HDLINK and PLASMA

[Bob Zelin]

the plasma that “everyone” uses, including Blackmagic and AJA, is the Panasonic TH50
series. At NAB2005, everyone used the Panasonic TH50PHD7UK, which has now been replaced with the (difficult to get delivery of) TH50PHD8UK, which is about $3000.

Because of the delay issue in all plasma screens, it has become difficult for me to recommend any plasma display, and urge people to stick with LCD’s, like the Cinema display, Dell, HP, Sony, and (if you can afford it) the eCinema. There are large LCD’s on the market, but I have never tried any of them with a HD Link, so I can’t tell you what does and does not work.

I would LOVE to hear back reports from anyone that has tried any 32″ – 46″ LCD screens with the HD Link.

Bob Zelin

[Shane Chadder]

Thanks Bob

What kind of delay are we talking about? How many frames? Does the delay vary by the type of input you are using?

[Luke Maslen]

Hi Shane,

Many HDLink users are successfully using HDLink with Plasma displays but we primarily test with LCD displays for a number of reasons. One reason is that there is no plasma display with full resolution HDTV at 1920 x 1080 pixels. The displays might be marked as HD1080 compatible but in reality, they simply accept a HD1080 signal, scale it down to whatever resolution the plasma display supports and then it might be scaled to fill the (comparitively low resolution) plasma screen.

Some plasma screens are really big and if that’s what you want, rather than pixel-for-pixel mapping, then a plasma screen can be very good when used with HDLink.

The color of many plasma displays has been enhanced to appeal to consumers and so if often inappropriate for use with any kind of color correction. The same can also be said of many LCD TV’s. However LCD monitors (not consumer TV’s) can be excellent for color correction.

You might find that your plasma screen is capable of scaling standard definition to fill the entire display even without the x2 scaling feature of HDLink.

If your plasma screen accepts a HD1080 (1920 x 1080) signal, then it should be able to accept NTSC at x2 from HDLink, ie 1440 x 972. However it might not accept PAL at x2 as that would require 1440 x 1152. The 1152 height might be more than the plasma display will accept. In this case, the PAL image would display at x1 even though you had specified x2.

A typical display which would accept this signal would be 1920 x 1200 pixels. The Apple and HP 23″ LCD and the Dell 24″ LCD displays all have a native resolution of 1920 x 1200 and will support both NTSC and PAL at x2 scaling.

Regards,

Luke Maslen
Blackmagic Design

[Bob Zelin]

Hi Shane – the delay is about 4 frames (3-5 frames) and can be “solved” with a Rane AVA-22d, which is about $600 US. Your plasma will now have “sync audio” but will be out of sync with the MAC computer monitors. Stick with LCD, unless you put the Plasma in a conference room.

Bob Zelin