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Matt Perks

Atomos Ninja V - Problem with Input Gamma?

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Howdy!

 

So, I've just received my Ninja V today and there's a big problem... it's clipping the input assuming that it's limited RGB (16-235) rather than full RGB (0-255), and the problem with that is that my XT-2 outputs the latter, so there's some awful butchering of the highlights and shadow areas.

 

Does anyone have any suggestions? The input gamma has only one option: rec.709.

 

I've confirmed this with a laptop also - it just throws away the shadow and highlight details of the image. Not good!

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EOSHD Pro Color for Sony cameras EOSHD Pro LOG for Sony CamerasEOSHD C-LOG and Film Profiles for All Canon DSLRs

That sounds similar yes, which is a bit concerning as it's unlikely to get a fix! 😐

 

They might have been recoverable in that case because the dynamic range was so low in that shot. Unfortunately with mine, they're completely gone. Nothing to recover!

 

Here's a picture, with some levels adjustments to show it up more clearly. Left is the internal camera recording, right is the ninja. So much lost shadow detail! 278789465_ninjav.thumb.jpg.70d024a647b76bb006c1d499607784fd.jpg

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I used the X-T2 with a Video Assist 4K not long after it was released, and I'm not sure if firmware updates changed things, but this is how it worked: the in camera recordings were indeed full range, but HDMI was remapped to video range, so nothing was really lost, but precision (220 luminance levels instead of 256). F-Log over HDMI was a different beast, it went up to 109% RGB, so even though it looked like it clipped highlights, it did not, and in Resolve I could easily recover that part of the image.

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3 hours ago, Matt Perks said:

That sounds similar yes, which is a bit concerning as it's unlikely to get a fix! 😐

 

They might have been recoverable in that case because the dynamic range was so low in that shot. Unfortunately with mine, they're completely gone. Nothing to recover!

 

Here's a picture, with some levels adjustments to show it up more clearly. Left is the internal camera recording, right is the ninja. So much lost shadow detail! 278789465_ninjav.thumb.jpg.70d024a647b76bb006c1d499607784fd.jpg

That's not good, please send these detailed info and pictures to Atomos so they could investigate.

@DBounce Could you test this when your Ninja V arrive?

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I've tried everything I know of to recover the lost detail but I really think that it's been clipped out of existence. Here's the Ninja file: https://drive.google.com/file/d/1C1NxTfwSi-miqkEt16GLNUYIBdINEGD4/view?usp=sharing

The detail lost is what's shown in the picture above, and as you can see the clip is way too contrasty and it's butchered the Fuji's otherwise pleasing colours and as far as I know there's nothing I can do to change that.

Hopefully I've just missed something! Take a look at the sample clip above to see if you can recover both the highlights and the shadows so that it looks somewhat like this:

 

130508467_01-FujiXT-2-h.264recording(straightfromcamera).thumb.jpg.8c37bd221a0fd88226030082db856d74.jpg

Rather than this:

213809205_02-NinjaVrecording-factorydefaults-DNxHR.thumb.jpg.5cbe6e5ffdf468995292e3a993fcfb9d.jpg

 

I can't use a LUT either, because it just clips the out of range data to black! Note that for this the camera was set to F-Log, which is why the shadow detail has become more visible. Unfortunately both the highlights (which in this case are mapped to 0) and shadow areas are still clipped (the original F-Log view is below - again, more shadow detail and highlight detail).

 

517620999_04-NinjaV-F-LogwithLut.thumb.jpg.8bcf44279d7c7cb278504d035fa1df1a.jpg

1505032618_05-OriginalXT-2h.264recordinginF-Log-nohighlightinfolost.thumb.jpg.6a3ac5b6ccd35130ce06d3dcf3301859.jpg

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Insight from Thomas Smet over at Dvxuser:

Quote

This has been an issue ever since we have had monitors and external recorders and Atomos absolutely refuses to do anything about it. I have emailed them, called them, others have begged on forums and Atomos doesn't believe its an issue so they will not do anything with it. We have been asking since the Ninja 2 and the response is always dancing around the issue and never really answering why they will not address it.

Thank goodness Panasonic has enough brains to allow users to select if they want 16-235 or 0-255 for the HDMI output but alas it doesn't work when shooting v-log and the camera is forced to use 0-255 which makes external recording not correct.

