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Posts posted by Tzedekh

  1. Now they just need to add compressed raw to the BMCC.

    (Audio levels on ALL camera models would be great too, but it seems to be asking for too much, they'll probably release a 6k camera for $500 before that happens :)  )


    I believe BMD said they were going to add compressed raw to the BMCC in a future firmware update. I wish they would license CineForm RAW. I still think they could do it very cheaply. And now that the BMCC is so much cheaper, I'd bet a lot of users would pay for the ability to record directly to CineForm RAW.

  2. We've forgotten about the Aptina-based Nikons. Now if only they could be hacked to run at the full 60p the sensor's capable of. That chip (the older one, not the newer one) is supposedly rated at about 14 stops of dynamic range, maximally. I wish CineForm would be more proactive about improving their debayering algorithm and providing solutions for recording CineForm RAW off the camera.

  3. Readout noise and maximum handling signal charge of the sensor are 1.7e-rms and 16ke-, respectively . . .


    Those are the two specs used to calculate the dynamic range:


    dynamic range, dB = 20 x log(16,000 e- ÷ 1.7 e-) = 79 dB, rounded to an integer.


    The AR1011HS's dynamic range is either 66 dB (in the flyer) or 84 dB (on the product page). If it's the latter, the sensor's somewhat larger pixels (3.4 x 3.4 μm vs. 2.86 x 2.86 μm) might, at least in part, be the reason.

  4. Can't see why they would have any interest in the cinema market. The camera side of the industry is in a race to the bottom


    It would seem so, yet Sony has gone from selling $200,000 cameras to selling ones under $30,000. Why? Because they can sell a lot more of them. What difference would it make if it cost a company a little more in R&D and manufacturing to produce a video/still hybrid that was excellent at both? They'd sell a lot more of them as a result. And 4K, once the data-transfer and heat issues are solved (and they will be), is in some ways easier to deal with, because you no longer have to deal as much with binning or line skipping, and the same OLPF is more likely to be suitable for both video and stills.

  5. Ah got you. 79db still a nice improvement on the old sensor which was rated 66db.


    I wish they'd just use stops!


    They probably never will. The dynamic range figure they quote is a computed value, not an observed one as "X stops" would imply. It's derived with the following equation:


    dynamic range in dB = 20 x log(fullwell capacity ÷ readout noise)


    As you can probably guess, this is a theoretical figure, not an observed one gotten by looking at a chart. And the "X stops" figure we toss around here is derived from that figure (i.e., by dividing by 6). That's why I'm a little suspicious of BMD's 12-stop claim for the 4K Pro camera, as the theoretical limit is 10 stops without the CMV12000's HDR tricks. Of course, the CMV could in practice be somewhat better than its specs suggest, but it's unlikely to be two stops better.

  6. The Aptina AR1011HS, likely the commercially available version of the chip in the V1, was announced last September, and I was hoping GoPro might announce a 4K camera with the sensor and CineForm RAW for significantly less than $1,000.

    Not the V1. It is 14MP so likely the V2. (This announcement was made yesterday by the way)


    I'm referring to the AR1011HS, announced in September 2012, not the AR1411HS. The AR1011HS has specs identical to the V1's. It too can do 60 fps, but only up to 3,840 x 1,920 (aka QuadHD and 4k UltraHD).


    As a side note, Image Sensors World incorrectly cited an 86-dB dynamic range (roughly 14 stops theoretically) for the AR1411HS. The correct figure is 79 db, or about 13 stops theoretically (in practice likely to be less).

  7. One of the factors limiting frame rates is the overall bandwidth that the camera can handle. Red used to rate things RedCode 28, RedCode 36, RedCode 42, etc., with the number signifiying the approximate overall data rate in megabytes per second. Assuming the sensor could handle a particular higher frame rate, either each frame had to be compressed more or the RedCode number had to increase. Of course, due to a number of factors, there was a  maximum a model could reach without overheating or otherwise failing.


    If the same is true of BMD's 4K camera, why won't they consider a lossy compression format like CineForm RAW? By reducing the data per frame, more frames per second should theoretically be possible, and at 12 bits, the CMV12000 can do 90 fps.

