Author Topic: Canon 7D Does ML remove the 24' video recording limit ?  (Read 651 times)

hismaimai8888

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Canon 7D Does ML remove the 24' video recording limit ?
« on: November 22, 2018, 04:46:53 AM »
Hi there,

This Magic Lantern looks really ... magic. Great job!
I wonder if it enables to shoot more than 24'/Gb of video, which is the limit I hit on my Canon 7D with 16GB 400x UDMA CF ?

Thanks for your insights.
Cheers
Công ty rut ham cau quan 12 giá rẻ dịch vụ rút hầm cầu quận 12 uy tín

Walter Schulz

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Re: Canon 7D Does ML remove the 24' video recording limit ?
« Reply #1 on: November 23, 2018, 08:51:37 PM »
ML does not fix 7D's file system limitation: No ExFAT support. File size limit is 4 GB with or without ML. Canon decided to implement a "not that much sophisticated" file handling within this cam (and other Digic 4 cams), too (as you know already). Reaching 4 GB means: Stop recording and restart it. Therefore maximum recording time depends on video resolution.
ML can automate movie restart in native H.264 mode (= MOV recording). You will loose some frames during transistion, though.
BTW: Digic 5 cams do support ExFAT and will stop at 29:59 only. Fun fact: Recording exceeding 4GB will be splitt into file chunks each up to 4 GB! I suppose it is because compatibility with FAT32 devices.

ML can do seamless recording > 29:59 in RAW mode. Only limit: card size, battery and - sometimes - temperature.
Looks like a solution ... but there is a trade off, a serious one: Bandwidth. Uncropped 1728x972 in 24 fps with 14 bit depth will eat up around 67 MByte/s. Needs a fast card and a big one. Do the math ...
Cropping is available (=reduced data rate) but will use a smaller active sensor area  -> reduced FOV.

For other cams there are experimental builds offering reduced bit depth and lossless compression. 7D development is hampered by 7D's dual processor design ...

Oh, and there is HDMI recording, of course. Haven't tested if some of the latest developer wizardry (HDMI without hickups at 29:59) is working for 7D, too.
Photogs and videographers: Assist in proof reading upcoming in-camera help!. Your input is wanted and needed!

fanfzero

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Re: Canon 7D Does ML remove the 24' video recording limit ?
« Reply #2 on: March 16, 2019, 01:47:23 AM »
ML can do seamless recording > 29:59 in RAW mode. Only limit: card size, battery and - sometimes - temperature.
Looks like a solution ... but there is a trade off, a serious one: Bandwidth. Uncropped 1728x972 in 24 fps with 14 bit depth will eat up around 67 MByte/s. Needs a fast card and a big one. Do the math ...

I'm fine with big sizes, so, this means there's a way to do a raw recording on 7D without cutting when it reaches 4GB?

Walter Schulz

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Re: Canon 7D Does ML remove the 24' video recording limit ?
« Reply #3 on: March 16, 2019, 11:48:09 PM »
 The 40 (forty) GB limit for a MLV recording session was removed 4 years ago...
Photogs and videographers: Assist in proof reading upcoming in-camera help!. Your input is wanted and needed!