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Would an AF100 benefit from an external HD-SDI recorder?

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    Would an AF100 benefit from an external HD-SDI recorder?

    Since the AF100 captures the image from a 1920*1080 area, there are only 960*540 blue and red pixels, and 960*1080 green pixels. The luma resolution is 1920*1080 but the color resolution is obviously lower. The AVCHD codec with the 4:2:0 color space it's probably enough for recording the image.
    Would the camera benefit from 4:2:2 recording?

    #2
    Yes, as sensor resolution is not 1920x1080 :-)
    It is much higher, most probably around 16Mp (with total 18Mp count).

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      #3
      Yes, I'm planing on using: Zeiss PL Lens > AF100 > CineDeckExtreme @ 2k. Things are getting interesting.

      Cheers
      "Of all the things I've lost, I miss my mind the most"

      Comment


        #4
        i believe the 2k option will only work if the camera is putting out 2k for you, and requires dual link/3g sdi. which i don't think the af100 gives, simply 8/10 bit HD SDI, not a confirmed spec yet, at 1080p. but cineform recording at 1080p is probably one of the, if not the best visually lossless codecs out there.

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          #5
          what is the difference between 4:2:2 and 10bit, 12bit etc? Can something be 8bit but still have 4:2:0 colorspace? If it was already confirmed the af100 will be 8bit, how will the external recorder benefit it at all?

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            #6
            read this and this will explain a lot to you

            http://blogs.adobe.com/VideoRoad/201...rocessing.html


            abridged version, the higher the bit depth, the more color information and physical amount of detail the codec can hold. Allows for mathematically a higher range in graduation of color too so you can really make fine adjustments in the color grade.

            also gives relevant picture information that is really important for VFX work, especially for keying, compositing and motion tracking.

            on top of that the higher the bit depth the more resistant it is to loss in quality on transcoding, and a VFX shot will go through several transcodes before it's in final form and you have to try to maintain the highest quality possible by starting at the highest quality possible.

            10 bit would allow for a lot of these things, including a 4:2:2 chroma subsampling, you can have 8 bit 4:2:2 but it's not as versatile as the 10 bit, the difference is huge if you look at the site. 12 bit can mean no sub sampling at all and you can retain your RGB values, meaning the full color spectrum of the image. Or 4:4:4

            the gold right now is going to be 16 bit in the coming years. It is mathematically lossless in most senses and can withstand the most vigorous of DI processes and allow for the most calculated of manipulation and image fidelity. Anything on top of that might be considered overkill for acquisition, but you still work in a higher bit depth space for mathematical wiggle room and assuring you don't lose anything in the process.

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              #7
              Originally posted by xmephestox View Post
              i believe the 2k option will only work if the camera is putting out 2k for you, and requires dual link/3g sdi. which i don't think the af100 gives, simply 8/10 bit HD SDI, not a confirmed spec yet, at 1080p. but cineform recording at 1080p is probably one of the, if not the best visually lossless codecs out there.
              Good point. I guess its: Zeiss > AF100 > CineDeckExtreme @ 1080p. I think it should be a great match. Thanks.
              "Of all the things I've lost, I miss my mind the most"

              Comment


                #8
                Originally posted by xmephestox View Post
                read this and this will explain a lot to you

                http://blogs.adobe.com/VideoRoad/201...rocessing.html


                abridged version, the higher the bit depth, the more color information and physical amount of detail the codec can hold. Allows for mathematically a higher range in graduation of color too so you can really make fine adjustments in the color grade.

                also gives relevant picture information that is really important for VFX work, especially for keying, compositing and motion tracking.

                on top of that the higher the bit depth the more resistant it is to loss in quality on transcoding, and a VFX shot will go through several transcodes before it's in final form and you have to try to maintain the highest quality possible by starting at the highest quality possible.

                10 bit would allow for a lot of these things, including a 4:2:2 chroma subsampling, you can have 8 bit 4:2:2 but it's not as versatile as the 10 bit, the difference is huge if you look at the site. 12 bit can mean no sub sampling at all and you can retain your RGB values, meaning the full color spectrum of the image. Or 4:4:4

                the gold right now is going to be 16 bit in the coming years. It is mathematically lossless in most senses and can withstand the most vigorous of DI processes and allow for the most calculated of manipulation and image fidelity. Anything on top of that might be considered overkill for acquisition, but you still work in a higher bit depth space for mathematical wiggle room and assuring you don't lose anything in the process.
                thanks I'll look at the link.

                So Red One is 12bit I believe, and aF100 is confirmed will stay at the weak 8bit?
                No possibility of getting even 10bit out of AF100 at all?

                Comment


                  #9
                  it's not a finalized spec yet, which is why everybody including myself keeps nagging for it. Acquisition is one part, and than putting it through the vigors of post is another. 8 bit is very limited and you can see the difference in 10 bit alone, you get almost 4x the amount of color information. That could be a major difference in saving a shot from exposure issues, among other things.

