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Sony A7r II new 4K FF beast with 5 axis stabilizer
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  • I don't understand some of the sensor/crop things so I hope you don't mind asking me a question. On several sites I now read about "Pixel binning" and this camera's sensor because of it's high megapixels not being optimal for video recording. Could someone please explain this to me in simple words?

  • We first saw the effects of pixel binning on the Canon 5D MkII. It means that the sensor can't be read fast enough to do continuous video if all photocells are read, so some lines of them are skipped and later interpolated to get an image with the full sensor size. This can lead to massive aliasing aka moiré.

    Even if cameras became much faster by today, when reading the full area of all those megapixels (actually photocells) in the A7RII, it needs pixel binning. But if you crop the sensor area to APS-C (actually the same size as S-35mm film and all the high-end digital cameras like Arri Alexa, F5/55 etc.) according to my information it can read that area without pixel binning.

    So, it's no big thing IMHO, still a great combination of a high-res stills camera and a 4K video camera.

  • @olli6 The a7rII features a 42MP sensor but 4K video is roughly only 8MP. All that extra data has to go somewhere: You can get the best image and process and scale all 42MP down to 8MP on the fly at 30fps (which takes a lot of expensive processing power), or you have to throw some of the data away and average groups of pixels to reduce the data load but that can hurt image quality.

    Sony have taken a smart approach and included a crop mode that reduces the amount of total pixels that need to be read. In theory this should help the camera process those pixels more accurately and give better video quality.

  • ah, ok, thanks for the explanations guys, so virtually most photo cameras who also have a video function have this "problem"

  • Yep, with the exception of the Sony A7S, which can read the full sensor without binning (only 12 mpx). If recorded externally, it challenges a Red Scarlet – in resolution, but not DR or gradeability.

    If the A7RII can read all pixels in crop mode, I expect it to look very good too.

  • this is all very exciting but for once I may not "early adobt", it's a new sensor, a new era but why jump on it now when I already have great cameras (GH4)...I guess I will wait for a A7s Mark II...

  • Line skipping is not the same as pixel binning.

  • Yes, admitted, but the artifacts are similar, and not all manufacturers tell us what they do…

  • No. Line skipping causes false color, spatial aliasing, and reduced noise performance. Pixel binning just means the read-out has less resolution, which usually translates to an undersampled output image.

  • So I'd say Sony is line skipping when things get tight, since 720p slo-mo from A7S looks awful, while UHD from full sensor is clean.

  • gosh, this camera looks amazing - technology is outpacing my ability to think

  • " At the end of the video, you'll see that, unfortunately, all the AF modes are not available with 3rd party glass on the a7R II. Therefore, it's difficult (if not impossible) to specify what it is you want the camera to focus on, which makes this continuous AF mode of potentially limited value. "

    Shit !

  • Some samples including to ISO 25,600 with preview firmware.

    http://piebbs.pconline.com.cn/topic-136927.html

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    985 x 1477 - 306K
  • Thanks for the RAW sample, my question is how to open it? Lightroom 5.7.1 (my latest built) does not support it, neither does Adobe RAW - DNG converter from April 2015.

  • I heard Capture One 8.3.1 opens them.