Author Topic: Magic Lantern Cinema Camera - Dual ISO without aliasing & without quality loss!  (Read 20392 times)

Walter Schulz

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Lines(rows) x Columns. An array.
Native Canon full HD (1920x1080) in 5D3 is processed by 3x3 binning. Means: The data contents of 3x3 pixels are processed into 1 pixel output.

1x3 binning is done in most other Canon DSLRs: 3 pixels in a line are binned but lines are treated not this way. Only every 3rd line is processed. 2 out of 3 lines are not processed at all, they are "skipped". Visible aliasing effects often occur. Canon fights this by some data manipulation with disputable results.

With ML RAW/MLV it is possible to use one or the other.
And there is a third option 1:1 (or 1x1) where no binning and skipping takes place. But this requires using a reduced sensor area = Crop mode.
Photogs and videographers: Assist in proof reading upcoming in-camera help!. Your input is wanted and needed!

LoO93

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@Walter Schultz Thank you very much for the clear and simple explanation.

berechiah

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Wow thanks you so much

That is the best and most understandable way I heard it explained

I read tons of times every where else but still was no clearer in understanding what it ment

Thanks for taking the time to explain

Much appreciated

Danne

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Eosm now working without restrictions regarding 1x3 binning mode:
https://www.magiclantern.fm/forum/index.php?topic=9741.msg210369#msg210369

IDA_ML

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Danne,

Bilal and you seem to be creating history here !!!  I knew, it was possible, I knew it !!!  This new 1x3 mode makes the problematic 3x1 modes redundant, right?

Danne

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If you know a way to record around 100mb/s we´re all set  8)

theBilalFakhouri

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 8) 8)
700D 1.1.5 | no more ISOless LV err 8

IDA_ML

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If you know a way to record around 100mb/s we´re all set  8)

Yes, I know a very efficient way that will work 100%.  It's the EOS 7D.  It can write at 90 MB/s as it is, without even overclocking.  If all this new stuff is implemented into the 7D, indeed we are all set.  ;)

Danne

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Just set up a sourcetree and start testing stuff. One step at the time...

ibrahim

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What is the highest resolution you guys have been able to record with dual iso on 5d3 12-bit lossless 2.35:1 or 16:9  with the experimental builds?
Does it also involve x5 crop mode? and at what binning for dual iso? Thanks in advance.
Canon 5D Mark IIIs & Canon 600d | Ronin-M | Rokinon 35mm T1.5 Cine AS UMC | Samyang 85mm T1.5 UMC AS Cine VDSLR II   | Canon EF 24-105mm f/4L IS USM | Canon EF 50mm f/1.8 II | etc
Dual sound system: Tascam DR-60d MKII | Audio Technica AT899 | Sennheiser MKE 600

70MM13

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I have been resisting the pull of dual iso since day 1 because I have always been happy with the results of gain reduction at iso 200 and the benefit of not dealing with all the issues surrounding dual iso...

But, after a shot yesterday that just didn't cut it, I decided to try again today with dual, and it won!

Now, to be totally clear, in this comparison, the iso200 version was without gain reduction (i was too lazy to change magic lantern versions) but in practice, canon 200 (only 200) is _almost_ as good as gain reduction, so it could have been a little better, plus it would be at 3072 instead of 1920, but even so, dual would win, clearly.

I lifted the shadows only to the point where the single iso was still marginally acceptable, but the dual version could go MUCH higher with no problems.  It's the champion!

So, I am going to start using this today...  I only hope it works reliably, and at 24 fps without too much nonsense.

Keep up the amazing work, I'm a believer!










Dmytro_ua

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70MM13

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unfortunately i didn't think about it while shooting.

different exposure levels due to iso 200/100, and since i was using a manual aperture lens, it was quick and easy to just change the aperture to adjust.

sorry about that!

