Thomson Viper with Flash XDR

[Mark Job]

Originally Posted by Perrone Ford

Just because you record in 8 bit doesn't mean you have to post in it...

...True. For some reason I just assumed Flash XDR was 10 bit. This is the reason I said shooting with an 8 bit camera doesn't matter, so much as recording your 8 space to 10 space and workflow stays 10 bit. However, it is what it is and importing an 8 bit file is but one hit against you. Dan was mentioning an eventual 10 bit uncompressed mode to come, so this would certainly improve things once more by allowing you to walk away with a 10 bit recorded file from an 8 bit camera :-)

[Perrone Ford]

Exactly. But I'd REALLY prefer to see 10 bit support in things OTHER than uncompressed. 10 bit uncompressed is REALLY going to burn through media. Would be great to get an hour's worth of 10 bit 4:2:2 for the ~$5k cost of the box.

[Mark Job]

Originally Posted by Perrone Ford

Exactly. But I'd REALLY prefer to see 10 bit support in things OTHER than uncompressed. 10 bit uncompressed is REALLY going to burn through media. Would be great to get an hour's worth of 10 bit 4:2:2 for the ~$5k cost of the box.

...Hey Perrone. Yeah, imagine 50 Mb & 100 Mb long Gop in 10 bit color space @ 4:2:2 ? Wow - especially with that super clean MPEG 2 encoding chip Convergent's got in there. Can you explain what the quality difference is between I frame and Long GOP MPEG 2 ?

[Dan Keaton]

Just to be clear, all MPEG2 is 8-bit.

When we implement full uncompressed, we can do 8 bit or 10 bit. This is no longer using MPEG2 as it is uncompressed.

If we do 10 bit, then you have your choice of using an 8 bit or 10 bit camera.

An 8 bit camera, with 10-bit full uncompressed, is still 8 bit's effective.

With an 8-bit camera, in 10-bit full uncompressed, the least most two binary digits will always be 0.

[Mark Job]

Originally Posted by Dan Keaton

Just to be clear, all MPEG2 is 8-bit.

When we implement full uncompressed, we can do 8 bit or 10 bit. This is no longer using MPEG2 as it is uncompressed.

If we do 10 bit, then you have your choice of using an 8 bit or 10 bit camera.

An 8 bit camera, with 10-bit full uncompressed, is still 8 bit's effective.

With an 8-bit camera, in 10-bit full uncompressed, the least most two binary digits will always be 0.

......Hey Dan MPEG 2 is 8 bit ! You learn something new every day :-)

[Michael Galvan]

Originally Posted by Dan Keaton

Just to be clear, all MPEG2 is 8-bit.

When we implement full uncompressed, we can do 8 bit or 10 bit. This is no longer using MPEG2 as it is uncompressed.

If we do 10 bit, then you have your choice of using an 8 bit or 10 bit camera.

An 8 bit camera, with 10-bit full uncompressed, is still 8 bit's effective.

With an 8-bit camera, in 10-bit full uncompressed, the least most two binary digits will always be 0.

Dan,

Do you happen to know whether the new Canon XL H1S is 8bit or 10bit out of its HD-SDI?

[Dan Keaton]

Dear Michael,

Sorry, but no.

[John Richard]

With the XLH1 it's been said that the HD-SDI stream is 10 bit, but that 2 of those 10 bits are 0's.

I have always been confused by this.

[Dan Keaton]

Dear John,

With the original XL H1, the HD-SDI signal only contains 8 bits of actual data from the camera, since the XL H1 is an 8-bit camera.

The HD-SDI standard calls for 10 bits.

So the 8 bits of data are put into a 10 bit word, with the 8 bits being the most significant part, then the least significant part, the last two bits, are set to zero.

It all works.

If a camera has 12 bits of resolution, then only the most significant 10 bits can be sent over HD-SDI. The last two bits of resolution would be dropped.

If a camera has less than 10 bits of resolution, then the bits are put into the most significant part, and the remainder is set to zeros.

The important thing is to examine the image visually.

With high bit-rates, the image can still be good (or great, depending on your opinion), with only 8 bits.

Examine the images from the Viper, using only 8-bits. The images look good and it is hard to find "banding". In my personal opinion, "banding" can be caused by a limited number of bits, or a low-bit rate, high compression codec.

I have never been troubled by "Banding" with my original XL H1. I have shot in situations where I expected banding, but could not find it.

In working with the XL H1s, at the Canon Booth last year, I tried hard to get banding, but I could find any. I was shooting at a finely graduated poster which I was positive I would see banding, but I did not. I was using the HD-SDI output going into a monitor.

I do feel that it is best to work in 10 bit in post.

[Mark Job]

Originally Posted by Dan Keaton

Dear John,

With the original XL H1, the HD-SDI signal only contains 8 bits of actual data from the camera, since the XL H1 is an 8-bit camera.

The HD-SDI standard calls for 10 bits.

....This was one of the reasons why I thought the XDR & the Nanoflash were 10 bit, because they both possessed an HD-SDI interface. Furthermore, I thought the XL H1 was 10 bit when recording from the HD-SDI output.