to intra-frame. Resolving finer detail with a high bitrate reliable codec. These are all valid upgrades.

But they won't help with banding, which is another major issue with consumer 8bit codecs. I've said it before: all major NLEs do their color manipulation in 32 bit floating point space, so I certainly don't belong to the crowd that thinks 8bit out into a 10bit codec is an upgrade in itself. I list the real upgrades above.

I would have loved if the C100 mkII did 10-bit out, and I think it should. If the C300 mkII doesn't at least offer 10bit out, Canon has lost touch with reality. I think I'm fine with 8bit internal recording, but going forward, this/our user segment will need 10bit out.
 
The C300 Mk1 should have come with 10bit in camera in the first place. If the Mk2 only outputs 10 bit and is still 8bit in, I will be a shame I ever bought a Canon product.
 
Doug_EX said:
The C300 Mk1 should have come with 10bit in camera in the first place. If the Mk2 only outputs 10 bit and is still 8bit in, I will be a shame I ever bought a Canon product.
Click to expand...

While the camera out needs 10bit, I'm still pondering the options of internal recording. I think it depends on what codec choices Canon has.

The C100/300s have been popular documentary cameras. It's the kind of camera you can take on an adventure and get great results. No worrying about batteries and media. There is something to be said for a camera where you can hit record and just let it keep running. Especially if the C300 mkII would present itself as the first 4k camera that looks really good out-of-camera where you can shoot all day on a few small batteries to a few small memory cards.

Once you start rigging and going for more of a production look it's a non issue to pick up the files off of an external recorder like Shogun or 7Q+
 
I've seen a number of conflicting reports on the Atomos. Most however tend to agree there is an advantage in the ProResHQ over the AVCHD. In daylight shots there seems to be little difference but more challenging situations is where the Blade comes out on top. Here is another review with examples..... go to 5:30 into the video.

https://www.youtube.com/watch?v=fSyl2LeSGOA
 
Also as we are heading into the year of 2015 with technology going bezerk you'd expect the current AVCHD to hold up against an 8bit ProRes. Cant wait for 2016 and beyond :)
 
BeeHop said:
If your going to go to the effort of using an external recorder it has always made very basic sense to me to use the highest quality setting. Otherwise don't use one.
Click to expand...
I totally agree with your statement! Just use the HQ setting!!!
 
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