                  RED is 12 bit, it's a RGB source, the issue now is their compression, which is at the moment around 8:1 (somewhere around there) next gen they are claiming 16 bit, with the opportunity to have a 2:1 compression method which is mathematically lossless.

                  Comment


                    #10
                    xmephestox but I thought that Jan already confirmed that the HD-SDI will be 100% 8bit. So when you said not a finalized spec yet, are you referring to something else or do you think their confirmation is not finalized?

                    Comment


                      #11
                      possibly hopeful thinking, but it's said that there is still 30% more to go on the camera. she's merely been saying the prototype model (there is no production model, they are all prototypes) is 8 bit. thus there is always the opportunity for them to change it in december. and I"m earnestly hoping they will do this final change before shipping with enough out cry for it. They've listened before, they might listen again.

                      Plus they are advertising using their SDI avc intra portable recorder with the camera if you want higher quality recording. But with a 8 bit SDI, you are still taking a big hit, you do gain by still recording that signal in 10 bit, but if they are advertising a 10 bit acquisition in some way or fashion, shouldn't they actually make it 10 bit?

                      Comment


                        #12
                        AF100 is 8-bit. And when you say "weak" 8-bit, can I please point out what else is "weak" 8-bit?
                        Sony F900
                        VariCam
                        DVCPRO-HD
                        HDCAM
                        Sony PDW800 with XDCAM-MPEG422 at 50 megabits
                        Canon XF300/XF305 with MPEG2 at 50 megabits
                        280mbits NanoFlash

                        Basically every HD camcorder on the market is 8-bits. If you want 10 bits, there's only one place to go - AVC-Intra.

                        So, while it'd be a bonus and a nice bonus to have 10-bit output, it hasn't changed my opinion at all. If 8-bit formats like DVCPRO-HD and HDCAM and XDCAM-MPEG422 are good enough to be certified for unlimited acquisition, editing, and mastering by DiscoveryHD, why all of a sudden is everyone saying 8-bit is so weak?

                        Why not give it a chance before writing its epitaph? Star Wars Episode II was shot on 8-bit for cryin' out loud.

                        Yes, 10-bit is vastly preferable. But it's not like 8-bit is all of a sudden "bad"...
                        ..
                        The AU-EVA1 Book - The DVX200 Book - The UX180 & UX90 Book - Lighting For Film & TV - Sound For Film & TV

                        Comment


                          #13
                          so with one of those after market recorders that you guys are talking about, is it possible to record AF100 at 8 bit but with 4:2:2 and/or 50megabits?

                          Comment


                            #14
                            Uhhh.....my question was still not answered....
                            The VDSLRs get the image either by skipping pixels or using pixel-binning.
                            So there are only 1920*1080 green, blue and red pixels.
                            A camera like Sony EX1 has three sensors:there are 1920*1080 pixels for each color. The XDCAM codec records in 4:2:0 so the color recorded is at 960*540.
                            But if you capture the image through the HDSDI you get 4:2:2 footage and 960*1080 color resolution. A camera like this benefits from external recording in 4:2:2 color space.
                            But would the AF100 benefit from this?

                            Comment


                              #15
                              Originally posted by xmephestox View Post
                              thus there is always the opportunity for them to change it in december. and I"m earnestly hoping they will do this final change before shipping with enough out cry for it. They've listened before, they might listen again.
                              I agree with this, perhaps there's the possibility they'll make it 10. If Jan's saying "it's 8-bit and it's not gonna change" then we'll have to take her at her word. She is, after all, the US Product Line Manager for the product. If instead she was saying "today it's 8-bit, and it's still under review" then maybe there's hope. In what I saw her say, I figured it's 8-bit and is gonna stay that way.

                              Plus they are advertising using their SDI avc intra portable recorder with the camera if you want higher quality recording. But with a 8 bit SDI, you are still taking a big hit, you do gain by still recording that signal in 10 bit, but if they are advertising a 10 bit acquisition in some way or fashion, shouldn't they actually make it 10 bit?
                              It would be ideal, yes. I would presume (assuming here, of course) that they will have the ability to do some manner of "chroma smoothing" on the 8-bit as it gets recorded to 10, and that should definitely help in pushing/pulling in post, so there still would be some benefit (just like you can chroma-smooth 4:1:1 into 4:2:2 and, while it's not as good as camera-original 4:2:2, it's still better than nothing).

                              And there are also benefits to recording 1920x1080 uncompressed 4:2:2 as AVC-Intra, whether you're using 8-bit or 10-bit, so there are still plenty of reasons for people to consider whether they would want to use the HPG20. It's just that one of the potential benefits (getting full 10-bit color) won't be realized. But you'll still be getting AVC-Intra compression and 4:2:2 and those are big benefits.
                              ..
                              The AU-EVA1 Book - The DVX200 Book - The UX180 & UX90 Book - Lighting For Film & TV - Sound For Film & TV

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