114Mb/s Magic Lantern test!

squig

squig

Veteran
I've been running some tests with Magic Lantern 0.1.9 and I recorded a high detail shot with a 35mm lens @ 114Mbps! Unfortunately it would only record for 1 second at that bit-rate but I can record a few minutes at around 60Mbps with a Sandisk extreme 8Gb 60MB/s card. I've tested a 30MB/s Sandisk and it's too slow for any sustained higher bit-rate recording. I've also run some tests with Transcend 16Gb 400x card and it seems a little slower than the Sandisk 60MB/s card. I'll get my hands on a faster 90MB/s card and run some more tests. I've been shooting everything handheld at 1250 ISO and in low light to really push the codec. At around 60Mb/s there's a noticeable improvement with macro-blocking.

Sometimes when you try to go into live view after loading magic lantern nothing happens just a black screen, just hit the menu button then go into live view.
 
I just ordered a Lexar 600x 16Gb card, it appears to have the fastest sustained write speed on Canon DSLRs. I'll run some tests when it arrives next week.
 
I wonder if you were attach a WFT-E4A Wireless Attachment (also allows recording to a USB HD, up to 1TB) to the camera and recorded directly to hard drive would you be able to sustain these high bit rates?
 
Littleton said:
I wonder if you were attach a WFT-E4A Wireless Attachment (also allows recording to a USB HD, up to 1TB) to the camera and recorded directly to hard drive would you be able to sustain these high bit rates?
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You are likely to bump in to the WiFi & USB limitations a long time before exceeding the write speed of the faster cards.
 
would love to see a framegrab @ 114mbps

If you do some locked down shots, please record a normal version of the clip too, for comparison.
 
Matthew Bennett said:
Whoah - the 5d just went 'GH1???? What's ahppening!!!
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It's kind of funny. Of all the things wrong the 5D the bitrate is not one of them! I just hope that has a good result and not making the moire and aliasing pop even more vividly.

Is there any posted footage with this hack?
 
I shot some footage at around 70Mb/s that I'll try to put up on vimeo tonight. Frame grabs don't really show any real difference. The difference is mostly in solid blocks where compression artifacts are less apparent. I've been wondering myself whether the aliasing and moire is more apparent, have to do some more tests including some extreme low light stuff. Tramm has it set to a variable bit rate, I think a constant bit rate might work better especially in low light.
 
Not sure the aliasing and moire could be worse. Even though the codec is bitrate limited, it still catches it and then compresses it. This hack wouldnt give any sharpness increase, maybe cleaner mids? Might need to try it.
 
Any increase or stabilization in bitrate is a boon for the image - just look at how insanely robust the GH1 images are 50mbps vs. the Mark II at 40ish mbps.

The dream here is to expose a wee bit low and then have your way with characterizing the image curve - with no noise or macro-block penalties.

Nice!
 
Hopefully Tram can change it to a constant bit-rate. The variable bit-rate is overloading the cf card with high detail well lit stuff and recording low bit-rates in low light. I think CBR should ensure sustainable write speeds in excess of 70Mb/s perhaps even 80Mb/s with a 600x card. I've been trying to slightly underexpose, something that was a big no no for me before. I tried uploading some raw footy to megaupload but the damn thing crashed at the end of a 3hr upload!
 
If you film a finely graduated something - like a white wall with a shadow on it could one see the difference in a still?

S
 
For all you pixel peepers out there here's one straight out of the camera @ 68Mb/s- http://www.megaupload.com/?d=U23STMNG

Shot with a Leica 60mm f/2.8 macro @ f/5.6. From memory I think it was 320 ISO. I'll try to get around to posting some 1250 ISO low light stuff.
 
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morgan_moore said:
If you film a finely graduated something - like a white wall with a shadow on it could one see the difference in a still?

S
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I don't think you'll notice much of a difference in a still, it's the compression artifacts in low light and underexposure where it will make a difference.
 
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