Dynamic range test - EOS R / X-T3 / Z7 / A7 III / GH5S / who has the best LOG?

[Andrew Reid]

On the Nikon Z7 how much difference does 10bit N-LOG make?

Is there a step up from the Canon EOS R when you record 10bit externally?

How does the Fuji X-T3 compare in F-LOG at 10bit internally?

All the questions and more I set out to answer here...

Read the full article

[leobauberger]

Awesome test, I was looking for this!
I have one question: when using an external recorder, due shooting into another codecs (dnx/prosres) the bitrate remains the same as the internal one?
Because these codecs are less compressed than h264/h265, therefore easy to edit, but what about quality wise?
Using a external recorder in eos r only changes the edit flow and record limits then?

[Andrew Reid]

You can learn more about ProRes from Apple's latest 2018 ProRes white paper https://www.apple.com/final-cut-pro/docs/Apple_ProRes_White_Paper.pdf

ProRes is variable bit-rate (VBR) but target bitrates are:

ProRes 422 HQ = 737 Mbit ALL-I in UHD 4K.

Standard ProRes 422 is 492 Mbit ALL-I

"As a variable bit rate (VBR) codec technology, ProRes uses fewer bits on simple frames that would not benefit from encoding at a higher data rate. All ProRes codecs are frame-independent (or “intra-frame”) codecs, meaning that each frame is encoded and decoded independently of any other frame. This technique provides the greatest editing performance and flexibility."

I used ProRes 422 HQ in the test to record Nikon Z7 N-LOG 4K.

I usually find ProRes 422 LT at 342 Mbit ALL-I saves space without any real noticeable loss in quality.

If shooting in 1080p the bitrates are a lot lower (220Mbit for ProRes 422 HQ).

[Deadcode]

EosR - A7 III - X-T3 - GH5s - Z7  (lifted) shadow noise at +2EV:

Thanks for doing this comparison!

[Andrew Reid]

Ah you found the Pink Floyd album Thanks, exactly the kind of grades I'd like to see from original file on Vimeo. Keep em coming!

(Click video title to go and download it)

I like the Kate Bush one!

Z7 has best Kate Bush! That's the N-LOG or Flat shot?

I think that one also brought the most out of the blacks too. Cooke lens clearly visible next to the Floyd LP.

[Deadcode]

9 minutes ago, Andrew Reid said:

Ah you found the Pink Floyd album Thanks, exactly the kind of grades I'd like to see from original file on Vimeo. Keep em coming!

(Click video title to go and download it)

I like the Kate Bush one!

Z7 has best Kate Bush! That's the N-LOG or Flat shot?

I think that one also brought the most out of the blacks too. Cooke lens clearly visible next to the Floyd LP.

On the sidebyside picture there is the Nikon FLAT. Nikon N-Log +2EV is actually missing from your comparison! The original N-Log is underexposed, i am unable to recover anything from the dark areas. 

[Andrew Reid]

Check out the lightbulb area in the +2ev shots as well. Also the synth control panel in the middle of the frame. The A7 III (S-LOG 2) has more dynamic range in that area of the image than the Z7 Flat profile does, so the shadows are not the whole story.

I will try a few more external recordings tomorrow, +2ev as well.

[tyger11]

Would the 4:2:0 internal vs 4:2:2 external with the X-T3 make any difference?

[Deadcode]

A7 III has the widest dynamic range, however the darkest parts of the image tends to shift magenta, as usual with Sony cameras

X-T3 seems like losing about 2/3 stop in the highlights and 1/3 in the shadows compared to A7 III, and the dark parts slightly shifts to green. I would redo this test with the original h265 file, because Resolve dont set the data levels correctly (at least Resolve 14), so if you created this comparison in resolve, maybe you missed the superwhites/blacks in the transcoding

EosR is impressive, it has same information in the shadows as the X-T3 but losing about a stop in the highlights

GH5 has the same highlight information as the X-T3, but losing about a stop in the shadows

The Z7 Flat has the most shadow detail but it losing more then 1,5 stops in the highlight compared to X-T3

Interesting to see how well the 8 bit low bitrate codec's hold's up against 10 bit high bitrate. The reason is probably the fully used dynamic range, in low DR + underexposed scene the difference would be much more visible after color correction.

Edit: in my first post in the shadow nosie comparison the correct camera order from left to right:

GH5 - A7 III - X-T3 - EosR - Z7, just like above

[Shirozina]

There is a basic error in the article regarding 8bit in video - it's not RGB it's YCbCr which means the tonal graduation is much more than 256 steps and the gamut is not 16million colours.  

[TurboRat]

6 hours ago, Deadcode said:

EosR - A7 III - X-T3 - GH5s - Z7  (lifted) shadow noise at +2EV:

Thanks for doing this comparison!

