Is 22.3MP the magic number for 1080 video from Canon?

[Andrew Reid]

16 hours ago, kidzrevil said:

@Andrew Reid the 5DS has a LOT of line skipping to get to that 2 megapixel 1080p image. Im not sure I’ve seen or heard anything good come out of that camera especially in comparison to canon’s other dslr

Check the DPReview studio chart 5DS vs 5D3

Slightly finer detail

Then check it against the rest of the Canons... thrashes them all. 7D II, 80D, 1D X II, the lot.

https://***URL removed***/reviews/canon-eos-5ds-sr/7

Also check the 42MP A7R II 1080p (pixel binned) vs 24MP Sony A9 1080p (full sensor readout) - something weird going on there as A7R II looks better.

[Don Kotlos]

Are you sure the A9 doing full sensor readout for 1080p? I thought the only Sony camera that do that are A7s*.

A7rII had a great FF 1080p mode, really close to A7s*. Real shame the A7rIII does not have as good HD in normal rates, but at least it does HD HFR much better. 

If I had the choice between full sensor readout 1080p and 4K with the same bitrate I would most often choose the 1080p. For example the 1080p 200mbps intra from GH5/s is just perfect. 

 

[Mokara]

On ‎2018‎-‎05‎-‎26 at 10:29 PM, kye said:

I have a theory about why Canon video quality is typically bad, and which models may be better than others.

We know from Magic Lantern that Canon uses every third pixel across the sensor to get 1920 x 1080.  The problem is that for most of their cameras there aren't quite enough pixels.

For my 18MP 700D, which is 5184x3456 that means the 3x3 resolution is 1728x1152 which cropped to 16:9 is 1728x972.  This then needs to be upscaled 111.11% to get 1920.  
We all know that upscaling video is not a nice thing to do, so despite Canon probably applying sharpening before compressing it, the recipe of RAW video -> upscaled -> processed -> compressed isn't a recipe for success!  
I suspect the combination of upscaling combined with the heavy ~56Mbps compression is the culprit as upscaling tends to soften detail and compression tends to crunch things that aren't sharp.  We know that sharp images can still survive a 50Mbps codec, and my ML RAW experiments seem to indicate that 1728x1152 isn't fundamentally terrible if treated nicely.

This leads me to question what the right recipe is.
If we start with 1920 and work backwards, we get 1920*3 = 5760.  This is how wide the sensor has to be for a 3x3 reduction to not need upscaling.  If the sensor is 3:2 then we need 5760x3840 which is 22.21MP.

Therefore, my theory is that all the Canon cameras with resolutions above 22.3MP should have superior 1080p quality.

According to this comparison table this would mean that the 5DIII, 5D4, 5DS, 6DII, 77D, 80D, 750D, 760D, 800D, 2000D, 200D, M3, M5, M6, M50 and M100 are the potential winners.

Does people's experience of these cameras back this up?

Of course, if any of the <22.3MP cameras took a higher resolution reading of the sensor and downscaled it then they would produce a nice 1080 image, but I don't know if any Canon DSLRs work in this way?

You are forgetting that individual pixels have a particular color, so information is lost during debeyering. To counter that you need more than 1920 lines of recorded information to reconstitute true 1920p (something like 2700p).

The basic problem is that the processors in older Canon cameras don't have the bandwidth to handle the amount of information necessary to reconstitute true 1920p, that is why they make those compromises, and it is the reason why Canon cameras generally produce softer images. Having a wider sensor will not change that.

[kidzrevil]

2 hours ago, Andrew Reid said:

Check the DPReview studio chart 5DS vs 5D3

Slightly finer detail

Then check it against the rest of the Canons... thrashes them all. 7D II, 80D, 1D X II, the lot.

https://***URL removed***/reviews/canon-eos-5ds-sr/7

Also check the 42MP A7R II 1080p (pixel binned) vs 24MP Sony A9 1080p (full sensor readout) - something weird going on there as A7R II looks better.

Oops I don’t think I said that correctly. Im thinking in comparison to Magic Lantern Raw. All stock canon’s are ridiculously soft but Canon raw as you know is a whole other animal. I wouldn’t know for sure without side by side testing but that doesn’t come close to Canon 5d raw at 1080, its good but there’s better

[kye]

14 hours ago, Mokara said:

You are forgetting that individual pixels have a particular color, so information is lost during debeyering. To counter that you need more than 1920 lines of recorded information to reconstitute true 1920p (something like 2700p).

The basic problem is that the processors in older Canon cameras don't have the bandwidth to handle the amount of information necessary to reconstitute true 1920p, that is why they make those compromises, and it is the reason why Canon cameras generally produce softer images. Having a wider sensor will not change that.

So, are you saying that the 18MP sensor is actually only 18 million photo sites?  ie, for two of the colours it only has 4.5 million pixels and the other has 9 million pixels?

