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Portable Capture System
I’m designing a prototype of a portable capture system. I would like information and feedback from professionals as to the practical viability of such a system.
Questions I have are…
1. I’ve seen footage from latest high-end CMOS based cameras using long GOP compression….seems like fast-moving parts of image within frame lose clarity…..even when using fast shutter speed…Is this due to high compression within camera or inherent problem with responsiveness of CMOS sensors….i.e., would this problem dissapear if one were able to capture uncompressed 4:2:2 8 or 10-bit via HDMI / HDI-SDI…?
2. Downstream from capture, would professionals working with existing editing hardware/software be able to easily incorporate the uncompressed footage into their workflow….?
I’d be grateful for your input..
Brian Jacobs
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20 Replies
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Brian,
No “high end” camera system uses long GOP recording compressions, only consumer and “pro-sumer” units do.
The best compression scheme available at the moment is the AVC-I implementation that Panasonic is offering on their high end cameras like the “3000”. What distinguishes this format is that it’s full 10bit, does not horizontal downrez (full 1920 raster) and uses half the bandwidth of their previous best format (DVCPRO100) at equal quality, or offers double the quality (equal to D5) at the same bandwidth.
Don’t worry about the post production implementation as the players in this arena have to respond to whatever is become popular, especially as it catches on in volume.
JS
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Thanks for your response…
I’m actually talking about pro-sumer cameras (sub 10,000 dollars…?) like Sony PMW-EX1 or EX3 etc….I asked these questions of Don Greening on another CC forum and he advised me to post it to the Sony Cine-Alta forum…..
I’m talking about overcoming the capture and storage limitations of the pro-sumer (sub 10,000) cameras by providing a truly portable solution capable of 8-bit or 10-bit 4:2:2 capture in either AVI or MOV format….
Brian
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[john sharaf] “No “high end” camera system uses long GOP recording compressions, only consumer and “pro-sumer” units do.”
I hate when people use terminology like this.
I wouldn’t call XDCAM 335, 355 or the eventually arriving 700 “pro summer” and they’re all Long GOP to XDCAM disc.
The XDCAM EX series is full 1920×1080 sensors and is Long GOP to SxS cards. HD-SDI out is 4:2:2 10 bit Uncompressed and never touches the XDCAM compression so that’s not Long GOP at all.The above cameras certainly serve ENG and Corporate video market and, in some cases, lower budget cable and broadcast TV.
AVC-I and DVCPro100 have their own set of issues otherwise people wouldn’t be using the above Sony Cameras. While these two codecs are not Long GOP, they certainly are compressed and certainly have various workflow issues. Codec and Long GOP are only one factor to consider when using a camera and creating an efficient production/post production workflow.
The same can be said for CMOS vs CCD. RED is CMOS for example. Certainly CMOS is in less expensive cameras compared to their competitors (Even RED is a less expensive competitor against higher end cameras). In the “real world” cost is a factor too.
There’s also chip size. Some find the EX’s 1/2″ chip and 1920×1080 sensor size worth the sacrifice of CMOS and Long GOP because of quality & price combination. They are certainly used in Professional environments and, when handled with an understanding of the limitations, excellent professional quality.
I wound not call a Sony F355 “prosumer” even though it’s Long GOP but that’s just me. Nor would the 700 be (when it comes out). I wouldn’t call RED “prosumer” either even though it’s using CMOS. I don’t consider the EX “prosumer” either. I don’t think one would mistake them for a Viper or F35 either but not every professional production calls for those.
I certainly wouldn’t call Long GOP “prosumer” and DVCPro100 professional. They both have problems (and advantages) as codecs.
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I believe Convergent Design is working in this area so you’d have to think about what they’re doing and how you can make yours better/different.
https://www.convergent-design.com/index.html
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I’d agree with that 100% Nothing “Pro-sumer” about the XDCam series. Very inflammatory comments for a Sony forum.
Steve Connor
Adrenalin TelevisionHave you tried “Search Posts”? Enlightenment may be there.
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[Craig Seeman] “I believe Convergent Design is working in this area so you’d have to think about what they’re doing and how you can make yours better/different. “
Thanks, Craig. In previous dialogue with Brian I had eluded to Convergent Design’s products, but obviously not strongly enough. I think that company’s Flash XDR device is just what Brian is looking for.
– Don
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Craig, your comments noted…thanks…I’m always at a loss myself as to what constitutes ‘prosumer’ and what ‘professional’ – I’ve just drawn an arbitrary line at 10,000 dollars and I’m looking at people using sub 10,000 dollar cameras…..
as my father said ‘confusion is the one guest that never refuses an invitation’….
Basically, what I’m designing is something that will take the HDMI or HD/SDI output from a HD (1920 x 1080p) sub 10,000 dollar camera such as the Sony EX1 or EX3 and capture to a hard disk array, sort of like some Convergent Design products, but in a form that will incorporate a complete wearable solution (as a backpack) and allow the cameraman complete freedom of movement, virtually unlimited hours of shooting (say 8 hours a day). Very ambitious. I was a computer geek before I turned to video, so I know I can do it, using existing components….question is ‘Is it worth it…?’ ….question 2 has been answered…thanks…question 1 remains…….
1. CMOS based cameras such as Sony EX1 – fast moving objects (tennis game, cars on a highway) get blurred, even when shooting at fast shutter speeds…..my question is this – Is this blurring due to compression within camera or an inherent problem with responsiveness of CMOS sensors….? this has direct relevance inasmuch as if it is a problem with responsiveness of CMOS sensors, then it won’t be solved by bypassing the cameras compression….however, if it is not due to the sensors, but due to the compression, then it should be solved by capturing uncompressed direct from HD-SDI port……..?
Brian…
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I have to say I disagree with this statement, we primarily use EX1’s for shooting aircraft at air displays and we get no issues with blurring (except when I get the focus wrong!) and some of these are travelling at very high speeds.
Steve Connor
Adrenalin TelevisionHave you tried “Search Posts”? Enlightenment may be there.
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Great, thanks for that info Steve….very much appreciated…
Would there then, in your opinion, be no advantage as far as image clarity goes to being able to capture uncompressed, as opposed to using the cameras inherent compression…..?
Are you shooting full 1920 x 1080p…..?
Any difference in clarity of fast-moving objects shooting 1080p vs 720p….?
Any difference in clarity between objects held in frame (ex panning with the aircraft) as opposed to a stationary frame with the aircraft moving from one side of the frame to the other (assuming aircraft size in frame is about 1/8th entire frame….?
I understand that Sony advises using 720p rather than 1080p to get clarity at speed…..is this correct….why……?
Brian….
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Don,
I know about Convergent Designs products and specifically the Flash XDR…..wasn’t ignoring your pointer in that direction…..
I’m interested in exploring the advantages of working uncompressed.
Wafian HR-F1 is closer to what I’ve been working on…..with this major difference – the Wafian is a big box and limits camera movement unless you have someone to carry it around with you….. whereas what I’m after is a wearable system that allows better camera movement……
I can make a testing prototype in two weeks with my own money (I’ve been working on the design for a while) – the question is – is it worth doing………? or are the existing codecs employed by the sub 10,000 dollar cameras delivering enough quality……i.e. is there any real-world advantage in being able to bypass camera internal compression and get AVI or MOV uncompressed files…….that’s really the question I’m trying to get a clear answer to, from working professionals such as yourself…..
I appreciate your continued input on this issue….
Brian.
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