Author Topic: Is MLV using the full width of the sensor?  (Read 4907 times)

Walter Schulz

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Re: Is MLV using the full width of the sensor?
« Reply #25 on: May 14, 2020, 03:24:55 PM »
I think we are all wondering where the number 1.1 comes from. Please share the steps of your calculation.

Levas

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Re: Is MLV using the full width of the sensor?
« Reply #26 on: May 14, 2020, 04:00:29 PM »
The crop is neglible. You can record 1856 pixels wide, while full width is 1872 pixels.
So you only loose 16 pixels, on a total of 1872. That’s less then 1%. Nobody will notice.
Cropfactor is 1872/1856 = 1.009
So tecnically you would not even be lying if you say the 5d2 has a cropfactor of 1.0 ;)
Your 35mm lens becomes a 35 x 1.009 = 35.3mm lens 😋

Milk and Coffee

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Re: Is MLV using the full width of the sensor?
« Reply #27 on: May 14, 2020, 07:34:21 PM »
I think we are all wondering where the number 1.1 comes from. Please share the steps of your calculation.

Hey Walter. If you look on this site, https://rawcalculator.netlify.app/calculator_desktop listed at the bottom is "crop factor." The "1.Xx" factor i'm using is also listed in sensor specifications of common camera reseller websites. IE: APS-C= 1.5x crop. Does that help clear things up?

@Levas, thanks for helping clear that up for me!! So technically speaking in 3x3 mode, the 6D can achieve a wider field of view than the 5D2 (since the 5D2 has this "black pixel" phenomenon?)
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Walter Schulz

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Re: Is MLV using the full width of the sensor?
« Reply #28 on: May 14, 2020, 07:43:21 PM »
Sorry, but it is completely not transparent what this crop factor means. Never paid attention to it before. Looks like it's just taking 1920 as 100 percent and using the horizontal pixel count for liveview to compute it. And that's just wrong and doesn't make any sense in uncropped mode.
You should ignore this number for modes not using crop.

And APS-C factor in Canon realm is 1.62.

Milk and Coffee

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Re: Is MLV using the full width of the sensor?
« Reply #29 on: May 14, 2020, 09:38:01 PM »


And APS-C factor in Canon realm is 1.62.

Yes, I know. 1.5x was just an example. In other words I am referring to “Focal Length Multiplier” (AKA Crop Factor.)

And I think the ML RAW Calculator’s calculations are correct. At least to my math, the Focal Length Multiplier (Crop Factor) is calculating correctly based on the selected resolution setting. 
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Levas

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Re: Is MLV using the full width of the sensor?
« Reply #30 on: May 14, 2020, 09:41:55 PM »
@Levas, thanks for helping clear that up for me!! So technically speaking in 3x3 mode, the 6D can achieve a wider field of view than the 5D2 (since the 5D2 has this "black pixel" phenomenon?)

It's really nothing, it's less then 1%, it's a non-issue.
In real world, nobody could tell there are 16 pixels missing on the side.

But here some more to think about  ;D :
The 6d can use the whole sensor width, which is 1824 pixels in 3x3 mode.
The 5d2 can do 1856 pixels(without black border) in 3x3 mode.
So 5d2 has 32 pixels more in 3x3 mode...what do you want more pixels nobody will notice, or more field of view nobody will notice  :P
But there is more, search in google for the real sensor size of the 6d and you will find out it's not 36mm like the 5d2, but slightly smaller, the 6d has an 35.8mm wide sensor  ???
So we're missing slightly field of view on the full-frame 6d, have you ever heard anyone wine about that, exactly, it's so small, no problem  :P

But there is another catch here, what we call whole sensor width, is actually whole width of sensor used in photo mode.
But as we know, there are unused pixels on the side of the sensors, the black borders.
Canon 5d2 has a 160 pixels wide black column on the left side and the 6d 'only' has 80 black pixels wide column on the left side...

So if we all sum these up, I think it's fair to say they can both film in full frame a.k.a 1.0 crop factor  8)

Milk and Coffee

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Re: Is MLV using the full width of the sensor?
« Reply #31 on: May 15, 2020, 06:06:47 AM »
@Levas thanks so much for all the great info! Very encouraging and relieving! As you can probably tell, I’m trying to figure out which camera to buy lol.

