Author Topic: 5k raw 24p potential?:continuous 3840x1320 with anamorphic lens  (Read 5167 times)

mlrocks

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1. x5 zoom
2. 1920x1320 24 p raw
3. anamorphic 2x to compress 2x info, now 3840x1320
it is 4k raw now with 3:1 aspect ratio.

mlrocks

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Re: continuous 3840x1320 with anamorphic lens
« Reply #1 on: July 20, 2016, 06:19:56 AM »
i see people always apply a decompression factor for slow mo raw video in 720 60p mode, from 1920x500 to 1920x810. I don't know the reasoning behind this. If this is appliable to 24p in 720 60p mode, then vertical lines can reach wow 2200 (1320x1.6), then 5k (2500x1320) raw can be recorded for maybe 9 seconds in crop mode, enough for most creative works. It is simple and easy, record raw mlv in 720 60p mode at 2500x1320 24p with an anamorphic 2x lens. then apply the decompression factors vertically and horizontally in postprocessing.
this does not need to be in crop mode, in full sensor mode 1920x1290 can be recorded and expanded to 3840x2000 continuously.
ml really rocks. wow.


mlrocks

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Re: 5k raw 24p potential?:continuous 3840x1320 with anamorphic lens
« Reply #3 on: July 27, 2016, 07:01:09 AM »
follow up:

just did a quick test with my 5d3:
I. in full sensor mode,
1. 720p 60p slow mode, i choose 24p 1920x1280 3:2, ml does not allow me to do that, it automatically changes to 1920x670, reminding to add a decompression ratio of 1.67 in post. i did a short test, the 1080 lines visual information is indeeded compressed into 670 lines, so it is not simple cropped, but like a vertical anamorphic effect.
2. if i add a 2x anamorphic lens or adapter (waiting to set up mine yet), 1920x670 will finally be 3840x1280 3:1 uhd/4k (horizontal anamorphic ratio of 2 and vertical anamorphic ratio of 1.67).
3. by calculation, 1920x670=1.4 MB/s, so 60 fps is theoratically possible with a card writing speed of 84 MB/s. on my machine this only works for a short 3 seconds although i saw the writing speed is about 80 MB/s. i use a sandisk extreme pro 128gb 160 MB/s CF card and a  sandisk 80MB/s SDHC 32 GB card. I installed magic lantern system files on the sd card. maybe the sd card is not fast enough for ml system files? no clue.
4. interestingly, theoratically, 1920x670 24p should be possible with my 650d within the writing limit of 40 MB/s. this is significantly, a rebel camera can do super35 full sensor 3840x1280 3:1 widescreen 24 uncompressed raw!

II. in 5x zoom crop mode,
1. calculate the 4k 2k 1080p mode back to compressed resolution:
wide   on camera res.       high         on camera res.
4096   2048      2160   1293.4131736527
3840   1920      2160   1293.4131736527
3996   1998      2160   1293.4131736527
2048   1024      1080   646.7065868263
1920   960      1080   646.7065868263
2. choose the closest resolution in the ml menu, record 24 p raw. i can do 2048x1320 aspect ratio 1.55:1.

suggestion to Alex:
Alex, could you please add these calculated resolution into ml resolution pull down menu? So that we can get exact 4k and can record longer.

question to everyone:
is this anamorphic codec just number playing or real visual information compression?


i

Frank7D

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Re: 5k raw 24p potential?:continuous 3840x1320 with anamorphic lens
« Reply #4 on: July 27, 2016, 04:53:46 PM »
Any anamorphic shooting will not allow you to record more information, but gives you a different aspect ration without losing information (as you would if you cropped the top and bottom of a normal clip).

mlrocks

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Re: 5k raw 24p potential?:continuous 3840x1320 with anamorphic lens
« Reply #5 on: July 27, 2016, 06:11:15 PM »
thanks, frank7d. so it is better than Cinemark cropped mode but not truly 4k.

mlrocks

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Re: 5k raw 24p potential?:continuous 3840x1320 with anamorphic lens
« Reply #6 on: July 27, 2016, 06:15:36 PM »
I just did a quick test on my 650d. comparing to 5d3, 650d has a sensor almost the same as super 35mm film camera, which is why cinematographers like 7d more than 5d, to adapter cinema lenses.

in full sensor 720p 60p mode,
1. I can get 24p 1792 with an aspect ratio of 16:9 for 27 seconds. the whole sensor is used for raw video so that low light is good.
2. I can get 24p 1792 with an aspect ratio of 2.40:1 continuously. for 10% scaling up, this is full hd cinema footage, which was Hollywood's standard 10 years ago. very useful to me.
3. I can get 24p 1600 with an aspect ratio of 3:2 continuously. by applying an anamorphic lens, this is psudo continuous 3k with an aspect ratio of 3:1.

in 5x zoom mode, the compression does not apply.

mlrocks

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Re: 5k raw 24p potential?:continuous 3840x1320 with anamorphic lens
« Reply #7 on: July 27, 2016, 06:22:53 PM »
for 5d3, in 5x zoom 720p 60p mode, the maximal resolution is 3500x1320. this was not practical without the compression factor, but now it can record much longer and 5d3's 3.5k mode seems very applicable to a lot of creative scenarios.

mlrocks

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Re: 5k raw 24p potential?:continuous 3840x1320 with anamorphic lens
« Reply #8 on: July 27, 2016, 10:20:12 PM »
I just did a quick test on my 5d3, basically the compression factor is only working in full sensor 720p 60p mode, not in 5x zoom cropping mode.

So I like the two resolution sets most on my 5d3:
1. 1920x1080 24p continuous in full sensor mode, native 16:9 widescreen, can be expanded to 32:9 with an anamorphic lens;
2. 3520x700 24p in 5x zoom mode, native 5:1 ultrawidescreen.

And I like one resolution set most on my 650d:
1. 1792x584 24p in full sensor 720p 60p mode (27 seconds), native 16:9, 32:9 with an anamorphic lens.

Now, I understand that anamorphic effect only affects view angle, not detail collecting on sensor. Hopefully someone can explain the reason behind the vertical compression factor, because it is not by the lens, but by the camera itself.

budafilms

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Re: 5k raw 24p potential?:continuous 3840x1320 with anamorphic lens
« Reply #9 on: September 29, 2016, 09:53:10 PM »

@mlrocks
"I just did a quick test on my 650d. comparing to 5d3, 650d has a sensor almost the same as super 35mm film camera, which is why cinematographers like 7d more than 5d, to adapter cinema lenses".

You have to write with facts. Non opinions. Or say first " I think".
ML site is the " Core" of ML on internet, don't use it like a personal blog by a wedding filmmaker.

Thanks.