HDSDI OUT is 420

[Piotr Wozniacki]

Originally Posted by Sverker Hahn

My major concerns are noise in poor lighting conditions and white-outs in good light. Will a HDSDI 422 10-bit address these concerns?

The noise due to " poor lighting conditions " accumulates with that due to compression (the mosquito noise), therefore I'd say yes - it will.

You're right - the macroblocking is not an issue with the EX codec under normal viewing conditions, but for more elaborate editing (compositing, chroma keying) - the less of it the better, too.

But of course, no recording device/codec will make for poor exposure settings !

[Mike Schell]

Originally Posted by Sverker Hahn

The differences are minimal. Is it really worth the dollars to buy the Flash XDR? Many other factors may decrease sharpness and increase noise, so will the SDI out really make a difference?

In normal conditions, the EX1 gives such an extraordinary good picture that I doubt if such a little difference will be noticeably.

My major concerns are noise in poor lighting conditions and white-outs in good light. Will a HDSDI 422 10-bit address these concerns?

Hi Sverker-
It all depends on the application. I know that the BBC will not accept footage from the EX1/EX3 for their high-end shows, due to the 4:2:0 and 35 Mbps. They want 50Mbps 4:2:2 as a minimum. On the other hand, I do understand that they will accept EX1 + nano/XDR footage.

Likewise, Discovery HD ranks cameras in bronze, silver and gold classes. I understand that the EX1/EX3 is currently rank in the silver class. I am hopeful that the EX1 can be raised to the gold class with the addition of the nanoFlash running at 50 or 100 Mbps.

Also, don't forget the significant difference in media costs. 16GB SxS cards are running around $700, while 32GB CF cards are $115. This difference can really add up if you don't have access (or time) to offload the cards to a laptop. If you shoot any long events, the payback can come fairly quick.

[Sverker Hahn]

Originally Posted by Piotr Wozniacki

The noise due to " poor lighting conditions " accumulates with that due to compression (the mosquito noise), therefore I'd say yes - it will.

Good to know. I really didn´t know which was the real culprit here, the compression or physics/hardware. So they add up - of course it is that way.

Originally Posted by Piotr Wozniacki

You're right - the macroblocking is not an issue with the EX codec under normal viewing conditions, but for more elaborate editing (compositing, chroma keying) - the less of it the better, too.

Sorry, I don´t know what macroblocking is - and not even chroma keying. Will I ever come in contact with them when I us Apple´s Color.app? (I want to learn EVERYTHING!)

Originally Posted by Piotr Wozniacki

But of course, no recording device/codec will make for poor exposure settings !

Correct - I could have said it myself :-)

[Sverker Hahn]

Originally Posted by Mike Schell

Likewise, Discovery HD ranks cameras in bronze, silver and gold classes. I understand that the EX1/EX3 is currently rank in the silver class. I am hopeful that the EX1 can be raised to the gold class with the addition of the nanoFlash running at 50 or 100 Mbps.

Yes, I want my camera to to be of GOLD ;-)

Originally Posted by Mike Schell

Also, don't forget the significant difference in media costs. 16GB SxS cards are running around $700, while 32GB CF cards are $115. This difference can really add up if you don't have access (or time) to offload the cards to a laptop. If you shoot any long events, the payback can come fairly quick.

Yes, this will be an important difference. It could mean not needing to bring the MacBook on the wilderness trail for a whole day or even longer. More batteries are also needed ...

Thanks for feedback, Piotr and Mike.

[Craig Mieritz]

I like Perrone Ford's comments. It's all a matter of perspective. The cost savings for storage media for the Flash XDR nearly pays for the device, as opposed to the SxS cards, especially if you are shooting a long event/documentary or cannot afford to pay to have someone whose only job is transferring files all day. Get the tools that'll do what you want for where you want to be in the marketplace.

[Jim Arthurs]

Originally Posted by Sverker Hahn

The differences are minimal. Is it really worth the dollars to buy the Flash XDR? Many other factors may decrease sharpness and increase noise, so will the SDI out really make a difference?

Hi Sverker, it depends on what you are shooting. If you're doing blue or green screen then those differences are extremely important. The additional color information and the reduction in compression can save a shot that isn't perfect, or make good material key even better.

There is of course a limit to what the camera can do, but there is no question that the on-board recording format is the first limitation to the performance of the EX1 or any of the better HDV cameras.

Regards,

Jim Arthurs

[Mark David Williams]

Originally Posted by Jim Arthurs

First, Sony has answered this 4:2:0 vrs 4:2:2 question, several times;

Third, every time I do an HD-SDI compare to the native codec (as in blue or green screen work), I can clearly SEE the increase in chroma resolution... here's a sample from a clip I had on hand... This is a small crop, enlarge approx. 600%...

http://ftp.datausa.com/imageshoppe/o...compressed.png

Look at the borders of the red and white, notices how ragged the 4:2:0 images is compared to the 4:2:2 uncompressed sample. Note also the difference test I added in, which shows the areas where there are significant differences in the image...

Regards,

Jim Arthurs

I can't see a difference here? If this is 600% then what difference would be seen normally? I'd like to see pictures where there is a difference?

[Alex Raskin]

Thanks for posting the comparison pics, Jim.

For me, they actually reinforced the point that the differences are minuscule and won't affect anything in practical terms, including green screen work.