Out of further curiosity, you said “whole sensor used in photo mode.” Are the black pixels suddenly not black anymore? Is the FOV wider in photo mode? Or do you mean something like “full resolution?” (The ability to capture all 5000ish pixels in photo mode)

So with all the caveats that you listed, the crop factor (3x3 full frame mode) could loosely be called the same between the 6D and 5D2. NOW I think the winner is the 5D2 because if it’s faster write speed capabilities. We could pack in more vertical resolution on standard 24fps.

Would you agree?
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Levas

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Re: Is MLV using the full width of the sensor?
« Reply #32 on: May 15, 2020, 04:36:54 PM »
Black pixels are still black in photo mode.
I meant that we can divide the photo resolution by 3 to get the maximum video resolution in 3x3 mode.

Yes 3x3 full frame mode is the same between 6d and 5d2.
The faster write speed of the 5d2 makes it the better option for video.

But if money is no problem, and you want the best camera with Magic Lantern support, you should go for the 5d3.

 


Milk and Coffee

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Re: Is MLV using the full width of the sensor?
« Reply #33 on: May 16, 2020, 07:00:38 PM »
Thanks @Levas! I thought I read somewhere that there is a module that speeds up write speed on the 6D? Do you know what that is? I can’t find it anywhere.

Also Andrew Ried states here (https://www.eoshd.com/raw-video/magic-lantern-raw-video-current-camera-capabilities-updated-2017/) “ Note however, that older DIGIC IV (4) cameras like the 5D Mark II, 7D and 50D do not have 10bit-12bit capability, only uncompressed 14bit raw.”

Can the 5D2 do 10bit now? (That EOSHD post was from 2017)
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masc

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Re: Is MLV using the full width of the sensor?
« Reply #34 on: May 16, 2020, 08:43:55 PM »
Can the 5D2 do 10bit now?
Yes, it can.
5D3.113 | EOSM.202

reddeercity

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Re: Is MLV using the full width of the sensor?
« Reply #35 on: May 17, 2020, 02:52:52 AM »
I did a quick test build with no image offset , in other words I recorded the whole sensor black border & all .

First 3x3 (FHD) 2040x1267 , this is the raw_image dump
(I didn't adjust the black level , sorry it 128 should be 112 for 10bit )


Here the 5D2-3x3-Raw_Dump_dng-ppm-png.zip
If you do a crop in IrfanView you get 1880x1250 ,
which the offset is correct in raw.c  160 pixels left & 18 pixel from the top
Though this would help people understand better how the sensor is configured  ;D

Levas

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Re: Is MLV using the full width of the sensor?
« Reply #36 on: May 17, 2020, 11:17:31 AM »
Thanks @Levas! I thought I read somewhere that there is a module that speeds up write speed on the 6D? Do you know what that is? I can’t find it anywhere.

Yes, there's a module which improves the write speed of the SD card. (also works for other cams, not sure on which camera's it is used, but the eos-m builds from Danne use it too)
Here's a link to the topic of this module:
https://www.magiclantern.fm/forum/index.php?topic=12862.msg199224#msg199224

Without this sd_uhs module, the 6d has a write speed of about 39Mb/s and with the module it reaches about 57Mb/s write speed.
Doesn't work on all SD cards, you need one that is compatible with the settings. (Sandisk extreme pro 95Mb/s and 170Mb/s work)
So even with the module, write speed is still lower then 5d2. (Not sure what the write speed of 5d2 is exactly, but it's probably about 75Mb/s ? )

But besides 12 and 10 bit raw recording, there is also lossless 14 and 12 bit recording, only available on digic 5 cameras.
The amount of lossless compression you get depends on the scene, the brighter the scene, the less compression you get.
For normal, good exposed scenes you get probably around 25% / 35% compression.
So with this advantage of lossless compression, you can record about the same amount of raw data as the 5d2.

But to be able to do that, you need the sd_uhs module and a compatible card.

For plain, 3x3 mode, full-view, mode video recording I think you can get about the same results, resolution and recording time wise.
But with the 5d2, you're not depended on how good the lossless compression will be, which could be a lot less on very bright scenes.
Hard to choose, for raw video, probably very comparible camera's (5d2 and 6d)

The 5d3, has both, high compact flash recording speed (about 100Mb/s) and lossless raw compression.

Milk and Coffee

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Re: Is MLV using the full width of the sensor?
« Reply #37 on: May 18, 2020, 04:14:53 AM »
I did a quick test build with no image offset , in other words I recorded the whole sensor black border & all .

