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Discussion Starter · #1 ·
Just finished the LATEST shootout in the ongoing saga of picture quality between these two models. Here are the interesting results...


NEC sent to my office the 3rd VT540K, the previous two being unable to match the picture quality of my new VT540 which had a problem displaying in ceiling mount.


In a nutshell, the new VT540K was like the previous ones...

HOWEVER - on a whim, I went into the "picture" control menu (Which stands at the factory presets on my 540), and boosted the "contrast" to about 93-95%, and

VIOLA - the picture was VERY close to my 540! I have always used the white balance controls to adjust the contrast and the brightness. I'm pretty sure the "Contrast" and "brightness" controls in the picture menu are the same thing, just without the ability to adjust red, green, or blue separately.


ANYWAY, with some slight color tweaking, I could get the VT540K picture even slightly better than the 540 picture (bulb with 70 hours on it).


NOW MY QUESTION - is it possible that everything in the two different models are the same, just that the software controls of the contrast ratio are set to different standards? In other words "nominal" or center on the contrast fader on the 540 are the same as 85% on the 540K? On the 540K, 90-93% looks GREAT, 100% looks a little washed out with some blooming. On the 540, 60% looks great, with anything over 80% completely un-viewable.


So, If the only difference is the "normalized" marking on the contrast fader, is it dangerous to have that little "headroom" in the 540K? For those of you who have a lot of hours on your 540, have you had to continually raise the brightness/contrast levels as the bulb/projector ages? If not, then I'm keeping the 540K and sending back my 540! Good news for all the worried 540K owners out there. Long time 540 owners please respond with your experiences of changing settings over time - Thanks!
 

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I have about 860 hours on my VT540 (not K). I find that I have to bump contrast and brightness up a little for SD material. But the settings have not migrated as best as I can tell.


My White Balance contrast and brightness settings are ~85% and ~60%, respectively. Picture brightness is just below 50%, contrast is just above 50%. I must confess that I have tinkered since my initial AVIA encounter.


It sure would be nice if someone from NEC would officially comment on this situation considering the number of units being sold here. Great service overall, but I really don't like being kept in the dark (well, except for movie time http://www.avsforum.com/ubb/wink.gif )




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Is the picture control contrast more of a 'macro' setting and the white balance control more of a 'micro' control? After changing your picture contrast, how off 'center' are the white balance controls?


I was not able to compare the two 540's that I have access to yet ... I am crossing my fingers I find the same results as you next week!


Oh, by the way, did you try out the other 540K's with your new findings? Did they have the same positive results?


-Mike
 

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I find that with my VT540, I get the best results with the white balance controls centered, and the picture control contrast setting boosted to about 60%, and brightness down just a smidge to about 45%. I've tried boosting the white balance contrast settings, but have found I lose detail in the picture. Alternatively, I did try keeping the picture controls centered, and adjusting the white balance. Again, I got best results just boosting contrast a bit and reducing brightness a smaller bit. Seemed about the same as using the picture controls. Boosting both was way too much.

This is with a Dalite HiPower screen, high lamp setting. Could that explain the difference in our settings?

BTW, I find that the color balance looks less natural when using the economy bulb setting, no matter how I adjust things, so I've been happier with full output.
 

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I am using economy. How many hours have you enjoyed? (which is a euphamism to help ease the pain of bulb cost). I'm over 800.




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Discussion Starter · #7 ·
Interesting results! BB, your the first that I've seen to also notice the contrast difference. However, on the last K unit I had shipped (still in my possesion, by boosting the contrast way up, the picture seemed to match my 540 almost exactly - i.e. black levels seemed as dark or darker than the 540. It has a very vivid and saturated picture, with high dynamic contrast. However, as i have misplaced my Video essentials disk (duh), I haven't been able to run any official set-up tests. With your report, I gues I need to go and purchase the Avia disk and try the black level contrast test. I use a Toshiba 2809 DVD which has always done really well on pluge patterns, as well as other greyscale patterns, so if I can't get it to work, I'll know its not the source. I'll let everyone know. By the way, the good 540 unit I have was made in Japan, all of the K units I have have been from China, made in April.
 

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TSO, have you asked NEC if they will send you a Japanese made VT540K? That would be a more definitive answer in finding if it is a manufacturing plant issue.