600x magnification, and images look just the same to the eye, unless you digitally extract the difference, which seems to be not much either. And to capture this, you'll have to invest 75% more than the cam's cost?

As for using CF cards for media, there's a couple of threads here where people cleverly use EX1 with CF card adapters to record on cheap CF cards. Certain adapter/card combinations work with CF cards, seemingly, without a hitch now.

See work in progress:

http://www.dvinfo.net/conf/sony-xdca...ex1-ex3-6.html

http://www.dvinfo.net/conf/sony-xdca...ory-ex1-2.html

Back to this thread though... isn't 422 suppose to have 2x more chroma information than 420? If so, how does that difference show, in layman terms?

My greenscreen tests showed zero visible quality difference between the keys made with either footage, SxS vs HD-SDI.

[Thomas Smet]

Originally Posted by Sverker Hahn

The differences are minimal. Is it really worth the dollars to buy the Flash XDR? Many other factors may decrease sharpness and increase noise, so will the SDI out really make a difference?

In normal conditions, the EX1 gives such an extraordinary good picture that I doubt if such a little difference will be noticeably.

My major concerns are noise in poor lighting conditions and white-outs in good light. Will a HDSDI 422 10-bit address these concerns?

Also keep in mind that the way mpeg2 compression works the more complex a scene the harder the encoder has to work. 35 mbits is a pretty good bitrate that can compensate for a very wide range of complexity but every now and then even that encoder could get stumped ith super fast movement or lots of random detail like blowing leaves or waterfalls. The higher the bitrate the better you will be to make sure most of this stuff will turn out great. Even HDV's 25 mbits is good enough for a talking head locked down shot. In fact broadcast HD at a max of 18 mbits can still look good for a lot of stuff. 50 mbits and 100 mbits makes sure you will never have any surprises with your footage when the situation gets complex.

[Steven Thomas]

If you can't see a difference and feel it's so small, stick with the XDCAM codec. Like Jim pointed out, 4:2:2 is your best bet for clean edge green or blue screen work.

But, I certainly can see the difference, especially as Thomas pointed out in more complex scenes.

Working with XDCAM footage over the last year, although it's no doubt one of the best mpeg compression verses data rate, more detailed scenes with motion can show mpeg artifacts. SDI will allow to capture your footage at a higher data rate to minimize these issues and also allow better chroma subsampling (4:2:2).

It's all about if you want the best possible. Certainly XDCAM codec does a great job.

[Thomas Smet]

Here is Jim's image showing just the chroma channels.

The way color compression works is that the lower sampling of color was designed so people wouldn't really notice it with the naked eye. The fact that some people just cannot tell isn't a shock to me at all.

When you isolate the chroma channels the way a keyer does you really start to notice the difference. Here you can clearly see there is a difference between 4:2:0 and 4:2:2.


At first I thought maybe the camera was up converting or filtering the chroma channels before it sends it out SDI but I don't think so anymore. The image Jim posted helped confirm it to me.

Look at the thin horizontal line in the upper left of the images. In the 4:2:0 version the line is clearly much thicker. This is because 4:2:0 can never have objects a pixel thin since it really works in blocks that are 2x2 pixels in size. So a thin line will will be twice as thick in the chroma channels in a 4:2:0 image.

If the video was chroma smoother or up sampled you would still end up having blocks of color that are bigger then the pixels on the luma channel. A chroma up sampler doesn't remove extra pixels, it just blurs the chroma channels only or fills in the missing chunks.

On the 4:2:2 version of the image the chroma line is clearly much thinner or what we would expect how it should look compared to the luma channel. Therefore I don't think it was up sampled at all but a true 4:2:2 output from the camera. If it was up sampled that thin line would be much thicker.



With all that garbage said however people have made a very valid point that 4:2:2 or 4:2:0 doesn't have to be a deal breaker. In many case even for keying 4:2:0 will give some pretty darn impressive results. In my experience as a compositor after I up sample the chroma about the only thing I get is a bit of color bleed on edges due to the larger cover area of the chroma pixels.

[Steven Thomas]

Thomas, Jim's EX1 sample is an excellent example of 4:2:0 vs 4:2:2 from the EX1.

Thanks for digging this up.

[David Heath]

It's worth mentioning again that the advantages of 4:2:2 over 4:2:0 are far greater with an interlace system than a progressive one - I'm assuming the images we've seen posted are from a progressive original?

Remember that when digital component video first came about, video was interlace, period. Hence the reasoning behind halving chroma resolution horizontally, but not vertically.

[Bill Ravens]

Funny that no one brings up motion artifacts, except for the allusions made by Thomas Smet. As far as I'm concerned, the 35Mbps bitrate from the EX1 is more than satisfactory UNTIL the camera starts panning, vertically or horizontally. As Thomas points out, it's in full frame motion(like a pan) where 35 mbps gets overwhelmed by the amount of compression it needs to do. Image blurring, aka motion artifacts become painfully apparent, especially on fine detail. Compression rates on the order of 50-100 mbps effectively reduce the amount of compression by 1/3-2/3rds, and hopefully, the motion artifacts. This has nothing to do, really, with chroma sampling rate or chroma keying. At least, this is my biggest hope for the nanoFlash I've ordered.

Please don't tell me to reduce my pan rate. I know the arguement, it's valid, up to a point. Motion artifacts can occur in other instances where in frame motion is a big part of the image frame.

[Steven Thomas]

A VERY vaild point David!