Hitachi CML174... 24bit or 18bit color?

[kogo]

I ordered one of these from pcnation under the impression that the general consensus belived they could do 24 bit color. Apparantly Hitachi is still saying it displays 18 bit color, according to Jim Witowski. Does anyone know for a fact that the Planar px171 does 24bit? Seemingly it still does though using the same tft. Im probably going to cancel my order and go with the planar. Hitachis reply seems pretty definative, but Im hoping there is still some shred of hope... I didnt want integrated speakers

 

[gourdo_1]

If you read through some of the recent CML174 threads, you'll find that it was pretty much decided that the hitachi either has a 24-bit display or that its interpolated 18-bits is virtually indistinguishable from 24-bits for all intents and purposes. I have a CML174, performed extensive gradient testing with photoshop and am convinced that it's as good at reproducing color as any CRT. It's not a perfect monitor by any means, but if that's your only worry, I strongly recommend you buy one. If you can tell a difference, come back to this forum and tell me I'm full of it.

Incidentaly, I heard that the Planar was going to be based on the same panel (by AU Optronics), so you might be out of luck there anyway.

--Gordo

 

[Rob423]

Ordered my CML 174 Hitachi from MonitorsDirect.com and it should be arriving this Friday... i will let you know how everything performs!

Is THG Slightly Slacking??

 

[bobmitch]

Go back a few pages and read:

http://forumz.tomshardware.com/ce/modules.php?name=Forums&file=viewtopic&p=12332#12332

 

[kogo]

I read that thread at least 3 times. So you tell me, what's the answer? I certainly couldn't find it.

 

[flamethrower205]

The answer is that it's either 24 bit, or uses FRC circuit to make it seem that way, and that color reproduction is good.

"If everything seems under control, you're just not going fast enough."
- Mario Andretti

 

[Dangling]

I've had this monitor for 3 weeks now. I can honestly say it's 18bit. It's hard to tell the difference when it's displaying bright colors but when viewing dark pictures, DVDs or games, I noticed there's less details compare to my old monitor which can display 16mil colors. For your information, 24bit = 256 levels/color, 18bit = 64 levels/color

 

[kogo]

Damn, that does it for me Dangling. I guess this one is gonna be cancelled for sure... I'm just going to go with the Planar PX171.

Thanks for the help.

 

[flamethrower205]

You know, that may not be b/c the color, rather that lcd's in general have a hard time with darker colors and blocking light effectively. You say that it's not noticeable w/ brighter colors- it should be cause the lessers colors would be visible throughout, not just in a specific area of shades........

"If everything seems under control, you're just not going fast enough."
- Mario Andretti

 

[Guest]

As you'll see certainly soon on THG, we have tested the CML174SXW. The review is already on Tom FR (http://www.tomshardware.fr/articlemoniteur.php?IdArticle=219&NumPage=1), I believe they are translating it in American.

As usual, we've counted the colors displayed.
- 248 reds
- 255 greens
- 252 blues
248 x 255 x 252 = 15 936 480
We're quiet close to the 16 millions colors, isn't it ?

Vincent Alzieu
vincent@tomshardware.fr

 

[kogo]

Damn... 2\5 though for number of colors shown in DVI... D:
That's kind of discouraging, but other than that, looks like a kickass monitor. It's likely that it's closer to 24bit than it is to 18bit, and hitachi was just being cautious in their specifying, wheras planar was being generous. They both use the same screen, but I'm going to hold out for a planar review first.

 

[gourdo_1]

Both the Hitachi and Planar are technically 18-bit displays as indicated in the AU Optronics panel spec here:

http://www.acmepoint.com/taiwan/customer-service/pdf/T17A3_spec.pdf

If you go to page 14, you'll notice mention of the term FRC. FRC stands for "Frame Rate Control". FRC is a method of interpolating more colors than a display can actually proudce by quickly alternating between two colors. For example, gray could be created by alternating between black and white many times very quickly. Read here for more on FRC:

http://www.pixtech.com/product/grayscale.pdf

So, we know the panel used in these two monitors is the same, and it's the panel's integrated controller that determines how many colors it supports and how it renders them. Therefore the only real difference (color-wise) is in how each manufacturer chooses to market it. As a related example, you can see that Eizo chooses to use both numbers (actual and FRC-enhanced color depth) in the marketing materials of their monitors:

http://ebiz.netopia.com/flatscreentv/brochure2/list.nhtml
http://www.eizo.co.jp/welcome/products/lcd/comparison/comp05.html

So, after having spent a great deal of time trying to figure out this mystery, I can say with a great deal of confidence that the number of colors rendered is really a non issue, however FRC-related flicker might be. I suspect that the actual pixel refresh rate would have to be several multiples higher than the perceived liquid crystal refresh (60-75 Hz) in order to deliver that extra 2 bits per pixel.

On my CML174, I can see a bit of LCD flicker (not backlight flicker) when I view a single very bright green or red dot on a black background, though it might be likewise for any LCD panel. For pretty much any operating task, flicker seems non-existent.

--Gordo

 

[Rob423]

People BOUGHT THIS MONITOR in this COMMUNITY, every one i spoke to said it's an AMAZING MONITOR! who cares if the color says 32 bit, 24 bit, 18-bit or f*ckin 2 bits... if it views games good and looks bright and sharp, then that will do it for me.

Is THG Slightly Slacking??

 

[kogo]

The question isn't whether hitachi makes a good LCD, it's whether the planar could offer better color for a cheaper price. It's starting to seem like marketing differences at this point.. Im probably just going to call planar.

 

[bobmitch]

Just be aware! Different companies purchase panels on different tiers. Example...a tech friend explained that a lot of panel manufacturers purchase Samsung screens to put in their panels. The tier 1 companies purchase the "first run" panels with the fewest flaws. Then the remaining tiers are sold off at lesser prices...because of lesser quality. When I used to check certain brands, he told me to shy away because they were tier 3.

This is not to say that Planar is tier 2 or 3. Luckily...I learned from the techs at monitorsdirect.com that Planar and Hitachi have the "most well defined" dead pixel policies, where both say 1 dead pixel and up to 5 dead sub pixels. Other manufacturers either don't state it or say something like 9 dead pixels. Check around and see if Planar purchases their screens from the top or the middle. I can tell you that looking at the Hitachi screens, where I have yet to see a dead subpixel...they arre tier 1 purchasers.

Bob