Author Topic: Magic Lantern Cinema Camera - Dual ISO without aliasing & without quality loss!  (Read 21452 times)

theBilalFakhouri

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Original file in Google Drive: Download

Shot on 700D:
1504x640 in 3x3 and 1504x1920 in 1x3 downsized to 1504x640 (@ 23.976FPS 2.35:1).
I can shoot up to 1736x736 (1736x2214 in 1x3) 2.35:1 but this requires 80mb/s write speed in 1x3 Binning mode so I reduced the resolution to get more recording times (with sd_uhs).

Aliasing:
There is a little bit of aliasing in some cases (not noticeable) but it's a lot better than normal video in 3x3 without Dual ISO! we can say No aliasing.

This means in our Cameras we have now:
-RAW Video without aliasing and Moire!
-Entire dynamic range which is around 14 Stops!
-No quality loss when using Dual ISO!
-Less noise Better shadows in low light!
-Cinema Camera! :D

The problems:
-Very stretched LiveView
-This is require high write speeds (80mb/s in 1736x736 @ 23.976fps 14-bit lossless for 700D).
Solution:
The problems are the write speed now about 80mb/s in 14-bit lossless (1736x736) so no continuous recording but this is the small problem and with some more tries to get higher SD writes speed and using Analog gain to get 10-bit lossless working in increased resolution will become not a big deal.

Annoying one: LiveView is very stretched! you can use ML Framing instead which is slow unfortunately.

How can you try it?
Just wait for the new crop_rec to be ported in other cameras and maybe this is easy, Look at bleeding-edge testing.

Bleeding-edge testing:
700D: Here
6D:    Here
5D3:  Here
EOS M: Here

More Details:
https://www.magiclantern.fm/forum/index.php?topic=19300.msg206040#msg206040
https://www.magiclantern.fm/forum/index.php?topic=19300.msg206086#msg206086
https://www.magiclantern.fm/forum/index.php?topic=19300.msg206133#msg206133
700D 1.1.5 | no more ISOless LV err 8

squig

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The +5EV 1x3 dual ISO shot looks amazing. Dude, where's my noise?

Am I imagining things or is the rolling shutter reduced too?

A ML anamorphic stretch should fix the LiveView problem. 

2K 1.5x anamorphic scope (1413x2574) is a slightly lower data rate than 1736x2214 1x3 @80MB/s. 2K 14 stop 5D Mk3 anyone? :D

bouncyball

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Amazing! You made me respecting DUAL ISO mode for video ;) (really hated this before).

Have to try that out.

Regards
BB

togg

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This is incredible, thanks so much, also for opening the discussion. It will be easier to follow development here.

Now I'll have to study how to actually post process dual iso, I have no clue if the info are baked into exported dng and work nicelly in Resolve or if you need to export ProRes mmm

IDA_ML

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Now I'll have to study how to actually post process dual iso, I have no clue if the info are baked into exported dng and work nicelly in Resolve or if you need to export ProRes mmm

Nothing to study here.  Just use the latest version of MLV App.  It handles Dual ISO files really nicely and exports to ProRes too. 

Danne

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Bilal, a1ex. Epicness...

Markus

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Can you try this on 5D3?

theBilalFakhouri

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@squig
Yeah the noise has packed its bags when it saw 1x3 beside dual iso :P . Even without dual iso there is an good enhancement. More tests in the future.

Is the rolling shutter has increased? I am not really sure it shows in 1x3 16.2 µ/line (35.9 ms (86%) at 1736x2214) instead in 3x3 16.5 µ/line (19.1 ms (46%) at 1736x1160). Maybe after stretching down the vertical in 1x3 this affect the rolling shutter I am not sure about this. What do you think @a1ex? I am will make test for rolling shutter in the future.

ML anamorphic stretch can help but in 1x3 the LiveView only showing top of the frame and you can't see the bottom part.