70MM13

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hey those in the know...

i just accidentally took a photo with dual iso enabled (i didn't think it would affect photo mode when set in video mode) and it is a nature shot that cannot be retaken.

i am so far unable to correct it (using barracudaGUI) because presumably it can't handle the 1*3 binning...

can anyone help me sort this out?  I'd hate to lose the shot.

thanks in advance!

dfort

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Have you processed it through cr2hdr or one of the apps that can handle dual iso? If you are still having problems upload your file so we can take a look at it.
5D3.* 7D.206 700D.115 EOSM.203 EOSM2.103 M50.102

70MM13

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yes, barracuda is a frontend for cr2hdr.  no joy.

is there a way to convert it to a single frame mlv so i can just load it into mlvapp?

i'd like to try to resolve it first without uploading if possible because it's a full frame cr2 which is a big file...

70MM13

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I sorted it out...

for some reason, I had to place cr2hdr.exe in the same folder as the images, even though I was running barracudaGUI from another folder, and then suddenly it worked correctly.

I'm just thankful that I was able to salvage the image, and it turned out beautifully!

thanks for the offer to help.  I appreciate it!

70MM13

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I did a serious torture test to compare the results of gain reduction vs your magical dual iso...

The scene was extremely dark, with a direct harsh light as the subject, filled with shadow detail.

Even though the gain reduction version was shot at 3072, thanks to your magic, the dual iso version looks just as good.  The upscaling works beautifully!

FYI, I also shot it in stock canon iso 200, and that was not even worth mentioning.

I'm looking forward to trying this in my next video, I just hope it can work smoothly without any surprise stops.

fingers crossed!

keep up the great work!

addendum:

I am running into a brick wall after a few hundred frames, with a fresh fast CF card.  I get continuous at 3072px normally with iso 109, but obviously this mode requires more bandwidth.  Is there any possibility of card spanning with the sd card to get that little bit extra to at least get a less restricted recording time, if not continuous?

I really like what I'm seeing, but 300 frames just isn't enough...


vstrglv

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Uploaded a new build for testing:
https://bitbucket.org/Dannephoto/magic-lantern/downloads/crop_rec_4k_mlv_snd_1x3_10bit.5D3113_presets.zip
Danne, thanks for your builds.
What is the latest build for dual iso "crop_rec_4k_mlv_snd_1x3_10bit.12bit.5D3113?
Canon 5D3,1.1.3 CF-SanDisk Extreme PRO,160MB/s, 256GB, SD-SanDisk Extreme, 90MB/s, 64GB.

Danne

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Not much happened for the 5d3 lately. You could test this build:
https://bitbucket.org/Dannephoto/magic-lantern/downloads/crop_rec_4k_mlv_snd_isogain_1x3_presets_2019Feb08.5D3113.zip

New is the 1x3 binning recordings will be upsampled in Mlv App instead of downsampled so now files comes out 4k or 5k depending on what preset you choose.

70MM13

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i just took it for a spin, and the 1*3 crop mode instantly locks up the camera, requiring a battery pull to revive again, consistently.

the 17fps preset works though.

the build from january works fine for me.

any suggestions?

Danne

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Took it off for now. Will take a look in a few days.
Thanks.

70MM13

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12 bit test...


edit:

deleted.  i fumbled around and eventually the flickering was resolved.  it was definitely some random confluence of factors.  it's rock solid now.

70MM13

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12 bit is working really beautifully in my 5d3 testing!

I just finished a wide range of extreme scenarios, and everything is looking excellent.

This example image is almost misrepresentative of the extreme conditions, it looks so good...

Exposed for the bulb, zero clipping, and falling off to near darkness.  so dark that the camera display is basically black except for the bulb.

The curve I made for it in mlvapp linear mode is vertical.

Chroma noise removed with neat video.

That's all that was done outside of mlvapp.

You guys should be extremely proud of what you are enabling with this magic :)

I'll be shooting a film noir video using this, and it's so great to plan shots to take advantage of this!



timbytheriver

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@Danne / @70MM13

What's the correct setup/preset to select this dual_iso 1x3 mode being discussed here – on 5D3 1.2.3 ?

I'm using @Danne's build from 15Feb2019. Is this correct? New to dual_iso…  :-X

Many thanks

Tim
5D3 1.1.3
5D2 2.1.2