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09-05-2008, 02:10 AM
Evangelos,Originally Posted by Evangelos Achillopoulos
Isn't it true that decoupling error is an issue w/ 1-D LUTs? And that a 3-D LUT will not have this error since it works on R, G and B independently?
(I'm still new to this field, so I don't mean to sound smarter than I actually am, LOL.)
09-05-2008, 03:32 AM
Gabrielle, Bobby...
Ido at Israel has just completed successfully a full cycle test, he used an FW900...
http://www.reduser.net/forum/showthread.php?t=18545
In the next days I will test projectors for the job since I strongly suggest that reflected light is much better than transmitted light, so when I will finish my research, that will take some time, I will have an answer until then JVC HD100 is the best and alternatively the FW900 still is the best. A projector can be used in a small room 4m x 3m easily, Blase at Contact Studios NY is using it very successfully in a room of 5m x 3m... Unfortunately neither Blackmagic supports 4:4:4 10bit HDMI, they do 1,2, so only 4:2:2 10bit in blackmagic, which is worst than 4:4:4 8bit... probably a new Nvidia or the 4000 ATI will do it...
Its true the 3D LUT is "trying to fix" the lack of gamut, but even then, the image is really ugly to show to a client and ask him to imagine how good it will be in the film projection...
09-05-2008, 04:22 AM
Hey guys.
- 10 bit YCbCr 4:2:2 = 20 bit
- 8 bit RGB = 24 bit
- 10 bit RGB = 30 bit
10 bit SDI usually have YCbCr encoding, and uses only 2x10 bit channels, 10 bit for luma and 10bit for chroma. So 3x8 RGB bit is more.
Sometimes when people say 12bit color, they just mean 10+12 bit = 22 bit
http://en.wikipedia.org/wiki/Serial_Digital_Interface
Cheers
09-05-2008, 05:37 AM
Exactly Janne... 8bit in 4:4:4 is better than 10bit in 4:2:2... we are looking for 10bit 4:4:4...
09-06-2008, 07:01 AM
Evangelos, thank you very much for the reply.
So if I understand correctly, wouldn't DVI or DSub actually provide a higher quality signal than HD-SDI or HDMI 2? As HD-SDI and HDMI 2 are 4:2:2 (YUV) 10 bit, while (I believe) DVI is 4:4:4 (RGB) 8bit and DSub is just DVI converted to analog.
Thanks again.
09-09-2008, 05:28 PM
I thought I would get the thread back on the topic of the HP monitor...
I purchased an LP2480zx last week, and am generally pleased with it. Great blacks, rich color, best viewing angle I've seen for the price, and LUT calibration.
I'm currrently grading about 25 spots shot with six RED cameras in Apple Color (they converted all .r3d files to ProResHQ). We're monitoring via a Kona LHe SDI 4:2:2 out into an HDLink box into the DreamColor. I also have a Sony PVM-14L5/1 for comparison via the analog outs of the card.
A few things about the monitor:
-I think the built-in calibration (i.e., colorspace selection) can only be used via DVI. Those options were greyed out when connecting a Blue-Ray player via HDMI, and an HD signal via component.
-The Rec-709 calibration is not perfect. I am unsure if their specific probe would help fix this in my setup (HDLink), as I think it might only be useful if you are connected directly to a graphics card. When connected to the graphics card directly, Rec-709 did not look anywhere close to how it looks via my HDLink. Also, the default Rec-709 puts brightness at around 49 footlamberts (actually higher than the SMPTE spec ot 24 or 29), however that was way too dark so I adjusted it by to eye to 150 FL. I also had to correct the white point slightly using the HDLink 1D LUT panel.
-Component input was crap. This was no surprise as I don't think the analog hardware is designed the way it is on a video monitor (i.e., my PVM or even my Panasonic consumer plasma). The signal was too saturated and colors were askew.
-There is little to no documentation as to how the calibration works, and again, what their probe would be useful for. I have tried to set the white point with an Eye-One Display2, but it ended up being way too warm. I wonder if that probe cannot accurately read LED screens.
I previously was using a similar setup. I had an Eizo CG241 with a Blackmagic HDLink Pro. I demo'd cineCube to try and generate a 3D LUT in REC-709 space. I was unsuccessful in finding a target profile that looked accurate (cineSpace provides two), and that is a whole other thread based on endless hours of testing... I placed that setup next to a JVC DT-V24L1DU, and they looked almost identical. But BOTH of those displays had terrible off-axis viewing. This HP blows viewing angle out of the water, and the Rec-709 LUT gets very close. I just need to find out how to calibrate it internally (there are no adjustments allowed besides xy mappings, black level, brightness). Perhaps that is what the HP probe is for, and maybe using it would calibrate the white point properly. The image also seems a tad saturated using this LUT.
In direct correspondence with BlackMagic, I was told none of their products (converters, cards, or otherwise) support the HDMI 1.3 spec to provide the 10-bit "deep color." This is from the horse's mouth. So far, I've yet to hear of a solution for getting SDI into this unit and maintaining 10-bits without compression or compromise.
Blair mentions he has dual-link DVI on his Multibridge, which sounds promising, though in my research the Multibridge doesn't have more than one DVI out.
We're always on the bleeding edge....
Andrew Huebscher
Los Angeles, CA
09-09-2008, 07:33 PM
Does anyone know if eCinema still sell the converter boxes to be use with your own LCD, and does it support 10bits?
Tek
09-10-2008, 12:40 AM
Hyperfocal,
It seems that almost no desktop monitor maker really implelments Rec 709 well. The gamma is more complicated than just plugging in 2.2. It has a linear portion at the darkest end. And even when when 2.2 is used for the expansion, the resulting value is then multiplied and divided by scaling factors, FWIU.
If I understand your post correctly, it seems that you were able to get the Eizo CG241's Rec 709 close to DreamColor's, but its off-angle viewing is nowhere near as good. Is that correct?
09-10-2008, 03:24 AM
In direct correspondence with BlackMagic, I was told none of their products (converters, cards, or otherwise) support the HDMI 1.3 spec to provide the 10-bit "deep color." This is from the horse's mouth. So far, I've yet to hear of a solution for getting SDI into this unit and maintaining 10-bits without compression or compromise.
Ohhh I didnt read the "none" word... sorry Andrew I know the same...
"I have talked with BMD guys on the phone and they told me from the USA office that they don't support 1,3... Andrew, can you be more specific?"
09-10-2008, 11:29 AM
Yes the linear portion of the shadows seem to be the hardest to map to an LCD, and that was my difficulty with cineSpace's HD targets (though their film targets, when taken through filmout tests, proved to be very accurate). When I dial in the DreamColor where I like it, I actually lose the 7.5 pluge bar, but it's the only way to put the black level where it needs to be compared to a CRT.
I did not do a side-by-side of the HP against the Eizo, so my accounts are based on how footage looked from memory (footage I shot and colored) on the Eizo against the current HP. Again, the Eizo had a 3D LUT generated by cineSpace inserted into the HDLink Pro (a process that took a bit of time to figure out).
The viewing angle of the DreamColor is excellent, as is the black level. It exceeds the Eizo in both of these areas. With the Eizo, even looking at it dead on, I would still see a change in contrast in the far corners of the screen. Eizo makes a great display, but IMO unsuitable for any environment where more than one viewer (I think that's part of the reasoning behind the hood).
Andrew Huebscher
Los Angeles, CA
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