|Originally posted by VideoGrabber
I should mention that the old Visions (which I have) are somewhat bandwidth limited beyond 840p (but still look very good at 960p), and are exceeded by Lumagen's newer units.
Thanks for the update.
That's about right. Somewhere right before 960P. But the earlier Vision from Lumagen was one of my personal best. The Lumagen rep left one with Makrk Haflich to demo. We tested it and found it to be a very nice unit. It did everything well, it handled the test patterns flawlessly.
It's also a very well designed unit. They chose to use a clean power supply and buffer the analog out from the DAC. Adding the buffer to the DAC was a very good thing to do, as all DAC's should have buffers (and/or line drivers) for long (10'>) cable runs. It's a jewel of a scaler, that works exceptionally well when used properly. Mark now owns the later SDI version. I've not played with that one, but I'm pretty sure that SDI input would make better for a cleaner 960P conversion. I just don't think it's a good idea to scale an analog signal to 960P. And it's not only the Lumagen that has the roll-off near 960P, everything else I've looked at also roll-off before 960P. The exception is the non analog (SDI, HTPC) units that does a much better.
But for DVD and regular video, the Lumagen does very well, as with so many other scalers. The problem for these units is when/if the intent is to exceed 960P, and this is where I was going earlier with the discussion on 1080P for HDTV. Most of the better video cards will scale DVD to 1080P with ease (for those who watch DVD @ 1808P), but 1920x1080P HDTV is a whole different beast to contain. For the high end 9" CRT owners that are using HTPC cards for scalers, they should make sure they have a good engine in that HTPC for this HDTV standard, because 1080P HDTV is right around the corner.
1080P HDTV movie samples can be downloaded off the internet. But in order to experience those samples in it's fullness, everything in the video chain has to be at a super perfomance level. And yes, specs do lie. For instance, how is it that every brand, make model of cable being sold have a cable capacitance in the window of 15pf to 17pf. The better rated cables (RG6) are listed at or near 17pf. The cheap and very thin junk has the same figures :rolleyes:
Plus the average spec for a projector list the bandwidth of that projector, and that bandwidth is determined by the maximum scan rate of the projector. It has nothing to do with the video chain. Actually the manufacturer should make sure that the projectors video chain (bandwidth) match the maximum scan rate of the projector. in other words, the projector will sync-to very high scan rates, but the video circuit won't properly resolve the video bandwidth at that scan rate :rolleyes:
I've found one thing out over the past two weeks playing around with HDTV. It gonna need a lot of headroom, to really look good. Enough is not enough.