Hd-sdi uncompressed...

moviemaker999

moviemaker999

Well-known member
is there anywhere I can see a still tiff or something from the hpx 500's hd-sdi port. 1920x1080 10 bit vs. 1280x1080 compressed.
Also, what is the dynamic range of the hpx500 recording to p2? And what would be the dynamic range difference going through hd-sdi 10bit ? How does the hpx500 Dynamic range compare to the hvx, as I do not know what the hvx200's is?

Thanks
 
I am waiting to see this as well, my guess is that 10-bit out of the sdi should get you about 9.5ish stops. The new convergent designs flashXDR records full-raster 1080p at 160mbps in mpeg2 @ 4:2:2 but its only 8-bit. I want to see hd-sdi to 10-bit cineform!
 
Its just a guess, but usually you get about the same dynamic range as your recorded bit depth. So the RED is 12-bit and it has about 11.3stops, the si-2k records 10-bit and it gets 10stops. 8-bit recording only gets your about 8 stops it seems (I have heard 8.33 was recorded with the hpx500) Anyways, please someone with an hd-sdi card on your computer, capture an uncompressed grab for us!
 
Give us about 2 weeks on this. We're base-lining the bare camera right now, and we've got a 72db (12 stops) OSG from DSC labs for this purpose. One thing we have not researched yet is the Decklink HD Pro, but if all works out, I believe we'll be able to do this.
 
moviemaker999 said:
Ok, but theres more to it right . I know my dvx isn't 8 stops DR.
Click to expand...

Increasing bit depth DOES NOT increase your dynamic range. It's just a good manufacturing rule of thumb, as well as encoding rule of thumb, match your bits and stops. You can cram quite a bit dynamic range into 8 bits if you want to. Just look at some DVDs with film originated footage. Thats a great example.

There is a risk that comes with pushing too much range into a smaller bit depth, and thats banding. It doesn't always show up though, and theres lots of tricks out there to prevent you from seeing it.

My DVX Andromeda captures a full 9.5 stops, but this is mostly due to the fact that I have total control over the cameras signal processing. Even in 8 bit mode, I can still pull 9.5 stops, but I end up seeing more banding in the image, especially on darker gradients. In 10 bit mode, the banding problems I get in 8 bit just aren't there. You really have to push your shadow contrast hard before you start seeing any banding problems, and I suspect most of it is just sensor noise.

Odds are pretty good you won't see any more dynamic range going out the SDI output, unless Panasonic has rigged it to be that way, which they may have. I wouldn't be surprised one bit. Smoother gradients are plenty good reason use it though.
 
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