canon rumors FORUM

Gear Talk => EOS Bodies - For Video => Topic started by: jlev23 on April 27, 2012, 12:11:32 PM

Title: 5D Mark III Magic Lantern wish list poll
Post by: jlev23 on April 27, 2012, 12:11:32 PM
ok, i couldnt think of anything else id want for option 5, but all of the rest would be nice.
i think they are all possible, very possible.
thank you to the guys at Magic Lantern!!!
Title: Re: 5D Mark III Magic Lantern wish list poll
Post by: iMagic on April 27, 2012, 12:21:44 PM
A donation to their cause might grease the wheels!
Title: Re: 5D Mark III Magic Lantern wish list poll
Post by: Policar on April 27, 2012, 12:57:43 PM
If they can improve the in-camera sharpening algorithm so it looks closer to post-sharpened footage but without the compression artifacts and/or increase the bitrate for ALL-I that would be incredible.  Beyond that, focus peaking and zebras would be really nice.  I don't think I'd use any of the other features.
Title: Re: 5D Mark III Magic Lantern wish list poll
Post by: Axilrod on April 28, 2012, 04:52:57 PM
If they can improve the in-camera sharpening algorithm so it looks closer to post-sharpened footage but without the compression artifacts and/or increase the bitrate for ALL-I that would be incredible.  Beyond that, focus peaking and zebras would be really nice.  I don't think I'd use any of the other features.

I have to say even the IPB code grades incredibly well compared to 5DII footage, I wa very happy with the results. 

I'd like to see crop mode, uncompressed HDMI and better framerates at 1080 for sure.  With 17x the processing power of the 5d2 it seems like Canon has to be intentionally limiting the 5D3 or sure.  I'm excited either way.
Title: Re: 5D Mark III Magic Lantern wish list poll
Post by: HurtinMinorKey on April 28, 2012, 08:14:57 PM
Is it true that a camera like the 5D3 can't do 4:4:4 color because the Bayer sensor is set-up as 4:2:2?

Title: Re: 5D Mark III Magic Lantern wish list poll
Post by: peederj on April 28, 2012, 10:56:25 PM
Is it true that a camera like the 5D3 can't do 4:4:4 color because the Bayer sensor is set-up as 4:2:2?

Almost certainly false. The sensor is 22MP and all it needs for video is 2MP...there are plenty of photocells to do whatever one wants with.

People (and I'm citing you as a victim of this, not a culprit) troll around on these boards spewing nonsense about demosaicing and anti-aliasing and OLPF's and the like proving nothing more than "a little knowledge is a dangerous thing." We need an actual authority on camera technology to do a full exposition of what is going on in the camera, but sadly those people rarely post anything like that, because they are usually paid as consultants to the companies making this stuff and don't want to bite the hands that feed them. Canon themselves will just tell you to buy the C300, and if that's not enough for you, the C500.

As for ML, I would just like to see if they can improve the delivered resolution and frame rate control a bit, otherwise the stuff they have already done like peaking and zebras will be a great help thanks.
Title: Re: 5D Mark III Magic Lantern wish list poll
Post by: HurtinMinorKey on April 29, 2012, 01:47:19 AM
^ just to be clear, i wasn't subverted by someone else's posting, i came up with that lunacy on my own.  But I agree with the spirit of your post.

I know that the camera is 22 MP, but the Bayer pattern is set up at a 4:2:2 ratio, which that means that their are effectively 11 M Green photosites, 5.5M red and 5.5 M Blue. 

If they are alternating lines still, then there just isn't enough information for them to end up with a full HD picture using equal ratios of color information without interpolation. 
Title: Re: 5D Mark III Magic Lantern wish list poll
Post by: WarStreet on April 29, 2012, 05:26:21 AM
focus peaking
Title: Re: 5D Mark III Magic Lantern wish list poll
Post by: syder on April 29, 2012, 06:48:53 AM

I know that the camera is 22 MP, but the Bayer pattern is set up at a 4:2:2 ratio, which that means that their are effectively 11 M Green photosites, 5.5M red and 5.5 M Blue. 

If they are alternating lines still, then there just isn't enough information for them to end up with a full HD picture using equal ratios of color information without interpolation.

When expressing chroma subsampling ratios the 4:2:2 doesn't refer to primary colours as G:R:B, it's Y:Cb:Cr which refers to Luminance (Y) and two colour difference components Blue Difference (Cb) and Red difference (Cr)
Title: Re: 5D Mark III Magic Lantern wish list poll
Post by: daveswan on April 29, 2012, 10:19:05 AM
Just set it up so the wretched thing outputs somewhere near true 1080p resolution.

A 150mbps CBR I-Frame codec would be nice.

A full raster de-moseic of the sensor would certainly give 4:4:4 colour sampling (Not colour *space*, that's something different) as there's plenty of pixels for downsampling
Title: Re: 5D Mark III Magic Lantern wish list poll
Post by: ers811 on April 29, 2012, 01:48:41 PM
I'll go a little outside the box here and say my wish list is:

1. Finish ML Unified for 5D2
2. Everything else
Title: Re: 5D Mark III Magic Lantern wish list poll
Post by: LetTheRightLensIn on April 29, 2012, 03:09:41 PM
ok, i couldnt think of anything else id want for option 5, but all of the rest would be nice.
i think they are all possible, very possible.
thank you to the guys at Magic Lantern!!!

