F5: f5 and 4k options

R

ryaninoz

Well-known member
is it possible to record any kind of compressed 4k with the f5 using an external recorder ? I think 4k is around the corner but a lot of the time 4k raw will be overkill I love the fact that the f55 can record compressed 4k but at twice the price of the f5 I'm not so sure. I could be wrong but it seems that the ax5 just records raw, is there a way to record a smaller file sized 4k from the f5?
 
Not as it's described now, no. There's no 4K output on the 5, other than the proprietary connection from body to AXS-R5
 
PaulReam said:
I wonder if others (brighter than me) are looking at the pin-outs here, with a view to making some special leads?
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I think that would take a very high level of reverse engineering and effort, and an awful lot of money.

Red Epics and Scarlets have the same situation, and nobody's even talked about making 3rd party modules for those cams; there's been a desire for Prores recording for quite a while.
 
Nate Weaver said:
I think that would take a very high level of reverse engineering and effort, and an awful lot of money.

Red Epics and Scarlets have the same situation, and nobody's even talked about making 3rd party modules for those cams; there's been a desire for Prores recording for quite a while.
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This is true. It would be hard to justify the learning curve with the risk of it not working, being too expensive for the market, or Sony announcing something new that would defeat the reason for having a product like that. Things change too fast to bother IMHO. If you want/need 4k - buy 4k. If you cannot afford it, wait.
 
Yeah. Someone could do all the R&D, figure out how to hit a price point of $4k, and then Sony releases a box for $2k that fits on the back of the F5 instead of the 4k recorder, and has the 4k HD-SDI spigots.

Things are moving way too quickly right now. If I wait three years, an Alexa might be a bargain.
 
I wonder if some of the F55 goodies are "software locked" out of the F5 and could be released at some time in the future? Are all the differences truly hardware or perhaps some are software limitations (like S-Log was in the F3).
 
I suspect hardware, at least for some things. Different circuit boards. Internal 4k with compression is almost certainly it's own DSP board for the codec. And remember, the F5 and F55 have different image sensors, so likely differences in how they're handled as well.
 
So if 4k becomes the new HD then the only practical way of working with it for docos ( in terms of file size
) will be with the f55 ? It seems strange that the f5 would be restricted in this way when a range of low cost 4k camcorders with compressed codecs ( and smaller sensors ) have been announced. Why not make the ax5 able to record a lighter 4k in addition to raw ?
 
F5 and F55 have different processors, thus giving the F55 more robust features like internal 4K.

I don't think there is any comparison between any of the Prosumer 4K products (including Sony's) and what can be produced from F5/55

Ned
 
The comparison is that the consumer products have a compressed 4k granted the front end is no where near the same as the f5 however it would be good to have a run and gun 4k option for the f5 even if it required an external recorder. I wonder what the file size difference is between the raw option and the 4k internal codec in the f55 ?
 
ryaninoz said:
I wonder what the file size difference is between the raw option and the 4k internal codec in the f55 ?
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Pretty big difference

XAVC 4K (at 24fps) is about 240mbs, which will get you about 37 minutes on a 64GB SxS Pro+ card (incidentally, this is comparable to Redcode 28 or in the new Red nomenclature, 12:1 compression) Red is wavlet based though, not MPEG4, so apples and oranges a little bit.

Sony's 4K raw is about 68 minutes to a 512GB AXSM card (it's compressed a bit). So even if a 64GB SxS Pro+ card could sustain the data rate of 4K raw, you could only fit 16 minutes of footage on a 128GB SxS card. So Sony's 4K raw is compressed about 3:1, which is the same as the high quality raw option on the F65. It's also about 120MB/sec, pretty fast for a SxS card.

BTW, these numbers are arrived at by working backwards from the bitrates and runtimes Sony published in the FD Times special issue. They've refrained from making specific runtime charts, but they've given all the necessary info in a very roundabout way. I've also done some rounding in the calculations to make the math easier for me, so please go easy on me in 2 moths when my numbers are slightly off.
 
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Nate Weaver said:
Pretty big difference

XAVC 4K (at 24fps) is about 240mbs, which will get you about 37 minutes on a 64GB SxS Pro+ card (incidentally, this is comparable to Redcode 28 or in the new Red nomenclature, 12:1 compression) Red is wavlet based though, not MPEG4, so apples and oranges a little bit.
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My calculations put it closer to 17:1

8.8mp x 10bits per pixel x 2 for yuv 422 x 24fps / 240mbps = 17.6 compression factor
 
This means that XAVC 4k has about the same data rate as ProRes-HQ for HD video which is therefore about 4X less compressed than this new codec (4k has 4 times the data as 2k/HD). I wonder about the editing of XAVC in a NLE since it is so highly compressed. Is this something like trying to edit H.264 footage which is a great format for production but not so good for editing?
 
you're basically asking for the F55 at the price of the F5. If you think you want a camera to use in this fashion, then the camera is already being offered by Sony. Sorry if you do not wish to pay the higher price.
 
lasikdenver said:
This means that XAVC 4k has about the same data rate as ProRes-HQ for HD video which is therefore about 4X less compressed than this new codec (4k has 4 times the data as 2k/HD). I wonder about the editing of XAVC in a NLE since it is so highly compressed. Is this something like trying to edit H.264 footage which is a great format for production but not so good for editing?
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It's going to need a fast computer, yes.

But directly comparing it to Prores is probably not appropriate...Prores is a DCT codec, a great high-bitrate version of older (10 years+) compression tech. XAVC is a cutting edge version of H264, at high bitrates using all i-frames.

I think considering H264 to be inherently bad for editing is a bit over-simplistic. Especially when a lot of the bad rap comes from the technicalities of inter-frame codecs. I-frame only versions of codecs pretty much do away with those problems. Like Sony's XAVC. Pretty much every current NLE has gotten huge behind-the-scenes updates to better deal with the explosion of H264 media in production. They couldn't ignore Canon DSLRs, nor Gopros. FCP tossed Quicktime and upended their entire world in part to embrace the shift. FCPX is now insanely fast at using native H264 media.

Besides...there are an AWFUL lot of smart minds working hard on squeezing huge video/data down small pipes...a short search of the subject shows there's a large amount of scholarly research on the subject. I myself am ok with more current technology being put to use on our cameras if it means we get more for less.
 
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