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Record times?
Posted: Tue May 31, 2022 9:01 pm
by zakray
I notice the recording formats PDF (
https://www.arri.com/resource/blob/2773 ... 4-data.pdf) is blank for frame size (in MB).
Can we expect similar file sizes / record times for the Alexa35 as for previous Alexas? E.g. the 4096x2160 mode will be the same amount of space in ProRes, ArriRaw and HDE ArriRaw?
Re: Record times?
Posted: Wed Jun 01, 2022 1:26 am
by Anders Holck
Hi.
Page 33 of the excellent FD times Alexa 35 special article has the chart:
https://www.fdtimes.com/pdfs/free/115FD ... 04-150.pdf
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Re: Record times?
Posted: Wed Jun 01, 2022 3:58 am
by zakray
Thanks Anders! It seems the runtimes are fairly different between Jon Fauer's numbers and, for example, the Mini LF using the Arri Formats and Data Calc. For example, the Arri Calc finds 2 hrs for ProRes444 @ 4K, whereas FDTimes says 1:46. Is this accurate or some difference in how they're measuring?
I also notice he doesn't mention HDE anywhere.
Re: Record times?
Posted: Wed Jun 01, 2022 8:32 pm
by Anders Holck
Hi.
HDE is done during offload so does not affect camera data rates and record time. Im not sure if going from 12 bit ARRIRAW to 13 bit will affect the HDE efficiency, but in my experience between 40-45% reduction is what you get in the real world after you offload. around 10% more data that ProRes4444 and 20% less than ProRes4444XQ
I'm not sure why the ARRI calculator says over 2 hrs on a 1TB codex card. I believe the formatted space on a 1 TB card is 960GB.
Note that all ProRes flavours is VBR, so exact running time and bitrate is dependent on image content and amount of information. Shooting small green screen elements with a solid green out of focus background at iso 200 might cram more material on a 1TB card.
Just checked and the ARRI calculator also says that 24 fps UHD ProRes4444 is 535 GB/h, but two hours is then 2 x 535 GB = 1070 GB, that will definitely not fit on a 960GB card.
I use my own spreadsheet to prep productions using real world recording tests and some interpolated data and I have 1h45m at UHD@24fps on a 1TB card.
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Re: Record times?
Posted: Thu Jun 02, 2022 1:48 am
by zakray
Ok, so it sounds like the ProRes bitrates are probably the same. Comparing your ArriRaw record times to Fauer's, it would seem like the 13-bit ArriRaw does take up more space.
Nice spreadsheet by the way.
Re: Record times?
Posted: Sun Jul 03, 2022 6:49 pm
by Anders Holck
Fyi. the datacalculator has been updated with all the Alexa 35 datarates:
https://www.arri.com/en/learn-help/lear ... calculator
13-bit ARRIRAW seems to be 8-9% larger than12-bit, just as the added bit would indicate. HDE rates mirrors that, so same efficiency as before.
ProRes rates seems to be a little on the lower side compared to the other cameras in the calculator, not sure it means anything other that ProRes being VBR is hard to spec unless you do it with the exact same time. For example ProRes 4444XQ in HD / 24 fps datarate says 403 mbit, while all other Alexas says approx. 450 mbit. Not sure if less sensor noise will explain the difference, as one would expect the ProRes4444XQ to be larger if all 12 bits is now containing actual image data.
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Re: Record times?
Posted: Sun Aug 21, 2022 11:56 pm
by Osbamas
Anders Holck wrote: Wed Jun 01, 2022 8:32 pm
Hi.
HDE is done during offload so does not affect camera data rates and record time. Im not sure if going from 12 bit ARRIRAW to 13 bit will affect the HDE efficiency, but in my experience between 40-45% reduction is what you get in the real world after you offload. around 10% more data that ProRes4444 and 20% less than ProRes4444XQ
https://tonfilm.online/
I'm not sure why the ARRI calculator says over 2 hrs on a 1TB codex card. I believe the formatted space on a 1 TB card is 960GB.
Note that all ProRes flavours is VBR, so exact running time and bitrate is dependent on image content and amount of information. Shooting small green screen elements with a solid green out of focus background at iso 200 might cram more material on a 1TB card.
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Just checked and the ARRI calculator also says that 24 fps UHD ProRes4444 is 535 GB/h, but two hours is then 2 x 535 GB = 1070 GB, that will definitely not fit on a 960GB card.
I use my own spreadsheet to prep productions using real world recording tests and some interpolated data and I have 1h45m at UHD@24fps on a 1TB card.
Screen Shot 2022-06-01 at 20.29.14.png
Well, very interesting.