  8. I agree that it looks like the CMV12000, particularly when you consider BMD's specs for the 4K camera's sensor -- unless a heretofore unknown sensor is being used, only the CMV fits the specs. With its pixel pitch of 5.5 μm, a window of 3,840 x 2,160 pixels (the BMPC sensor's active area) would measure 21.12 x 11.88 mm, the same as the BMPC sensor's. Unfortunately, unless BMD has implemented at least one of the CMV's three HDR modes, it would seem that a 12-stop dynamic range would be impossible. The CMV's 60-dB DR figure translates to 10 stops, and that would be the theoretical maximum.

  9. I think Lossy DNG and Lossless DNG are too different things.


    John Brawley and the official Blackmagic website say 12bit lossless DNG. It is still compressed but it is lossless like raw not lossy like JPEG.


    Here's John's tweet just now - https://twitter.com/brawlster/status/321411372296577026


    Just to be clear: raw can be lossy or lossless. And "lossless" compression can mean visually lossless or, more precisely, mathematically lossless. Compressed CinemaDNG is the latter, but Adobe has said that future versions of the spec might also include lossy compression. If GoPro doesn't jump in and strike a mutually agreeable deal for CineForm RAW before the cameras are released, they will look foolish.

  10. Yes the big Japanese makers will have to respond -


    Doing nothing is a response. Sony's cheapest 4K camera, the FS700, will cost at least three times as much when upgraded to 4K. Canon inexplicably seems enamored with 8-bit codecs, except for their raw option, which is only 10-bit. And Panasonic's only 4K camera is a small-sensor prosumer model. If and when they release their 4K VariCam, expect it to cost between the Sony F5 and F55 and have no raw option.

  11. Problem is, we don't know anything about the sensor in the 4K camera, especially dynamic range. I have an unsettling suspicion that it's the CMOSIS CMV12000, which gets 10 stops at most without HDR. It has three HDR modes, none of which is particularly suited for film/video work. At least the BAE CIS2051 had dual (high-gain and no-gain) readouts that were merged to yield 13+ stops of dynamic range (and effectively 16-bit A-D conversion). The CMV12000 is an enormously expensive chip at this price point -- its per-unit cost of something close to $1,500 amounts to more than a third of the camera's purchase price, not just its cost to manufacture.

  12. This is a good device. All I say, forgive my bluntness, is that it seduces you to show off, that you do things without need. Because, look at the history of film, too prominent traveling shots are distracting, they don't help the story.


    Well, with regard to what's gratuitous -- whether traveling shots or anything else -- that's a matter of opinion and preference. Steadicam was overused in the beginning, but its use moderated.


    AND EDIT: In most situations, a tripod or a shoulder rig will do. For most situations, they would be indeed more appropriate. How many percent? You 'll see, with a MoVI, there will be less cuts, the device changes the approach to the scene.


    But for some of the shots where a tripod or shoulder rig has been traditionally been used, MōVI will be a better choice: maybe less time setting up a shot where a tripod would otherwise be used, and probably less-shaky footage where a shoulder mount would be used (BTW, I generally really hate most handheld footage, especially the shaky "raw" aesthetic popularized by NYPD Blue and used ad nauseaum since).


    Brace yourself for an example of nauseating camera work. It's enough to watch the first five minutes, perhaps then you'll see what is looming once these MoVIs get to the hands of the vimeots or youtubers:


    Maybe the well-heeled or at least well-funded vimeots and youtubers, but until there are sub-$1,000 MōVI knockoffs, this is otherwise doubtful.

  13. This Mōvi (at a price of, say, 2000 bucks) would lead to dramaturgically unmotivated steady shots in heaps. . . .
    None of the steady shots would change the quality of low budget films at all.

    "Unmotivated steady shots"? What's next? An epidemic of films with shots that are inexplicably exposed, focused, and framed properly? Oh, the horror!
  14. The main issue with both Canon and Panasonic had always been tryoing to balance the Photographic and the Video capability upon the hardwre.

    That shouldn't be as much of an issue with 4K video. Optimize the OLPF for still and use the whole sensor at video speeds, with the extra pixels devoted to oversampling. The technology should be there to do that -- or would be, if Panasonic (or any other manufacturer, for that matter) had the will.
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