First 3x3 (FHD) 2040x1267 , this is the raw_image dump
(I didn't adjust the black level , sorry it 128 should be 112 for 10bit )


Here the 5D2-3x3-Raw_Dump_dng-ppm-png.zip
If you do a crop in IrfanView you get 1880x1250 ,
which the offset is correct in raw.c  160 pixels left & 18 pixel from the top
Though this would help people understand better how the sensor is configured  ;D

So including the black pixels, the sensor is actually larger than 36mmx24mm, yes?
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Milk and Coffee

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Re: Is MLV using the full width of the sensor?
« Reply #38 on: May 18, 2020, 04:36:18 AM »
Yes, there's a module which improves the write speed of the SD card. (also works for other cams, not sure on which camera's it is used, but the eos-m builds from Danne use it too)
Here's a link to the topic of this module:
https://www.magiclantern.fm/forum/index.php?topic=12862.msg199224#msg199224

Without this sd_uhs module, the 6d has a write speed of about 39Mb/s and with the module it reaches about 57Mb/s write speed.
Doesn't work on all SD cards, you need one that is compatible with the settings. (Sandisk extreme pro 95Mb/s and 170Mb/s work)
So even with the module, write speed is still lower then 5d2. (Not sure what the write speed of 5d2 is exactly, but it's probably about 75Mb/s ? )

But besides 12 and 10 bit raw recording, there is also lossless 14 and 12 bit recording, only available on digic 5 cameras.
The amount of lossless compression you get depends on the scene, the brighter the scene, the less compression you get.
For normal, good exposed scenes you get probably around 25% / 35% compression.
So with this advantage of lossless compression, you can record about the same amount of raw data as the 5d2.

But to be able to do that, you need the sd_uhs module and a compatible card.

For plain, 3x3 mode, full-view, mode video recording I think you can get about the same results, resolution and recording time wise.
But with the 5d2, you're not depended on how good the lossless compression will be, which could be a lot less on very bright scenes.
Hard to choose, for raw video, probably very comparible camera's (5d2 and 6d)

The 5d3, has both, high compact flash recording speed (about 100Mb/s) and lossless raw compression.

So to summarize: the 5D2, CANNOT do lossless compression because of the DIGIC 4 processor, but can write up to 75mb/s with the CF card. And the 6D CAN do lossless compression because of the DIGIC 5 processor, but has limited write speed to the SD card (but can be sped up with the SD_UHS module, while still only reaching ~51mb/s?)

Is there any cautions using the SD_UHS module?
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reddeercity

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Re: Is MLV using the full width of the sensor?
« Reply #39 on: May 18, 2020, 07:12:06 AM »
So to summarize: the 5D2, CANNOT do lossless compression because of the DIGIC 4 processor
No,  that's not right -- D4/5d2/50d can do lossless compression ,  there a bug in saving of the lossless dng/mlv that I'm still working on.
So it's about 90% implemented this where I left off here , just haven't got back there yet wanted to have the 50d working in crop_rec before I continue on.

Levas

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Re: Is MLV using the full width of the sensor?
« Reply #40 on: May 18, 2020, 10:38:49 AM »
Oops, didn't know that, sorry for the confusion.
In that case the 5d2 might be the better option, as it is now, it's about the same as the 6d.
But if lossless raw recording is achieved in the future, it has much better raw data recording capability.

Milk and Coffee

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Re: Is MLV using the full width of the sensor?
« Reply #41 on: May 23, 2020, 06:37:00 PM »
I did a quick test build with no image offset , in other words I recorded the whole sensor black border & all .

First 3x3 (FHD) 2040x1267 , this is the raw_image dump
(I didn't adjust the black level , sorry it 128 should be 112 for 10bit )


Here the 5D2-3x3-Raw_Dump_dng-ppm-png.zip
If you do a crop in IrfanView you get 1880x1250 ,
which the offset is correct in raw.c  160 pixels left & 18 pixel from the top
Though this would help people understand better how the sensor is configured  ;D

So including the black pixels, the sensor is actually larger than 36mmx24mm, yes?
Gear: Canon 5D Mark II

Levas

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Re: Is MLV using the full width of the sensor?
« Reply #42 on: May 23, 2020, 08:13:04 PM »
No the sensor is 36x24mm.
The sensor has a lot of pixels, but doesn't use them all for actual photo/video.
Small parts at the sides/top/bottom are not used for the actual photo/video pixels, these are what we call the black pixels.
These pixels are probably used to reduce noise/calibrate column gain/determine black level and such stuff.

