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02-05-2014, 09:31 AM   #106
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QuoteOriginally posted by kadajawi Quote
But isn't the only way to get actual RAW files to get access to the sensor? Meaning you can do stuff like ProRes with those recorders, but actual CineDNG, where you are free to chose the white balance etc... I don't think so.
For DNG raw, yes, but 'raw' and 'DNG' aren't the same thing...

'Raw', is the full dynamic range and detail from the sensor. That can be sent to SD card, or out through the HDMI port.
On the SD card, Compressed CinemaDNG is the file format to store those raw frames.

On an external recorder you'd be most likely to record in ProRes or DNxHD, but there's no reason why you can't be doing so in a 'film' profile, instead of a 'video' profile (that sticks to the Rec709 specs.)

02-05-2014, 11:32 AM   #107
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QuoteOriginally posted by PiDicus Rex Quote
For DNG raw, yes, but 'raw' and 'DNG' aren't the same thing...

'Raw', is the full dynamic range and detail from the sensor. That can be sent to SD card, or out through the HDMI port.
On the SD card, Compressed CinemaDNG is the file format to store those raw frames.

On an external recorder you'd be most likely to record in ProRes or DNxHD, but there's no reason why you can't be doing so in a 'film' profile, instead of a 'video' profile (that sticks to the Rec709 specs.)
Not quite sure I get you.


DNG is a way to pack RAW data. The 5D Mk III RAW video files should if I'm not mistaken be fully RAW. Lossless. DNG also supports lossy RAW data, but even lossy (at least as produced by Lightroom) it should have (almost) the full dynamic range and detail, certainly more than with a JPEG. It can be edited the same way. Only if you push it very far, say overexpose by 5 EV in Lightroom, then you'll notice the differences. Not sure how exactly they do it. But Cinema DNG does not necessarily have to be lossy DNG. For Pentax it would most likely be easiest to do pure RAW DNG video. Otherwise they'd have to find a way to encode lossy DNG, which the camera doesn't support. And IO isn't as much of a problem as with say the BMPCC, as the K-3 has 2 slots.


It seems like 35 MB/s is the max the K-3 can do with one slot. (https://www.pentaxforums.com/forums/172-pentax-k-3/241929-fastest-sdhc-k-3-c...ml#post2616093) Pentax K-3 Review - Performance and Burst Mode - PentaxForums.com They say 2-3 fps for JPEGs after the buffer is full, which with 11-13 MB per JPEG should be somewhere around 30 MB/s.


Ok... so according to EOSHD 1080p RAW video at 24 or 25 fps is around 83 MB/s. At that point we are screwed it seems, evene when using 2 SD cards. Now if the K-3 processor is fast enough, it might be possible to utilize the lossless compressed DNG format. Then again that might be what is happening in the Canons in the first place...


Also, if someone is wondering why RAW:
http://www.eoshd.com/content/11395/real-difference-normal-dslr-video-5d-mark-iii-raw-video


To be honest the amount of data is too much for me. I couldn't handle it... Unless I'm working on a serious project I wouldn't use RAW.
02-05-2014, 03:11 PM   #108
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QuoteOriginally posted by kadajawi Quote
11-13 MB per JPEG should be somewhere around 30 MB/s.
Ok... so according to EOSHD 1080p RAW video at 24 or 25 fps is around 83 MB/s. At that point we are screwed it seems,
That roughly jives w/ what people measured. The K-3 only can really use 45MB/sec SD cards for writing...90MB/sec cards make a marginal difference.

The 5D can do those speeds because it uses CF which is faster than SD cards until we get UHS-3 (3 channel) SD cards. Current ones are only UHS-1.

Panasonic demo'd their GH4K w/ prototype UHS-3 SD cards, so they don't even exist in production yet...
02-05-2014, 05:15 PM   #109
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Would those faster cards be faster in the K-3?

02-05-2014, 05:39 PM   #110
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Most likely I hope a firmware update will accommodate these faster cards on the K-3!
02-05-2014, 07:00 PM   #111
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QuoteOriginally posted by kadajawi Quote
Would those faster cards be faster in the K-3?
You mean the UHS-3?

