4:4:4 Uncompressed 1080i HDR-FX1?

[Wayne Morellini]

Discussion. How would you do a mod like the DVX100 uncompressed mod, on this camera?


Wayne.

[Phil Rhodes]

Hi,

Using a sodding great disk array, for starters.

But it'd be theoretically the same thing.

Phil

[Juan P. Pertierra]

The device would be the same, but it might have to be modified for the much larger throughput of HD, as well as the drives.

Juan

[Charles Moore]

Apparently the new Sony camera doesn't even use 1440x1080 chips like the HDV spec calls for. According to some its doing some sort of "upsampling" to achieve 1440. Maybe it's better to wait to see what JVC comes out with in December.

[Charles Moore]

By the way Juan...would it be possible/practical to create an HD- SDI output from one of these HDV cameras that would interface with one of the new and cheap HD-SDI capture cards such as Black Magic Decklink HD? Or is component analog a better/easier option?

[Juan M. M. Fiebelkorn]

In fact I guess the JVC camera has a higher true resolution than the Sony's.
Anyway that is questionable, what have more spatial resolution one 1280x720 Bayer chip or three 960x1080 (which in fact ends at 960x540 ,Remember the Sony's is interlaced) chips?
Both has 4:2:0 color sampling so there is no color resolution advantage.
I guess the only advantage would be the better highlights management the Sony's surely will have.........

[Wayne Morellini]

The Sony would have a number of advantages. it is not just 960*540*60, but 960*540*3*60, which is just as valid, as it interpolates, as bayer does. The light is spread accross three chips, without desentising, light wasting, filters, and the pixels are bigger than if they were true 1080's which gives them a spread much better than a bayer 720p 1/3inch chip, and much better sensitivity and accuracy. If we sat down and did the calculations, it would be interesting to see what size bayer chip we would need to match it. I also would not expect the full benefit to be taken advantage of, as it is a cheap prosumer camera (like the VX1000 was of lower grade compared to vx2000).

But yes, the interlace scheeme, and 4:2:0, does let it down when compared to a 60fps 720p cinema camera, but for the HDTV market most of the stuff is at most 60i. I think we can do much better with the cinema cameras, but there is something about a complete prebuilt system that can be made to record to disk (if it canbe raw moded) aswell as tape when needed, that is appealing to lots of people.

[Rob Lohman]

<<<-- it is not just 960*540*60, but 960*540*3*60, which is just as valid, as it interpolates, as bayer does. -->>>

Wayne: are you saying that it does not matter whether you have
a single chip bayer or a 3-chip system?

[Wayne Morellini]

No, not at all, I'm saying that 3 chip expands your pixel area (3 sensor cells per pixel) and the pixels are bigger than they would be if they were true 1920 * 1080. This (without the bayer filter) gives better sensitivity and range of charge it can accumulate. But in this case the interpolation and possible other 4:2:0 etc dumbing down of the HDV model, brings it down compared to what we are doing. Otherwise we would need effective sensor areas much bigger than theirs, more pixels etc to compete with it, then I still haven't calculated how we get past the filter limited sensitivity.

I think one thing the machine vision box cameras offers, is probably very good filters, and access to pure data. In a lot of prosumer cameras they don't have correct gamma curves, 8-bit colour, 4:1:1/4:2:0, and they oversatuate, which flattens colour and luminance detail even more. I don't know how they do it but I suspect they take all the colour channels and move/or squeeze them up, maybe stretching from the bottom to maintain pure blacks, to give that flat, play school, crayon style, mini-dv look. So even a bayer 720p cinema camera might be better than a top of the line 3 chip prosumer mini-dv, even passed through the mini-dv codec, and work out cheaper in future.

But this is not what this thread is about, but generating interest in raw from the Sony, which camera is probably going to displace the DVX100 for indie. Some people will go for the Sony, some for the cinema camera project, and some for a raw Sony, to each his own (but without true 1080/720p 3 chip 1/3+inch, 50-100Mbs codec, I don't want to buy one).

[Obin Olson]

Sony Makes it very hard to use the HD camera for filmmaking because its not progressive scan at all

[Aaron Shaw]

Isn't that just a software issue though? Or are the chips not capable of capturing in that manner? If it's just software then I don't see much of a problem as an image would be taken directly off of the CCDs.

[Phil Rhodes]

Hi,

The scan characteristics are specific to the CCD. Some can do both, some can do one or the other, but if you have an interlaced scan CCD, it's generally never going to do progressive. Some of the types which will theoretically do progressive would require massive changes to hardware beyond the ADCs if it wasn't already implemented in the camera.

Phil

[Aaron Shaw]

Thanks for the info Phil :)

[Wayne Morellini]

Something I forgot to mention before. I think the interlace scan is both a disadvantage and a benefit.

One it takes away from a clean progressive image, but it also reveals extra temporal/pixel detail about the image that canbe extracted during deinterlacing. Requires a lot of extra processing though, and preferably RAW 4:4:4 output to bypass the 4:2:0 interlace problems.

[Charles Moore]

Although I have no way of verifying the info, reportedly the camera will have component ouput. I would expect this to be uncompressed.

This from avsforum.com:

"following Sony's press event in NY.
The change is related to the inputs and outputs."


"REVISED (Based on new/corrected information from Sony):
Features component video out (but NOT in)"