I honestly don't know how/why so many in the industry ignore this. Almost every review of external recorders I have ever watched on YouTube incorrectly thinks the recorder or ProRes just create darker video. The utter lack of understanding of this issue and the rabid spread of misinformation out there is enough to make me curl up into a fetal position in the corner of a dark room and cry myself to sleep.

Yes there are solutions in post and I have created my own lut and FCPX effect to deal with this but that still doesn't help how the image looks on the monitor while shooting. I know this because again thanks to Panasonic I can switch my camera back and forth between 16-235 and 0-255 and see how crushed the video looks on the monitor when using 0-255. This can lead to exposing the image incorrectly and attempting to over compensate for the added contrast and crushed dynamic range. While its a life saver to have solutions in post in 2018 we shouldn't have to deal with this issue anymore. Since the vast majority of external recorder users out there likely use a camera stuck at 0-255 Atomos needs to get their act together and add in a feature to correct the signal on input to the device.

 

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Just got a call from Atomos... Seems this is the first they have heard of this issue. In any case the tech I spoke with recommended that a support ticket be entered so that they can look into the matter. I would suggest anyone that is thinking about purchasing, or who may already purchased any Atomos recorders put in a ticket with the title "0-255 color space displayed incorrectly"

Perhaps if enough people hammer them they will finally look into fixing this issue? Here is a link to Atomos Support.

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I have a Ninja Inferno but I did not notice the issue, granted I have not used Vlog or compared the video from the Inferno to the SD card internal recording. Will also try this. What I have seen though is that there's more noise on the footages on the Inferno compared to what I'm seeing on the lcd..

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21 minutes ago, TurboRat said:

I have a Ninja Inferno but I did not notice the issue, granted I have not used Vlog or compared the video from the Inferno to the SD card internal recording. Will also try this. What I have seen though is that there's more noise on the footages on the Inferno compared to what I'm seeing on the lcd..

I believe the GH5 series can send in 16-235 color space, but automatically switches to 0-255 when sending VLogL to the HDMI port. So the problem would only occur when using log.

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I've been doing more testing and have narrowed it down to problems with DNxHR. When recording in ProRes, any values outside of 16-235 aren't displayed on the Ninja's screen, but are indeed saved in the recording, so behave just like in-camera recordings so no detail is lost as it can all be recovered. When recording in DNxHR however, values outside of 16-235 are lost resulting in heavy clipping. I'm not sure why this is the case - whether it's a bug, or whether DNxHR doesn't actually support 0-255 ranges or something, but they need to provide a fix of some kind, even if that's a 'remap to 16-235' setting for full range inputs.

So if you use ProRes, you're fine, if you use DNxHR and your camera can't remap to 16-235 by itself (or if you use Log) you're out of luck until Atomos fixes it (or 'if' they fix it).

There IS still a serious problem with LUTs however. No matter what, values above 235 are rendered as black, irrespective of ProRes or DNxHR, 8bit or 10bit. This is annoying for monitoring, as whites are now pure black which is distracting, but it also means you can't bake in LUTs, which is a feature I was looking forward to.

Below is a LOG recording with an almost blank LUT applied. As you can see, the highlights, which were lost as this was a DNxHR recording anyway, are just mapped to black. This is a problem even if your camera supports a limited output (16-235) as any sharpening artifacts that push past 235 are shown as black pixels. Basically this makes baked-in luts impossible, and LUT monitoring distracting. This definitely seems like a bug that they'll be able to fix however, so we'll see what they say. I've been in touch with support but have yet to hear back. Definitely try your own tests too so we can eliminate any other possible causes.

126958281_04-NinjaV-F-LogwithLut.thumb.jpg.dbb2346fc4fff39c65caf08f17f48e88.jpg

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23 minutes ago, androidlad said:

Another example showing the discrepancy between internal log recording and Ninja V recording, pretty drastic!

Maybe drastic is not the right word, that's a standard data levels vs video levels difference. If you put an original S-Log3 file into Resolve and set it to video levels manually, it will look exactly the same as the Ninja V file, which is automatically interpreted as video range.

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More user reported problems with Ninja V:

Quote

The Ninja-V was NOT behaving as expected; it still needs some special treatment when used with the Fuji X-T3. E.g: if you end a recording via the camera, the Ninja will flash black and the kangaroo icon appears; after that, most of the time, the Ninja will stutter and you will have to remove and plugin the HDMI. Nothing that a firmware update can't fix i guess.

 

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