The thing is it is NOT magic.

How are they going to encode, in real time, in all those alternate formats if the camera doesn't have a real time encoder chip for them? (OK, it might be possible if they use a more general purpose encoding DSP that simple has some of the functions encoding needs and it is still mostly programmed in software and not hardware/firmware, I thought the previous ones at least, simply used dedicated, h.264 specific encoding chip I could be mistaken though).

Title: Re: 5D Mark III Magic Lantern wish list poll
Post by: LetTheRightLensIn on April 29, 2012, 03:15:06 PM
I'd love to see crop mode.

1. I'm suspicious the FF 1920x1080p looks a bit soft because the 3x3 blocking from a Bayer sensor doesn't match the scale of the built-in AA filter so they probably have to do some sort of extra smoothing to avoid aliasing. If they made a 2x2 blocking of the type the C300 uses which would give 1920x1080 from about a 1.6x APS-C crop region that blocking would be closer to the native AA filter scale and you might be able to get away without smoothing/blurring and you might a sharper looking 1920x1080 that is still artifact free (maybe just a trace more aliased, but still moire free).

2. For wildlife and other distant object photography crop mode sure as heck helps. 1920x1080 is pretty lo-res when it comes down to it and you jsut don't have much anything to work with using digital zoom on captured footage so a true 1.6x crop mode at 1920x1080 would put a full TC's worth more detail onto everything and maybe even more than that if my point 1 guess is correct.



The only thing is was Canon so short-sighted that they didn't bother designed the sensor with the ability to do non-skipped 2x2 C300-like sampling?? I sure hope not. But they have been amazingly blind before (witness the absurdity of thinking it made sense to release the 5D2 without manual video control, etc.)
Title: Re: 5D Mark III Magic Lantern wish list poll
Post by: LetTheRightLensIn on April 29, 2012, 03:17:08 PM
ok, i couldnt think of anything else id want for option 5, but all of the rest would be nice.
i think they are all possible, very possible.
thank you to the guys at Magic Lantern!!!

option 5 is easy all the necessary basics such as:
focus peaking
zebra stripes
allowance for more bps for compression and locking all-i to CBR
Title: Re: 5D Mark III Magic Lantern wish list poll
Post by: HurtinMinorKey on April 29, 2012, 07:54:49 PM
When expressing chroma subsampling ratios the 4:2:2 doesn't refer to primary colours as G:R:B, it's Y:Cb:Cr which refers to Luminance (Y) and two colour difference components Blue Difference (Cb) and Red difference (Cr)

I think that they are one in the same (G:R:B and Y:Cb:Cr) in this application, but I'm not certain.
Title: Re: 5D Mark III Magic Lantern wish list poll
Post by: psolberg on April 30, 2012, 07:23:14 AM
I wish they would improve the soft output of hte 5DIII to match the GH2. unlikely since it seems you have to remove the OLP to get any sharpnesss out of hte 5DIII video.
Title: Re: 5D Mark III Magic Lantern wish list poll
Post by: HurtinMinorKey on April 30, 2012, 04:07:51 PM
Does anyone know where you can download a editor that can edit Canon firmware ?
Title: Re: 5D Mark III Magic Lantern wish list poll
Post by: peederj on May 01, 2012, 06:56:04 PM
I wish they would improve the soft output of hte 5DIII to match the GH2. unlikely since it seems you have to remove the OLP to get any sharpnesss out of hte 5DIII video.

I have never seen any evidence that OLPF removal, which will only affect the 22MP image directly, affects the 2MP video in any significant (positive) way. That's a false meme that has even bled into the stills people's vernaculars, and it should be crushed until and unless reproducible, verifiable evidence (i.e. resolution charts, moire charts, etc.) is presented.

The damage to the video is done in the digital downscaling, and if ML can hack into that and provide a better method, the 5D3 will be unleashed. If Canon really wanted to protect the 1DC and C300 from the 5D3, they will have made that inaccessible.
Title: Re: 5D Mark III Magic Lantern wish list poll
Post by: herbert on May 02, 2012, 08:04:35 AM
When expressing chroma subsampling ratios the 4:2:2 doesn't refer to primary colours as G:R:B, it's Y:Cb:Cr which refers to Luminance (Y) and two colour difference components Blue Difference (Cb) and Red difference (Cr)

I think that they are one in the same (G:R:B and Y:Cb:Cr) in this application, but I'm not certain.

The 4:2:2 is a type of chroma sub-sampling.

Since the human eye is more responsive to brightness than to colour it is possible to save space when storing an image by storing more brightness values than colour values. This is done by converting the RGB colour space to Y:Cr:Cb. The colours (Cr,Cb) are then sampled less than the brightness (Y) when the image is saved.

Note that the Y:Cr:Cb colour space can be converted back to RGB (it is simply a different 3-dimensional representation of the same data). Missing Cr:Cb values are filled in from surrounding values and then each pixel is converted back. This is done when viewing the movie.