If so, then how does that fit in with the 3x3 pixel binning?  and what about the chroma subsampling (I think it's 422 or 420 anyway) so maybe it would be enough pixels for 422 or 420?

I think I'm right in saying that 2x2 binning would be enough for full 1080 4:4:4, but 3x3 wouldn't be, but who knows - this stuff is quite confusing  

[kye]

Addendum: even if you're right, why does ML RAW processed and encoded into H264 via Resolve look so much better than Canon encoding H264 in camera?  This means that the sensor can at least read out fast enough, so maybe it's the DIGIC processor...

If this a limitation in the DIGIC processor then why doesn't the 700D with DIGIC 5 have drastically better video than the 600D/60D/5dmkII which have the DIGIC 4 when "Canon claims the new DIGIC 5 processor is six times faster than the DIGIC 4 processor" (from wikipedia).  

The DIGIC 5+ in the 5DmkIII and 70D "is an enhancement to the DIGIC 5 and DIGIC 4. The performance is said to be 17x the performance of the DIGIC 4" (almost three times the power of the DIGIC 5)

The DIGIC 6 appears to be almost a doubling in processing power, although who knows why it would be slower than the DIGIC 5+ but anyway.  "Further advancements attributed to DIGIC 6 can be experienced in movie mode, which records in MP4 format and doubles the frame-rate to 60 fps at 1080p".  

And if those doesn't have enough horsepower then why not go all the way to the M50 with the DIGIC 8 (surely the 8 would be better - it can process 4K at 25fps!) and get decent 1080 performance?

I get that Canon want to protect their more expensive cameras, but regardless of how much money I pay I don't want a physically larger camera.  And the XC10 can process UHD at 30fps compressing it to 305Mbit files, and that's in a smaller form-factor too.

[kye]

15 hours ago, Andrew Reid said:

Check the DPReview studio chart 5DS vs 5D3

Slightly finer detail

Then check it against the rest of the Canons... thrashes them all. 7D II, 80D, 1D X II, the lot.

https://***URL removed***/reviews/canon-eos-5ds-sr/7

Also check the 42MP A7R II 1080p (pixel binned) vs 24MP Sony A9 1080p (full sensor readout) - something weird going on there as A7R II looks better.

Sorry Andrew - somehow I didn't see your post.  

Thanks for the link, I didn't realise that they included video compare function now, that's very useful.

If only the XC10 had interchangeable lenses - even in 1080 it still has the edge over the 5DS.

[Mokara]

10 hours ago, kye said:

Addendum: even if you're right, why does ML RAW processed and encoded into H264 via Resolve look so much better than Canon encoding H264 in camera?  This means that the sensor can at least read out fast enough, so maybe it's the DIGIC processor...

If this a limitation in the DIGIC processor then why doesn't the 700D with DIGIC 5 have drastically better video than the 600D/60D/5dmkII which have the DIGIC 4 when "Canon claims the new DIGIC 5 processor is six times faster than the DIGIC 4 processor" (from wikipedia).  

The DIGIC 5+ in the 5DmkIII and 70D "is an enhancement to the DIGIC 5 and DIGIC 4. The performance is said to be 17x the performance of the DIGIC 4" (almost three times the power of the DIGIC 5)

The DIGIC 6 appears to be almost a doubling in processing power, although who knows why it would be slower than the DIGIC 5+ but anyway.  "Further advancements attributed to DIGIC 6 can be experienced in movie mode, which records in MP4 format and doubles the frame-rate to 60 fps at 1080p".  

And if those doesn't have enough horsepower then why not go all the way to the M50 with the DIGIC 8 (surely the 8 would be better - it can process 4K at 25fps!) and get decent 1080 performance?

I get that Canon want to protect their more expensive cameras, but regardless of how much money I pay I don't want a physically larger camera.  And the XC10 can process UHD at 30fps compressing it to 305Mbit files, and that's in a smaller form-factor too.

Encoding is done by a dedicate block in the CPU, and that is pretty much carried over through different generations of processors with some tweaks along the way, such as upping frame rate or bit rate slightly. The increase in processing power primarily affects other operations. That is why you see similar video IQ from cameras across generations. Because it is still bound by the limitations of the block design, primarily heat generation, they likely have to make a lot of compromises that you don't need to make in post (basically dumping information in the name of thermal efficiency). That is why you get better IQ with ML RAW and processing it in post. It is not the processing power of the camera's CPU that is important, it is the GPU inside, and you can get an indication of what that is from the video specs of individual products.

The Digic 8 may have a 4K hardware encoder in it, but the 1080p block is likely the same or very similar to those on earlier processors and consequently will have the similar limitations. Btw, Digic 7 (which is the stills version of the DV5 inside the XC10) actually has a more capable 4K variant in it, but it just cant be used in conventional cameras because of the amount of heat it generates. 4K in Digic 8 is a crippled version of the block in Digic 7 so as to allow it to operate within the thermal envelope of typical stills cameras. To shoot hardware encoded 4K with a 7/DV5 you need a cooling solution, such as a fan, which is not practical in stills/hybrid cameras. Hence no hardware 4K in Canon consumer products, outside of MJPEG (which uses the processor for encoding rather than the GPU).

