SDI vs HDMI

[danu prasd]

Guys,

Which one is best ? in terms of quality, technical issues and prices...From what I've read and search, more information coming from SDI than HDMI ( timecode, metadata etc )....

thanks for the information,
d.p

 

[Nicolò Rebughini]

I prefer SDI, much better connector and BNC cables are cheaper than HDMI in price/length.

 

[Christoffer Glans]

There should be a way to make HDMI carry the same amount of info as SDI, it's just digital and the 1.3 connector can carry a stereoscopic image with an update.

I don't know but I seem to recall that SDI can't carry a true progressive 1080p signal, but HDMI can. Don't know if that's true though as two SDI can carry the 3K Arri Alexa Raw signal.

 

[Tom.Wong]

hdmi 1.4a can carry a lot more than SDI even compared to dual link or 3 g sdi.

can give you resolution up to 4k, 3d (1080p/60p), and true rgb as well.

but downfalls are hdmi are

flakey connectors

least robustness in cable design, i've seen plenty of hdmi cables kick the bucket and stop working, never had an issue with sdi

no timecode, huge no no in post and production if you're using it for capture, fine if it's just for monitoring.

SDI has industry standard specs that need to be abided by, and thus will work the same way every time, and all the tech that goes behind it abides by that. HDMI is still a consumer connection in the end, and you will have varying results on a broad spectrum. a hdmi splitter not working with this connection, a type of monitor or panel not working period, etc.

you can run much longer lengths with SDI.

as far as I know, you can use things to genlock sdi, but you can't with hdmi. (someone correct me if i'm wrong)


so my belief is that HDMI is a GREAT monitoring solution, especially in a 4k present/feature, hdmi 1.4a is gonna be a nice simple way of viewing 4k without needing quad connections. same with on set monitoring and viewing, but for full on post and production work, SDI will be around.

Im hoping they'll have dual link 3g sdi, or single link 6g one day for true 4k capture and monitoring, minimizing the amount of connections you need.

 

[Alexander Ibrahim]

Guys,

Which one is best ? in terms of quality, technical issues and prices...From what I've read and search, more information coming from SDI than HDMI ( timecode, metadata etc )....

thanks for the information,
d.p

HDMI is surprisingly capable.

12+ bit per channel color and resolutions of 1080/60p 4:4:4 with HDMI 1.3

3D and 4K with HDMI 1.4

The big challenge is finding gear with HDMI that is up to the specifications of professional post. Plasma TV's are very good choices, but you have to calibrate carefully and in my opinion more often than real broadcast monitors.

I like to use SDI to HDMI converters that have support for LUTs in the signal chain and calibrate via the LUT. Consumer gear only has fairly gross adjustments for calibration.

Now, if you have an ISF kit, you can calibrate the displays much better- and almost treat them as a professional display.

Ultimately I want a proper HD-SDI grading display because they are by far the most stable working environments.

As was already said HD-SDI is superior- better cabling, and build quality throughout. The question is whether or not your business can support the expense.

My business? I do all my broadcast monitoring on a Samsung Plasma TV.

I'll upgrade to a 3D Plasma TV or some other display tech ... OLED or something if they get cheap. I'm far less interested in LCD because black levels are VERY important to how I see images.

Ultimately I expect to shift the display I look at for work to a Flanders Scientific grading panel.

For i/o I bought a BlackMagic Designs (BMD) Decklink Extreme 3D+. I picked it over the AJA solution because it supports Resolve. It has all the features of the AJA product, but it costs about half ... so I can buy a BMD Decklink Extreme 3D+ and Resolve for the price of just the Kona 3G 3D card.

The Black Magic and AJA cards are the ONLY cards I considered for my setup, and both support HDMI and 3G HD SDI (plus dual link HD SDI) and 3D. My testing detected very little technical difference in the quality of both cards. I do feel AJA support is better - but that doesn't make Black Magic Support bad.

In AJA's favor is a slightly higher build quality, and direct support for using the Kona as a 3rd Monitor in OS X and Windows- that way you can see proper broadcast aspect and color on just about any application. If Nuke or Shake were part of my everyday workflow, the Kona would gain a lot of favor.

In the Decklink's favor, is price and the support for Resolve. I do a lot more coloring work than I do compositing, and Resolve is by far the best coloring software anywhere close to my price range- and quite frankly its far better than most of the competition at ANY price.

I picked the BlackMagic card, and have been rather happy. The main downside I discovered is that contrary to their advertising on their website, the card does not support applications, like Shake, that need to use a display through the GUI. In other words they do not support the use of the HDMI as a broadcast display with ordinary OS X apps.

When I spoke to Black Magic support about this issue, one guy was a jerk, the other was very nice about esplaingint that they removed the feature in order to be compatible with Snow Leopard, and it was unlikely that they would add it back in, or directly support a lot of the now unsupported apps. I was asking about Shake for my own use, but I took a quick poll --- Nuke and most of the Autodesk apps wouldn't get support.

I think its super CRAP that they list support for an application, and then don't support it.

Right now, I've had to use the Plasma via a MiniDisplayport to HDMI adaptor for some applications, and I am using the BMD card for all my actual broadcast applications- like FCP and Color. It's a nuisance, not a deal breaker- but I would have felt better if BMD had been honest in their marketing and I could have planed for it instead of having to react on the fly later.

That's my quick take. Hope it helps.

 

[Dan Kanes]

The worst Part about HDMI is the connector type.

My belief is they should unveil HDMI 2.0 which has the same protocols as 1.4 - but uses a nice strong Lemo Connector. I'd pay for a more robust connector. A lot more. there is nothing wrong with the protocol - just the fragile ass connectors.

 

[Tom.Wong]

i think in a post environment, HDMI is gonna creep in as the absolute standard. agreed to the new connection type, and if they can get timecode in there too, it will dominate in the post realm. less connections for higher resolution, more color information, the whole 9 yards.

In the field however I don't feel like it's gonna cut it. again price in length, max length before single loss, and a kind of shot in the dark with protocol standards makes it bust and unreliable for production.

i'm still hoping for my 6g sdi and above one day. or maybe the cable has reached its limitations, i have no clue.

 

[danu prasd]

thanks a lot, guys...

I think HDMI is perfect solution for monitoring...but again, for production site ( shooting ), may I say SDI is the best choice ? since at my country, we still live in the world of analog ( mostly use Cinelog as video playback ). It's easier to find SDI to Composite downconverter. And also, most common consideration, cables.

Thanks for the input, guys...really much appreciate it....but pls feel free if you have any other opinions....

d.p