Nope. 3 channels = hardware changes...

The chips today probably don't even know how to talk to the cards...
02-05-2014, 08:37 PM   #112
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Yes. That sucks. So this probably means no RAW, unless Pentax finds a way to increase speed, make each frame smaller (and that consistently... Or at least so that there is no risk of having the video stopped due to a full buffer). Reducing the resolution would work, but it might not be "appropriate" for a manufacturer to offer some weird crooked resolution. Going to 12 bit could also help, but we'd rather have 14.


@kenyee: I've searched for what people have measured. I neither have a K-3 at my disposal, nor do I have those fast SD cards.


Now one final possibility may be to use SSDs to write to. But I think somewhere it was mentioned that the USB 3.0 port is in reality more like a USB 2.0 port painted blue... the speed just isn't there (or they have used very slow SD controllers).
02-07-2014, 06:05 AM   #113
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QuoteOriginally posted by kadajawi Quote
So this probably means no RAW, unless Pentax finds a way to increase speed,
This is one of the reasons I've been trying to find out what sort of SD Controller is in the BMD-Pocket Cine camera - I think it's probably UHS-1, and not the 3 channel variant like the GH-4 has (which launched today, and the specs are impressive).

If BMD can do Compressed CinemaDNG on a 'normal' UHS-1 controller, everyone else should be able to for HD as well.

The GH-4 is claiming that 4K @ 100Mbit/s needs a 30Mbyte/s card as minimum.

02-07-2014, 08:06 AM   #114
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Hm. According to Blackmagic Design the Pocket Camera uses lossless CinemaDNG compression. So we are not talking about enhanced JPEG in a DNG wrapper here, it's the real deal that is coming out of the K-5 and K-3 anyway. With ProRes 422 it is 220 Mbps. For CinemaDNG you can expect around 2-2.4 MB per frame with that camera, but we're talking about 12 bit files only. 14 will be a bit bigger I suppose. So 60 MB/s it is. 64 GB card will get you around 20 minutes at 24 fps. The SD controller in the BMD will have to be faster than what is in the K-3, however since the K-3 can do around 30-35 MB/s it would be enough. I think the reason why the hacked Canons use a much higher bitrate is either because the RAW files are 14 bit (mh... does it make such a big difference?) or because the files are not compressed at all. I think it is a combination of both, but mostly the latter. My 6 MP Pentax without any compression did 10 MB per shot, compressed in Lightroom to DNG it was around 5 MB on average. The K-5 does around 25 MB per shot (already compressed), Lightroom can get it down to maybe 20 MB, simply because the compression in camera is not that sophisticated. If we factor in that at lower resolutions there is usually less compression possible, then I think we should be able to get down to do-able frame sizes. Just forget about any high frame rates, and two cards are absolutely necessary. Clearly, handling the files won't be very easy, which for a manufacturer supported function is problematic.

And now I'll go check out the GH-4.
02-07-2014, 10:20 AM   #115
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QuoteOriginally posted by kadajawi Quote
.......a much higher bitrate is either because the RAW files are 14 bit (mh... does it make such a big difference?) or because the files are not compressed at all.
...
For uncompressed data it is proportional, that is a 14 bit per pixel image will occupy about 16% more space than a 12 bit image.

With lossless compression the difference between 12 and 14 bit will usually be greater because the extra bits will have higher entropy and be less compressible as it were.
02-07-2014, 09:28 PM   #116
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QuoteOriginally posted by kadajawi Quote
The SD controller in the BMD will have to be faster than what is in the K-3, however since the K-3 can do around 30-35 MB/s it would be enough.
The controller should be the same speed IMHO - the controller performance is part of the SDXC specifications, which is what includes the UHS-1 specs.
Yes, there are cards that can do more then the specifications, but the controller hardware still has to be handle any card that matches the SDXC standards.

QuoteOriginally posted by kadajawi Quote
According to Blackmagic Design the Pocket Camera uses lossless CinemaDNG compression. So we are not talking about enhanced JPEG in a DNG wrapper here,
Yeah, we are, the Jpeg variety is the Lossless variety.

http://www.cinema-dng.com/wp-content/uploads/2013/06/CinemaDNG_Format_Specification_v1_1.pdf

CinemaDNG
02-07-2014, 10:37 PM - 1 Like   #117
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@lister6520: Ah, thanks. Makes sense.