@bouncyball
Yes the aliasing and moire and also the quality loss was very annoying. Now the write speed and stretched LiveView is the new problem we will hate :D

@togg
I just can say Magic Lantern has converted our cheap old toys to really High End Cinema Cameras! @Canon did you know about this before? :P

@Danne
Thank you! I hope this will not stop here until we get normal LiveView (it's really complex! we can find out by comparing between mv1080 and mv720) and also higher write speeds(This will speed up the progress if we work together and try diffrenet values ). I will not buy a new camera if this happened.  :D

@Markus
I don't have 5D3 unfortunately and the new crop_rec maybe doesn't fully support yet 5D3 not sure. Just wait to be supported for all other D5 cameras and you can try it with your hands :D .
700D 1.1.5 | no more ISOless LV err 8

togg

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@Markus
I don't have 5D3 unfortunately and the new crop_rec maybe doesn't fully support yet 5D3 not sure. Just wait to be supported for all other D5 cameras and you can try it with your hands :D .

I'm not technical savy, not in a hurry either, just curious to know if there're important camera limitations, maybe someone else has got the scale of this already?

Nothing to study here.  Just use the latest version of MLV App.  It handles Dual ISO files really nicely and exports to ProRes too.


mmm thing is I don't want to export to ProRes, I want to export lossless dng to bring them to Resolve. I'm unsure if dualiso info are processed into a normal file when "extracting" dngs. I don't have my camera to try it out!

Levas

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For the 5d3, 3x1 mode has probably only benefit for dual iso.
The 5d3 already does vertical pixelbinning instead of lineskipping.
So a plain, straight from Canon factory 5d3 already has the aliasing and noise benefits 3x1 mode gives to lineskipping camera's.


 

12georgiadis

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For the 5d3, 3x1 mode has probably only benefit for dual iso.
The 5d3 already does vertical pixelbinning instead of lineskipping.
So a plain, straight from Canon factory 5d3 already has the aliasing and noise benefits 3x1 mode gives to lineskipping camera's.
Levas, you mentionned that 3X1 or 1X3 (correct me) triples the bitrate. But is it the case with 5DmkIII ? It seems that the bitrate is the same as the other cameras for the same resolutions...

Levas

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The 5d3 does the binning in hardware, if I'm correct, this is done on CMOS sensor level.
So the raw video stream is already normal sized, so normal bitrates.
Alex posted this long ago about pixel binning patterns, interesting read about how the sensor is read in Canon DSLR's:
https://www.magiclantern.fm/forum/index.php?topic=16516.msg160831#msg160831



 

12georgiadis

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thank you levas

Levas

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About the binning, it could be the case that more Canon camera's can do vertical pixelbinnig by default, but that Canon has not enabled it in firmware...
I doubt it, because it would possible be already found by some one messing with the registers.
But hey, we're talking about Canon here, so I wouldn't be surprised  :P

togg

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The 5d3 does the binning in hardware, if I'm correct, this is done on CMOS sensor level.
So the raw video stream is already normal sized, so normal bitrates.

does this mean that it will be harder/impossible to make the same trick work? Because the dual iso usage would be very important by itself I feel.

Levas

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The 5d3 can do the same trick, all canons can do 3x1 1x3 mode.
3x1 1x3  mode is actually a mix between normal view(3x3) and 5xzoom mode (1x1)
But for 5d3 this 3x1 1x3 mode is only interesting for dual iso, the other benefits are already there for 5d3.

Edit: Sorry theBilalFakhouri, used to horizontal x vertical...not vice versa  :P

theBilalFakhouri

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 ::)
@Levas
3x1 and 1x3 Binning mods is completely different things :P we have them both in new crop_rec. Can you please re-edit your posts to 1x3 for not making the users confused.
700D 1.1.5 | no more ISOless LV err 8

togg

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The 5d3 can do the same trick, all canons can do 3x1 mode.
3x1 mode is actually a mix between normal view(3x3) and 5xzoom mode (1x1)
But for 5d3 this 3x1 mode is only interesting for dual iso, the other benefits are already there for 5d3.