Other manufacturers can get away with proper 4K hardware encoding and high bit rate FHD because their processors are much more thermally efficient than the Digic processors used by Canon. This is the basic challenge Canon faces in bringing to us the sorts of video products we want. I know a lot of people go on about Canon doing this on purpose as deliberate market segmentation, but they are wrong. Canon does it because that is the only option available to them with the processor technology they have.

[kye]

Thanks @Mokara that makes total sense.

I realise I'm having the same conversation in multiple threads now but I guess I'm more concerned about the size rather than the form factor.  The XC10 has lovely image processing (1080 included), has a fan included, and is still a lot smaller than the smallest of the Cinema cameras.

Canon would absolutely kill it by taking a DSLR body (perhaps something like the 80D) and then:

• removing the mirror to make it mirrorless and using that space for a continuously variable ND filter
  this would allow a mode where you could set shutter speed and aperture and then by controlling the ND and the ISO it would manage exposure in all situations
• using a really nice sensor that did fast read-outs and had lots of DPAF points
  if they put in a high-speed buffer chip they could have very low RS too
• putting in both a DIGIC and a DV chip to enable full quality processing
  yes, this would mean the body would have to be a bit bigger and include a thermal solution, and hopefully would offer 4k60 and 1080p120
• adding a CFast card slot for high-bitrate files
  I realise this could be CF or high speed SD but I already own CFast cards for my XC10 and this is my fantasy so...
• adding an extra dial and one or two extra custom buttons
  the XC10 only has one dial and three custom buttons and they're not quite enough
• and while we're at it, include a crop mode for ~3x zoom but with the same image processing

This would create a camera that would be a high performance hybrid (as it should retain all the stills functionality too) and perhaps a new line.  This sounds like a big ask but the XC line was brand new, and was aiming at people that wanted video on the go with the ability to pull still images from that video, so in a way Canon already has a hybrid line.  

So then, if you're going to have a hybrid line then why not have a high-end model in that hybrid line?  Yes, charge for it.  But it doesn't have to be so large.

The logic makes sense because:

• It won't do video as well as the dedicated video cameras with heaps of buttons and SDI connections and all that pro stuff (if that stuff didn't matter then why were there other cameras in the range above the C100 mk I?)
• It doesn't do stills as well as the dedicated stills cameras like the 5DR or 1DXmkII

(or, I could put it another way - start with an iPhone and .....)

These cameras can be radically smaller.  I'm just suggesting the next logical step in convergence.  

[BTM_Pix]

I'm going to be radical here and say maybe you should consider the Sony AX700 camcorder as I think it ticks a lot of your boxes?

Built in variable ND, HLG (as well as SLOG 2&3), 250 fps in HD and their very, very smart new hybrid AF system amongst other things make it a brilliant shot grabber whilst having a bit more about it for more considered shooting as well. It can take XLRs via the smart shoe adapter if needed.

And nothing is more discreet for filming in public places without getting hassled than something that looks like a palmcorder.

You're more likely to elicit a response of "aww bless, look at him there with his old fashioned camcorder" than "whats that guy up to with all that gear?" to be honest

Its not a sexy solution but I honestly think it will get you where you want to be going with a lot less angst.

And not without decent quality either.

[kye]

13 minutes ago, BTM_Pix said:

I'm going to be radical here and say maybe you should consider the Sony AX700 camcorder as I think it ticks a lot of your boxes?

It does, I suspect almost as many as the XC10.  It was the interchangeable lenses to give me f2.8 on FF (or F4 in a pinch) that is missing, and then with that the AF system to match.

Beyond those things the XC10 is just great..  Getting half-decent 1080 on a Canon DSLR was a big compromise of many aspects to try and get the depth and separation that larger apertures give.

Thanks for trying though!

[BTM_Pix]

45 minutes ago, kye said:

It does, I suspect almost as many as the XC10.  It was the interchangeable lenses to give me f2.8 on FF (or F4 in a pinch) that is missing, and then with that the AF system to match.

Beyond those things the XC10 is just great..  Getting half-decent 1080 on a Canon DSLR was a big compromise of many aspects to try and get the depth and separation that larger apertures give.

Thanks for trying though!

Fair enough (though the new hybrid AF on that Sony is actually very effective).

I don't have an XC10 but my experience with other 1" cameras like RX100 or FZ2000 is that background separation isn't an issue if I have the space to achieve it with a longer focal length but not all situations afford that if you can't control the environment so its never guaranteed.

You can always go old school on your XC10 with an old 35mm spinning ground glass adapter but I think we've been there before and it was a bridge (camera) too far when it came to stealth