@PiDicus Rex: Ah ok. Yes, lossless JPEG. When you said JPEG I assumed it was the regular, lossy JPEG we are used to, which is also supported by DNG (but in that version of the paper (which is already quite old) it is only being considered, not supported yet).
Lossy DNG – too early? – Lightroom Solutions – John Beardsworth

Last edited by kadajawi; 02-07-2014 at 10:42 PM.
02-13-2014, 11:42 PM   #118
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EOSHD just reviewed the Nikon D5300... which... has the same sensor as the K-3? If the D5300 uses the same sensor as the D5200, and the K-3 sensor is indeed the Toshiba sensor in the D5200. Image quality is really good. No moire, which plagues my K-5. Great low light performance. The D5300 should use a similar processor to the K-3, though maybe a slightly enhanced, newer version. It shoots at up to 38 Mbit, rather than 20-24 that the K-3 does, but that may be fixed in the firmware.


Anyway, it's a good, fun read that shows that Nikon, just like Pentax, f***ed up. The camera has all the right ingredients, and with a few firmware fixes it could be much better. They just couldn't be bothered to do something good, it seems. As long as the spec sheet looks fine they are happy... actual ergonomics, real life use, the engineers didn't care. Just like the K-3.


I still think that if Pentax were to invest a bit in the firmware, or better yet were to work with Magic Lantern, maybe give them, if interested, access to the source code, to the technical details and give them some assistance then the K-3 could be a filmmakers (budget) dream. The K mount would be a bit of an issue, cause it is rather adapter unfriendly, unlike those mFT cameras, but otherwise...
02-14-2014, 11:17 AM   #119
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QuoteOriginally posted by kadajawi Quote
The K mount would be a bit of an issue, cause it is rather adapter unfriendly, unlike those mFT cameras, but otherwise...
Ahh Grasshopper, much to teach of shopping there is....

So far, I've found decent secondhand K-mount lenses have a much lower price premium on them compared to similar specification EF and Nikon glass.

Now, given the sheer volume of Sheeple who buy Canon ( because, y'know, everyone has Canon,.. ), if you work with people who insist on shooting on any Canon with an APS-c sensor, a K-mount to EF-Mount adapter ring is a useful choice - $10(AU) gets you a ring that will do the job nicely.

Because the Flange-Sensor distance is longer on the K-mount, something like 3mm longer then the EF mount, and almost double the length of the NEX and MFT mounts, you can always stick the K glass on other cameras, but not be able to go the other way.

This also means, if you combine a FF K-mount Lens, with an EF ring, and a Metabones 'SpeedBooster' EF to MFT mount, you can get a truckload of light on to the sensor of a BMD-CC,.. Iff they ever get the MFT version out to customers...

And of course, as a full manual lens, with a proper Iris ring, a nice classic K-mount lens gives a 'look' that none of the Canon glass imitates.


I've had my Pentax and Sigma lenses on a 7D with good results, and on a 550D with Magic Lantern installed, and gotten some beautiful and cinematic looking footage.
With the Cinestyle profiles and ML controlling the 550D camera, and letting us ramp up the data rate to the maximum we could get out of the SD cards, and with my USB/DMX controller rig to match the lights to our chosen aperture/ISO, we were able to shoot dark moody scenes, that we just wouldn't have gotten with the available Canon Lenses for that short film.

Last edited by PiDicus Rex; 02-14-2014 at 11:42 AM.
02-14-2014, 11:24 AM   #120
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That's what I meant. A K mount camera will only ever take K mount lenses (or medium format ones...). A EF mount camera is more flexible. And a mFT mount will take anything. Basically what I wanted to say was that if Pentax gets the firmware right for video use, squeezing the most out of the hardware as possible, giving as many video centric features as they can, it would be great and could draw in people coming from other systems. The only issue is that the K mount is kind of limiting. What if someone has Canon glass, but wants to use it on a K-3?
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