Ok nice, can't wait for clean dual iso onestly!

Karim

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Shot on 700D:
1504x640 in 3x3 and 1504x1920 in 1x3 downsized to 1504x640 (@ 23.976FPS 2.35:1).
I can shoot up to 1736x736 (1736x2214 in 1x3) 2.35:1 but this requires 80mb/s write speed in 1x3 Binning mode


The problems:
-Very stretched LiveView


I just checked your video the dynamic range is so impressive and aliasing is almost gone!

I want to clarify some confusing things
what is 3x3 and 1x3 exactly and what's the difference?
I know about the line skipping thing the sensor does to fit a video is that something related?

why you downsize your videos? after all I cant notice visual difference in the video but it's more technical of course

I own a 6D I think your options doesn't available for my crop_rec but I want to understand how things goes on
also dual iso +mlvapp work with 14 bit only any lower Iget a final glitchy video does it tha same on 700D?


theBilalFakhouri

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@Karim

Yes 3x3 and 1x3 is about line skipping in sensor.

5D3 can do 3x3 column binning and line binning otherwise the other cameras like 700D it's doing column binning but line skipping so using 1x3 (Bin 3 columns and read every line) instead of skipping lines (skipping lines causing aliasing and moire patterns) now we get the Actual height of sensor 1736x738 in 3x3 becomes 1736x2214 (stretched height) by scaling down the vertical to 738 in post this process look like Binning lines in 5D3 directly in camera but we did it in the post so now we have got clean image without aliasing and moire and with less noise.

More details about Pixel Binning.

Doing Dual ISO after the Binning process it will show a lot of artifacts and aliasing here will come the big benefit of 1x3 mode applying Dual ISO in full sensor height (using more pixels for dual iso) then stretching it down to the correct aspect ratio. In this way the details will be restored with less aliasing and less noise too.

In MLVApp there are no problems when using Dual ISO with 14/12/11-8 bit lossless and 14-bit uncompressed. But last time I got glitchy footage when I used 10-bit uncompressed with Dual ISO I will make more tests to make sure what's happening. If you have a problem with MLVApp you can explain what's happening and give some samples and screenshots in MLVApp thread to get some help ;D.

And you can speak Arabic you are from Egypt? I am from Syria nice to meet you here in the forum :D

أهلاا و سهلاا
700D 1.1.5 | no more ISOless LV err 8

bouncyball

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also dual iso +mlvapp work with 14 bit only any lower Iget a final glitchy video
As I remember 6D lossless needed some special approach (black level correction for every channel, @a1ex: is that still an issue?) It is not implemented into mlv app. Can you upload some MLVs to test?

Levas

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The first days of lossless on the 6d needed indeed a black level fix for all channels.
But this has been solved by Alex, the 6d lossless is now the same as other cams.

I can conform that MLVAPP works for 14 bit dual iso files from the 6d, used it with the lunar eclipse a few months ago.
Never tried any other then 14 uncompressed and 14 bit lossless for dual iso video.
Will try to test today what happens in MLVAPP when using dual iso in 12 bit lossless and 12 bit uncompressed etc.
 



Levas

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Not tested anything yet, but to be sure, dual iso should work with lower lossless bit like 12 bit lossless, right ?

Levas

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On the 6d, dual-iso 12 bit lossless and 12 bit uncompressed are working normal in MLVapp over here.
@Karim, are you sure you didn't accidentally enabled other options in MLVapp, like the option to fix 'pattern noise', right below dual-iso settings in MLVapp ?
Pattern noise option really messes up my dual iso video.

Levas

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Made a 1x3 preset in crop_rec module for 6d users to play with.

https://www.magiclantern.fm/forum/index.php?topic=15088.msg206420#msg206420