Why is the contrast higher on the GH5? bec of exposure?

[Danyyyel]

8 hours ago, Deadcode said:

On the sidebyside picture there is the Nikon FLAT. Nikon N-Log +2EV is actually missing from your comparison! The original N-Log is underexposed, i am unable to recover anything from the dark areas. 

If the Nikon Flat is that clean compared to the other logs in the shadows, it corroborate some test that showed that it was very close to log. You could clearly underexpose by one stop to preserve the highlight and come very close to the other logs. For the Nikon Z7 log it is exact contrary, I have not been able to download the high bitrate vimeo file for now, but we can clearly see from the highlight in the bulb that is clearly underexposed by at least 1 stop compared to the other log file. It would have been very nice to match the highlight of at least the Sony to see how much detail is left in the shadows.

[leobauberger]

8 hours ago, Andrew Reid said:

You can learn more about ProRes from Apple's latest 2018 ProRes white paper https://www.apple.com/final-cut-pro/docs/Apple_ProRes_White_Paper.pdf

ProRes is variable bit-rate (VBR) but target bitrates are:

ProRes 422 HQ = 737 Mbit ALL-I in UHD 4K.

Standard ProRes 422 is 492 Mbit ALL-I

"As a variable bit rate (VBR) codec technology, ProRes uses fewer bits on simple frames that would not benefit from encoding at a higher data rate. All ProRes codecs are frame-independent (or “intra-frame”) codecs, meaning that each frame is encoded and decoded independently of any other frame. This technique provides the greatest editing performance and flexibility."

I used ProRes 422 HQ in the test to record Nikon Z7 N-LOG 4K.

I usually find ProRes 422 LT at 342 Mbit ALL-I saves space without any real noticeable loss in quality.

If shooting in 1080p the bitrates are a lot lower (220Mbit for ProRes 422 HQ).

 Andrew thanks for this, but I'm new into external recorders area. I still didn't get if you can have a better overall visible bump in image or if it's marginal and in the ends what matters is the internal recording options (regarding only the eos r)

[androidlad]

Was in-camera noise reduction turned down completely for the test? For example, X-T3 has NR default at 0, but it can be set to -4.

[Higgs]

I'm not sure the test of 8bit vs 10bit for Rec.709 gamma is valid. We won't see greater dynamic range for 10bit video in 8bit jpeg screenshots unless we start pulling the exposure or apply some other correction to compress the dynamic range to be visible in 8bit jpegs and standard displays.

[Deadcode]

3 hours ago, TurboRat said:

Why is the contrast higher on the GH5? bec of exposure?

Black levels and exposure are roughly matched, contrast is more or less close to each other. Technically you compare noise levels and shadow detail here, the contrast difference does not matter. 

1 hour ago, Danyyyel said:

If the Nikon Flat is that clean compared to the other logs in the shadows, it corroborate some test that showed that it was very close to log. You could clearly underexpose by one stop to preserve the highlight and come very close to the other logs. For the Nikon Z7 log it is exact contrary, I have not been able to download the high bitrate vimeo file for now, but we can clearly see from the highlight in the bulb that is clearly underexposed by at least 1 stop compared to the other log file. It would have been very nice to match the highlight of at least the Sony to see how much detail is left in the shadows.

Probably there IS a difference between N-Log and Flat, just like with the Sonys. Cine 4 has 2 stops narrower dynamic range compared to SLOG2

I think middle grey should be exposed to the same level. If we expose for the highlights it's much harder match the shots in post.

[Oliver Daniel]

Personally I'm seeing a huge difference between 10 bit and 8bit. The implementation on certain cameras may need some questioning, however when implemented well it's night and day. 

The true value of 10 bit is when I'm pushing the files around in grading, 10 bit is usually much smoother, has much less artefacts and has more tonal variety. The image quality difference comes after grading. It's so apparent that I don't use 8bit that much anymore. 

There's more at play with this example (codecs, sensors), but 10 bit GH5 vs 8bit A6500 is no contest. The GH5 image pulls around nicely, looks smooth and thick, whereas the A6500 image will get easily blotchy, blocky and the colours are sometimes smeary.

Correcting white balance on the GH5 is easy, on the A6500 you might as well not bother. 

Dynamic range is better on the A6500, this is where I wish the GH5 would improve. 

[leobauberger]

Look, Carl from proav did an awesome test showing lot of stuff: 

It's a very good video overall IMO.

I wish they tested the 10 bit external in the EOS R/X-T3, because that's when I think bit deph can make a difference or not.
Maybe Andrew can do something similar to that?

[Andrew Reid]

Maybe I can

[Nikkor]

It would be cool if you could upload 16bit screengrab sample tifs instead of video files, it's much easier to download and to compare several files in PS. Thanks @Andrew Reid