SxS vs SDI (comparison)

[Martin Chab]

Here Untitled Document you can see a couple op pngs in full res that i took from the window of my studio. One is recorded on the SxS in 1080p HQ and the other captured with a Blackmagic in uncompressed 4:2:2 10 bit. I made the test very fast after receiving the camera back from the service for a firmware upgrade and i didnt realize that it was some picture profile on. I will make some more detailed tests and post it. So far I can see that if I zoom in on the pics, the one from the SxS shows some mosquito noise that is not present in the other from the SDI. I didnt have time to look much more but you can tell your opinions.

[Ted OMalley]

Um, I'll take your word for it. For my money, Long GOP Mpeg is pretty impressive, comparing it to SDI. I really don't see much difference!

Thanks for this!

[Noah Kadner]

It's hard to tell the way it looks in my browser as a still vs. playing back in motion on a calibrated monitor. Of course it's a no-brainer that the SDI should have less apparent compression artifacts compared to 35Mbit XDCAM HD. That said this is one of the best codecs I've seen yet in that infinite trade-off between efficiency, storage requirements and image quality.

-Noah

[Alister Chapman]

Mosquito noise in particular shows up more with a moving image as the noise varies from frame to frame.

The difference between the compressed and uncompressed material is small. I have done similar tests and visually the difference is very small. However there are artifacts introduced by the compression and no matter how small every de-code, re-encode process that your material may encounter from the edit to final viewing will add artifacts on top of artifacts. It is this concatenation that can lead to bigger problems further down the chain.

The MPEG produced by the EX cameras is very, very good and if handled carefully will produce stunning results. However if you can utilize the uncompressed output using something like a Flash XDR you will have material that should be more robust in post production.

[Piotr Wozniacki]

Originally Posted by Alister Chapman

Mosquito noise in particular shows up more with a moving image as the noise varies from frame to frame...

The "busy pixels" are only busy with moving images - comparing stills doesn't make sense to me.

[Martin Chab]

if you like when i make new tests i can post the footage instead of stills

[Piotr Wozniacki]

Originally Posted by Martin Chab

if you like when i make new tests i can post the footage instead of stills

Please do; would be of great interest - especially to those who're planning to buy FlashXDR.

[Bob Grant]

Which codec did you record to?

[edit] Pays to read the first post, 10 bit!

[Chris Hurd]

Originally Posted by Martin Chab

...I can see that if I zoom in on the pics, the one from the SxS shows some mosquito noise that is not present in the other from the SDI.

It's pretty a much a given that SDI is superior, but think about it: the average person viewing your material is *not* going to zoom in on the pics. I think Alister says it best by pointing out that "the MPEG produced by the EX cameras is very, very good and if handled carefully will produce stunning results." Enough said...

[Martin Chab]

May be there is no point to discuss if SDI is better or if the difference it would be seen, etc. Each tool is good or not for the intended work. I´m sure that for chroma keying or for extreme post treatment (call color grading or whatever) SDI will make a huge difference. To film my kid playing at the playground...well, of course i wouldnt take the extra work and cost that comes from shooting uncompressed. Anyway is good to know how much each system can give and that the whole point. I´ll continue the research and post the results.
Personally i work a lot making compositing and complex post-processing and sometimes i would give my entire kingdom for a better footage without noise, better color resolution, deeper chroma sampling and so on.

[Martin Chab]

Bob, the codec was Blackmagic 4:2:2 10 bits RGB uncompressed

[Chris Hurd]

Originally Posted by Martin Chab

I'll continue the research and post the results.

Yes, that is the main thing -- and please do so by all means. Many thanks for all you've done so far.

[Tom Roper]

The SDI improvement can be seen on the surface of the water. On the other pic it's not mosquito noise, it's mpeg block noise.

[Bill Spence]

Also, notice the dynamic range. I don't know if SDI bypasses the gama curves, but if you look at the side of the car in the SDI photo, it is much brighter and a lot more detail available around the wheel than on the MPEG picture. You see the same thing around the rusty bolts at the base of the column - you can see into the shadows there better in the SDI picture.

[Michael Maier]

Originally Posted by Alister Chapman

The difference between the compressed and uncompressed material is small. I have done similar tests and visually the difference is very small. However there are artifacts introduced by the compression and no matter how small every de-code, re-encode process that your material may encounter from the edit to final viewing will add artifacts on top of artifacts. It is this concatenation that can lead to bigger problems further down the chain.

Unless you convert all your footage to uncompressed or a lossless codec like ProRes. Then you can color correct and do effects without degradation. As good as the EX1 MPEG may be, MPEG is for acquisition only, like HDV. If you have anything more than just straight cuts you have to convert it to uncompressed or ProRes if you want no degradation.