Check out the Wikipedia article that has a few picture showing how the image stored in different sub-sampling schemes looks:

http://en.wikipedia.org/wiki/Chroma_subsampling (http://en.wikipedia.org/wiki/Chroma_subsampling)

Quote
The subsampling scheme is commonly expressed as a three part ratio J:a:b

J: horizontal sampling reference (width of the conceptual region). Usually, 4.
a: number of chrominance samples (Cr, Cb) in the first row of J pixels.
b: number of (additional) chrominance samples (Cr, Cb) in the second row of J pixels.

From this you can appreciate the 4:2:0 is worse than 4:2:2 since the former will only change colour every other horizontal line. Both will change colour every other vertical line. The holy grail is 4:4:4 since that does not throw any information away. If also takes up more space.

The second factor in quality is how many bits are used to store the data. Canon DSLRs use 8-bits (values from 0-255). The Cinema cameras use 10-bit (0-1023) or 12-bits (0-4095) so get a lot more gradation of tone. This also takes more space.

I believe the combination of sub-sampling, bit-depth, image size (e.g. 1920x1080) and frame rate (e.g. 24/s) are all combined to create a bit-rate for the movie. This is how many numbers are passed through the system per second. It is this final number that states the overall quality of the system and also the type of storage media requirements involved.
Title: Re: 5D Mark III Magic Lantern wish list poll
Post by: HurtinMinorKey on May 02, 2012, 01:49:59 PM
Note that the Y:Cr:Cb colour space can be converted back to RGB (it is simply a different 3-dimensional representation of the same data). Missing Cr:Cb values are filled in from surrounding values and then each pixel is converted back. This is done when viewing the movie.


This is what I was saying, they are the same essentially in terms of the relevant data they carry, with maybe a affine transformation between them.  Which is why I thought that MAYBE, the Bayer pattern, which is like a native 4:2:2 sample, might have something to do with preventing a 4:4:4 output, without serious processing/interpolation.

Also, 8bit is nice, but since monitors are only 8-bit(RGB totalling 24)  the extra bits are ONLY use full in post. Theoretically the extra-bits don't give you a better picture, if you have the proper white-balance/exposure to begin with.

I think I've read that wiki article 10 times, great stuff.
Title: Re: 5D Mark III Magic Lantern wish list poll
Post by: psolberg on May 03, 2012, 01:17:23 PM
if the data is binned before readout by low level sensor circuits as some have suggested, I doubt a firmware induced process change on the post binned data will help resolution. The reason the D800 beats the 5DmkIII in perceived resolution is because internally it takes a 2240 x 1260 frame resulting from demosaic (yes, that's 1260P video) and downscales it decently to 1080p. Although the OLP delete mod on the 5DIII does help things.

I think the most realistic expectations from tweaked firmware should at least bump the bitrate so that the codecs don't fall apart so easily under motion. That has so far it is the weakness of both the D800 and 5DmkIII (although not an issue if you use the 4:2:2 HDMI out on the D800 + ninja 2.0)

ultimately, I decided to skip the 5DIII since it was clear Canon is not going to put the hardware in it that would cause it to cannibalize its precious C line.
Title: Re: 5D Mark III Magic Lantern wish list poll
Post by: Policar on May 03, 2012, 04:22:21 PM
if the data is binned before readout by low level sensor circuits as some have suggested, I doubt a firmware induced process change on the post binned data will help resolution.

The resolution isn't really that bad, though, if you look at resolution charts.  Something like 800-900 lines, which isn't terrible.  It's the apparent softness that's an issue, and that's compounded by the bad sharpening algorithm that you can't turn up at all or you get halos.  It's not an elegant solution, but sharpening in post really does help.  But sharpening also brings out compression artifacts.  If Canon or ML could improve the camera's sharpening algorithm (and add focus peaking and zebras) I would be thrilled with this camera for video.

There's little chance of more resolution out of the camera, but either less sharpening or a higher bitrate (though 90Mbps seems pretty high as is in terms of SD card buffer) would make a big difference.  Clean HDMI out would be fine, but at that point, just buy an FS100 instead.  The point of dSLRs is their size and ease of use; external capture can be a pain.
Title: Re: 5D Mark III Magic Lantern wish list poll
Post by: syder on May 03, 2012, 07:40:39 PM

I believe the combination of sub-sampling, bit-depth, image size (e.g. 1920x1080) and frame rate (e.g. 24/s) are all combined to create a bit-rate for the movie. This is how many numbers are passed through the system per second. It is this final number that states the overall quality of the system and also the type of storage media requirements involved.

Not really... The codec - the type of compression used to store the data is massively important in understanding bitrates. For example the 5DMIII has a 90mb/s intraframe codec and the far lower long GOP codec, which have the same subsampling ratio, image size, bit depth and frame rate.

Describing the bitrate as the 'overall quality of the system' is also quite misleading... I'd take the 1080p 24mb/s footage off a D800 over the 25mb/s 576i minidv footage off a pd150 or xl1 anyday