Did some more digging on the 6d, turns out there are some unused pixels there as well, just like with the 5d2.
6D can do, 5496x3670 (CR2 files are 5472x3648).
I think these pixels are available in CR2 files as well, but masked out with exif function.
Standard ML video on the 6d is 1824x1026.
But now with this new information, I created a crop preset which does 1832x1030.



Milk and Coffee

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Re: Is MLV using the full width of the sensor?
« Reply #43 on: May 24, 2020, 05:28:22 AM »
@Levas please see image below. (Let me know if it doesn’t work.)

https://ibb.co/SwZRjck

Looking at the green boxes, which image is the sensor’s 36mm x 24mm area?

If it is the left, then roughly 8% to 10% of the 36mm x24mm sensor is “cropped” by black pixels?
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Levas

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Re: Is MLV using the full width of the sensor?
« Reply #44 on: May 24, 2020, 10:45:47 AM »
I would guess, that the left image is right. I think camera brands report their sensor size on physical size and not on the amount of active pixels used for the photo size.
But I'm not 100% sure, if you really want to know you should ask Canon if the sensor width is for the total amount of pixels on the sensor, or is the sensor slightly bigger and is the 36x24mm the size for the active pixels.
 
But the frame you're looking at, is not what it looks like.
The black borders are readout pixel for pixel, there is no binning in the black border part.
So what you see is a black border made out of ~160 black pixels, readout one by one, no binning there, and the rest of the width is ~1872 pixels binned together(original read from 5616 pixels, each 3 pixels binned together to one)

So not by far 10%, but more like 168(black pixels) / (5792 total pixels((taken from the numbers reddeercity reported few posts earlier) * 100% = 2.9%

Milk and Coffee

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Re: Is MLV using the full width of the sensor?
« Reply #45 on: May 25, 2020, 09:06:19 PM »
But the frame you're looking at, is not what it looks like.
The black borders are readout pixel for pixel, there is no binning in the black border part.
So what you see is a black border made out of ~160 black pixels, readout one by one, no binning there, and the rest of the width is ~1872 pixels binned together(original read from 5616 pixels, each 3 pixels binned together to one)

@Levas & @reddeercity thanks again for all the useful info. See the linked images below.

I mocked up a few images.

If the image @reddeercity was not 3x3 binned, and shot at full resolution - it would look like this? (Black borders are 160px from left. 18px from top.)

https://ibb.co/BsrZJq9

And to confirm I'm understanding correctly, ML handled the image this way? (Green pixels are full pixel readout, and pink area is 3x3 binned)

https://ibb.co/tPG900b
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Levas

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Re: Is MLV using the full width of the sensor?
« Reply #46 on: May 25, 2020, 09:53:34 PM »
Yep.

And to confirm I'm understanding correctly, ML handled the image this way?

Although it's not really a choice of ML to handle it like this, it is just how it is.
Canon designed the sensor or software on the Camera this way.
ML is making use of a raw data video stream already available in camera, and black borders are included :P

Milk and Coffee

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Re: Is MLV using the full width of the sensor?
« Reply #47 on: May 26, 2020, 06:34:49 AM »
@levas thanks for all the info  :D
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Milk and Coffee

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Re: Is MLV using the full width of the sensor?
« Reply #48 on: June 14, 2020, 10:57:54 PM »
Thanks all for the tips! So I have been using the Magic Lantern RAW Calculator https://rawcalculator.netlify.app/calculator_desktop and I will be purchasing the 5d2 soon once I find a good deal.

I see down the page that there is a "Resolution Increment." I will be shooting full frame (1.0x) mostly, and I see that if I select "8px" under the "Resolution Increment," I get the full width binned by 3 at 1880px wide. Whereas if I select "16px" I get 1872px wide.

Can somebody explain a little more about what "Resolution Increment" is, and how it affects the image?
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allemyr

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Re: Is MLV using the full width of the sensor?
« Reply #49 on: June 14, 2020, 11:43:32 PM »
1x and fullframe is different things. If you going to shoot fullframe i can recommed the M3, maybe its still expensice tho idk.