Decklink HD Product Choices

[Luke Maslen]

Hi Ralph,

You’re not the first person to ask a question in this forum about CRT monitors which include an HDMI input. Can you tell me why you would want to use an HDMI input with a CRT as I just don’t understand the benefit. My perspective is as follows.

All CRT monitors are analog monitors, even the ones that are categorized as SDI monitors. The reason I say this is that a digital to analog conversion is performed in the CRT monitor and the result is analog video. It is usually a very good conversion but the result is still analog so you cannot see individual pixels of video.

This contrasts to an all-digital workflow involving the HDLink and an LCD monitor. Video can be displayed with pixel-for-pixel accuracy in full 1920 x 1080 resolution. There is no introduction of analog noise and you can see every pixel on the display.

A HDMI input on a CRT display ultimately leads to analog monitoring and I don’t see how that is going to help you compared with monitoring via component analog input in a display which would presuambly be at lower cost.

The component analog output of the DeckLink HD Pro cards (4:2:2 and 4:4:4) is the result of a digital-to-analog conversion in the DeckLink card. It is extremely high quality and will look at least as good as a digital-to-analog conversion performed in a CRT monitor. Furthermore, many CRT monitors will automatically switch between standards when receiving component analog video but will need to be manually changed if digital video input is received and the format is changed.

So not only can you usually create a monitoring solution at lower cost using the DeckLink card to convert your digital video to analog, but it may be far more convenient.

If you want to output HD1080 and SD at the same time, then the DeckLink HD Pro 4:4:4 card is the model you will need as it performs split hardware down conversion of HD1080 material. When working in this mode:

[Ralph Keune]

Hi Luke,
Thanks for taking the time for the “complete” reply. I certainly understand your questioning regarding CRT’s and HDMI inputs. Your explanation and reasoning is both correct and thorough. I agree completely with your comments.

You wrote: “I would be very interested to learn why a CRT HDMI monitor might appeal to you.” Ultimately, what I’m trying to figure out is what combinations of outputs are available at the same time with which cards. (SD/HD/component/SDI)

In the post-production environment that I work in, I can see the need to (1) monitor the 1080i signal on a monitor that displays the interlaced signal in an interlaced mode. Field flickering can often go undetected (both in HD and SD formats) if viewed only on a progressive scan display. Also (2), I can see the need to make a downconverted dub for a client to review (whether composite for a VHS or analog component for a BetaSP/DVD recorder/etc.).

So, if I’m understanding correctly, with the Decklink Pro HD 4:4:4 card for example, I could output at the same time: SDI-HD and use a HDLink to convert and feed a CRT display, SDI-SD to feed a Digi-Beta deck, and downconverted analog component or composite. Correct? Any other “same-time” combinations?

Thanks again for your time.
-Ralph

[Tim Veal]

I don’t know Ralph’s reasons, but I’ve been looking into a similar situation for monitoring HD content on a CRT monitor. The reason is for color correction purposes. All the info I’ve found say that LCDs don’t give you the true range of black or accurate color reproduction for color correcting video. I realize that the CRT monitors I’ve looked at (Best Buy type of stores) aren’t Broadcast montitors, but they still are CRTs have dropped to be about the same price as the LCDs. So which is the best of the two evils?

[Luke Maslen]

Hi,

I would generally agree that broadcast or professional CRT’s are still best for color correction work and, especially for correct display of black. However I do not see how a HDMI input is of any benefit with CRT monitors. I can only guess that it might increase the price of the CRT monitor but for no particularly good reason. I suspect that people are just becoming so used to HDMI inputs that manufacturers may be adding them because people expect them.

There are many CRT’s available which are being marketed with video inputs but which do not advertise conformance with any SMPTE standards and I would lean towards using a high quality LCD monitor over a CRT of unknown quality.

We still use plenty of CRT’s in our testing and they are great but they do meet relevant SMPTE specifications. We also use LCD monitors with HDLink. Each technology has its pros and cons but watch out for cheap CRT’s which don’t mention whether they conform to common video SMPTE standards.

Regards,

Luke Maslen
Blackmagic Design

[Luke Maslen]

Hi Ralph,

I’m glad those comments made sense. I also agree that a CRT is best for finding field flicker issues in SD and HD. The component/composite output of the DeckLink HD Pro would be fine for this.

With the DeckLink HD Pro 4:4:4 card you can simultaneously output:

[Ralph Keune]

Luke,
Thanks again for taking time to explain the capabilities of the products in more detail!
-Ralph