I'm hoping they release an SDI verison first.......

Ditto!

So I'm now convinced that EX1 in fact does output higher quality video over HD-SDI. Thanks for insisting, and for illustrating your point (although I have not seen such pronounced stepping in my own greenscreen images, thankfully. I suspect this is because your model wears green shirt that might have some blue color in its fabric, which results in the keyer eating into it at lower sampling. Just a thought.)

Yeah... I must say that these examples from Jim not only show the even more pronounced difference between SxS compression and HDxSDI. They are also an eye-opener on the quality of SxS chroma keying being much lower than I expected!

Like Alex, I've never seen such a pronounced stepping in my (limited number of) keying.


Since nanoFlash does not seem to offer uncompressed capture like you did in your illustration, how much of a quality difference can we expect in SxS vs nanoFlash?



Alex, I don't think the (nano)Flash (XDR)'s 50 or 100Mbps compression will "spoil", or negate, the 4:2:2 advantages over 4:2:0 - the difference vs fully uncompressed should only influence motion-related phenomena. OK, perhaps some more tendency for macroblocking than in the uncompressed - but edge definition, I expect to be equally good.

Here is the chart that shows the quality of compression vs non compression listed on
the CD site...

http://www.convergent-design.com/downloads/nanoFlash/CODEC%20Quality%20Chart.jpg

You should see little if any difference between the non compressed footage from the HDSDI port ingested with the Sony Codec at 100 mbit ( Nano/XDR ) and the actual non compressed footage.

Looking at the chart, it only goes out to 50 mbps for the Sony PDW-700... you can put the
EX1/EX3 a little further out on the graph at 35 mbps and you will be able to see how the Nano/XDR will handle the non compressed footage at 100 mbps... it is approaching the HDCAM SR performance which is 440 Mbps at 1920 4:2:2 10 bit.... :-)

I'd have to say Sony has fine tuned this CODEC quite well....

While we are talking about the output quality of the camera I'd like to ask another question that some of you can answer please....

I know that no matter how good any footage is going into the encoder for DVD/Blu ray
authoring, you can actually damage the quality of the footage with the compression going to the disk during the write process....

I know that the compression is dependent on how much footage you plan on putting on the disk.. but I'd sure like to know at what rate can you put the footage on the disk before
you begin to introduce compression artifacts.... and what to use, CBR or VBR ....

It would be a shame to pull the footage from the HDSDI port and then just mess it all up
during the authoring process....

I can't address specifics of DCT compression(what's used on mpeg for DVD), but, I can say that the artifacting introduced in DCT is proportional to the frequency. What this means, in practical terms, is that the compression algorithm is stressed when there are very fine details in the image, such as foliage, waves on water, etc.

So, if the in-camera compression introduces small detail artifacts, the artifacts are greatly amplified in the compression process out to DVD/Bluray. Not only are the artifacts made more noticeable, but, the amount of disk space needed for a highly detailed image frame is higher than for an image frame with less detail. If you're up against a disk storage limit, you will then have to increase the compression ratio to get it to fit on the disk. End result is you get hit twice on quality because of the noise introduced on the in-camera capture process.

Alex, I don't think the (nano)Flash (XDR)'s 50 or 100Mbps compression will "spoil", or negate, the 4:2:2 advantages over 4:2:0 - the difference vs fully uncompressed should only influence motion-related phenomena. OK, perhaps some more tendency for macroblocking than in the uncompressed - but edge definition, I expect to be equally good.

What I don't understand is how nanoFlash (or other) will be able to feed a compact flash card (or even 4 of them at the same time) with a 100mbps data rate... If it would have been so simple, why would Sony use SxS ?
I think there is some kind of mistery here...

Who knows what Sony's reasons really are?

My opinion? Fast enough CF technology wasn't ready when the EX was being planned for. Sony wanted a card format that would work with mobile devices drectly at max speed. There is a progression from PCMCIA/Cardbus to ExpressCard as well.

The interface is more than just a "memory card", making additional options possible (PHU-60K, maybe even eSATA later on). And I also believe Sony wanted a "Professional" solution for which they could control the media quality (although by using the USB interface for the PHU-60K that seems to be out the window).

Anyway just my 2c.

George/

SxS has other advantages. SxS is very fast so it has plenty of head room for future development. It is very difficult to corrupt the file structure on an SxS card. Pull one out of the camera mid-shot or remove the power from the camera mid shot and the most you will loose is the last 4 seconds of the shot.