4:4:4 12-bit Uncompressed DVX100

[Obin Olson]

waiting for that image post!! shoot some stuff with LOTS of colors in it for the tests/image grabs! need server space? I can give you some!

[Adam Burtle]

So Juan.. what is the answer then..

either the PAL DVX doesnt share chips with the NTSC one..

the PAL camera somehow upconverts the raw image to the pal 576 standard..

or you are capturing a "raw" signal that has somehow already been downsized from a 576+ signal?

I 100% believe you when you say that is the size of the frames you've captured, I just dont understand how that can be, when pal cameras do 576?

::very excited to see some frame grabs:: ..or even some short video. If you need somewhere to host the video or frames (regardless of file size), I can handle that for you.. just drop me an email (adam@adamgeek.com)

[Juan P. Pertierra]

Adam:

I am 100% that what I'm getting is the raw CCD size.(unless the service manual I have is part of some evil scheme by panasonic).

However, I think i've found evidence that the CCD's are indeed different between the NTSC and PAL versions, other than the frame size. The CCD sensors do not seem to be square, but rather have the NTSC aspect ratio...the raw frames of resolution charts having circles in them come out as slight ellipses, which are turned into circles when the NTSC pixel aspect ratio is applied. The difference is small, so I didn't see it until I used a rez chart.

[Carlos Dias Vega]

I am very excited about this thread. I just read it all, but some things aren't clear to me. Maybe you guys could explain a bit.

So actually the quality of a raw footage taken by a Panasonic DVX100 or a smilar camera is great, but because the camera saves the shot on the DV format is loses quality. So now we are trying to do something so we can direct store the raw format on for example on a HD without losing quality?

But then, if so.. when I search on google there are many products (especially the brand matrox pops up everwhere) which will transfer a footage from a mini DV to the PC.. why not use these then?

sorry, kinda new to this :)

[Juan P. Pertierra]

Carlos,

Because those products store the compressed DV stream that comes out of the camera, which is the exact same thing that is saved to tape.

Manufacturers do NOT allow you to access any other data stream other than the compressed DV stream that is recorded to tape, or the analog output which is horrible.

BTW, sorry for the lack of updates, right after i got done with my 3 tests i left for spring break to visit my family since i haven't seen them in a while...will get back to work soon...it is almost done.

Juan

[Filip Kovcin]

i'm very curious to see some examples too. this threas is breathtaking! i thought that i already found some fantastic threads here on dv i community, but this one is just unbeleivable!

juan,

does this mean - in your opinion, that i.e. beta sp, or digibeta can give us even more superior pictures? if dvx panasonic is cappable to "see" more then it "can" record - does it mean that broadcast cameras can "see" in "raw mode" more than just pal/ntsc, say - something closer to hd?

just curious

filip

[Juan P. Pertierra]

Fillip:

The output of this experiment yields 4:4:4 uncompressed color in ANY camera. however, there is one thing that you do get with a more expensive camera: better CCD's. This translates into larger frame sizes(i.e. closer to HD) and less noise...also with larger CCD sizes you get a shallower depth of field that better mimics film.

So yes, you do get advantages of doing this procedure on a better camera, however, i think it is up in the air how good actual DigiBeta(4:2:2 3:1 compression) will look compared to the raw DVX output.

Juan

[Rob Hester]

so, do you think your technique could be adapted to other cameras then? any chance of releasing pictures showing us the inner workings for DIY'ers?

[Peter Moore]

Not to rain on anyone's parade, but if you're gonna go through all this trouble, why don't you just buy the CCDs, circuit boards, lens, etc., and design your own camera? You could probably do a better job than Panasonic, and you'd have exactly the features you want.

[Juan P. Pertierra]

Peter,

As soon as you find a source for state of the art CCD's such that I can buy a small amount for less than $10,000 a piece, i'll happily do it.

Good Luck! :)
Juan

[Peter Moore]

:)

My understanding is you can get them via the astro-photography community, which frequently mod's their telescopes with CCDs and cameras. They are expensive, but most are much under $10,000.

[Juan P. Pertierra]

Peter,

I am an astrophotographer myself, and unless i'm mistaken somewhere, there is a huge difference between a broadcast video CCD and the CCD's commonly used for astrophotography. In fact, there are all sorts of different types of CCD's.

Up to now, what i've seen is that manufacturers such as Panasonic, do not sell the cutting edge CCD's they are using in their cameras(such as the DVX). They can afford to sell the DVX at a relatively small price because they build the CCD's themselves and in large quantities. They aren't dumb enough to sell the heart of their awesome cameras for other companies to exploit, and probably outsell the DVX or their VariCam for example.

However, nobody can stop us from breaking the camera open once we buy it.

Once again, if you find a concrete source for progressive scan video CCD's of matching or better specs to the DVX's, i'll be all over that. Trust me, i thought about it and researched it before starting on the DVX mod. :) I mean, i've found some progressive CCD's but they are horrible, nowehere near the output of the DVX.

Juan

[Peter Moore]

Are they unable to be adapted for video use instead of stills? If so that's a shame that you can't otherwise get good CCDs to use to mod your video cameras.

So what are all the different CCD types besides just the number of pixels? The only technology difference I've heard of is CCD vs. CMOS in still cameras.

[Juan P. Pertierra]

Peter,

Besides the frame sizes, there are different things to consider like pixel aspect ratios, sensitivity, chip sizes, and the rate at which the chip can read complete frames and how it does it.

For example, for astrophotography, you probably want a very sensitive CCD with the least amount of noise possible...most people also incorporate some method of cooling to reduce thermal noise. however, the CCD might not read enough complete frames per second to actually put out video...which is usually the case with cheaper CCD's. On still cameras you can have tiny size chips with large pixel counts...however the readout times are long because you only want one frame.

So in essence, CCD's with good sensitivity, low noise and fast readout times, as needed for video, are among the most expensive to come by. i think camera/chip manufacturers are plenty aware of how easy it is to hookup CCD's to A/D converters and record the output, so they are doing their best to keep the cutting edge stuff innaccessible to all but the large companies who can pay them the $$$.

Take for example, some video cameras that record DV, but also take hi-res pictures. The CCD's have the pixel count, but it probably can only read a fraction of those pixels fast enough to put together video....the complete frame is read out slower, which is only good for stills or extremly slow, SLR burst-like video.

Sorry if this sounds a bit like gibberish, it's been a long day...

Juan

[Peter Moore]

Fascinating stuff Juan, thanks. (and I did understand the technobabble :) )