What did NEC say about the contrast findings?


-Mike
 

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I am now on my 4th VT540 / VT540K -- I've been enduring round after round of exchanges in search of one that doesn't have noticable pixel defects. I'm appreciative of NEC's working with me on this, but I'm also getting kind of tired of it. As others have mentioned, the people at NEC are very nice & accommodating.


Here are my findings based on sample size of four:

1) VT540K Assembled in China -- weak contrast

2) VT540 Assembled in Japan -- good contrast

3) VT540 Assembled in Japan -- good contrast

4) VT540 Assembled in China -- weak contrast


There are definite differences between picture quality of these 2 "flavors." I did try to boost up contrast, as TSO suggested. My findings are that you can get the weaker units to go as bright as the better units by pushing up contrast -- HOWEVER, this comes at a penalty with respect to black level.


Last night I did a shoot out between the 2 projectors that I still have in my posession (3 & 4 above). I used econo-mode & the Natural 2 gamma setting. Source was an HTPC using PowerDVD.


I put the vertical brightness steps test screen (gray vertical bars graduated from white to black) from Avia up. The better unit was able to be easily tweaked to show steady progression from black to white. I was unable to tweak the weaker unit to do this: If my brightness was high enough to tell the darkest bars apart, the bright bars merged together (& vice versa).


On the standard blue bars test screen, there is a section with a white box with two moving very light gray bars in it (one slightly darker than the other). The better unit could be adjusted to see both moving bars & then tweaked to make one of them disappear (blend into the white box), with the other remaining faintly visible. The weaker unit couldn't do this at all.


A couple of other observations:

- Colors out of the box on all 4 units were just about perfect, as measured with the blue bars test screen & a blue filter,as well as measured on the color decoder test screen & all 3 colored filters.

- I couldn't get the black bars test screen (which is used for setting brightness to work on any of the units -- no amount of tweaking would make the two slightly less black bars inside the big black box to become distinct. I don't know if this is a limitation of the source or the projectors.


I'd appreciate hearing any comments / suggestions regarding the above.


Thanks and regards

BB80301



[This message has been edited by bb80301 (edited 05-24-2001).]
 

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Discussion Starter · #10 ·
Ok...I tried the two different models out on with the Avia test patterns last night, and here are my findings.


*The 540 classic, which has a good looking picture with only minimal tweaking, would not pass the contrast and brightness tests in the configuration I had it (which is much like the configurations of others. No surprise - I had to lower the contrast level to about 30% in order to pass the contrast test, and the brightness was set at 50%, or factory setting. THis was done with the 540 in High lamp mode, normal gamma setting, and white balance controls all at factory. IN this mode, it would pass all brightness and contrast tests. However...the resulting picture looked very washed out, a little dim, and not very inviting.


*leaving that projector in with those settings, I did the same test with the 540K. Starting at what I had thought were good looking settings - none of the contrast tests were passed. Putting everything back to default and starting from scratch (just like the 540 set-up) I began adjusting the contrast and brightness modes until the tests were all basically passed. No surprise - the contrast was at about 60% and the brightness just one click over nominal. And, like the 540, when looking at the picture (used the Gladiator and Lost in Space DVD's), the picture was washed out and dull, just like the 540 classic.


CONCLUSIONS - despite the different software settings, it appears that the light engine and LCD panels are pretty much the same in both models. The difference is in the reference settings and scale on the picture controls. If one could "re-initialize" the 540K's settings to change the normalized (factory) settings, then they would be about the same, other than very slight color differences and of course, pixel condition. BY THE WAY, in FOUR different models I have tested, there were NO stuck pixels, and only a very few "dim" pixels which could not be seen other than by close inspection of the screen.


*The 540k and the 540 had great color rendition. Beuatifully balanced with very little red push. One benefitted from a little blue boost, while one benefitted from a little green cut.


*None of the 540's were completely "calibratable" in all the greyscale tests. If the projector were calibrated to pass the contrast and brightness tests, the grey scale sweep tests were not perfect (i.e, the last two bars on the scale, darkest and next to darkest, were alike, or if adjusted to be distinguiishable, the two lightest bars would be alike). You could recalibrate to achieve a continuous grey scale across ALL of the bars, but then you wouldn't pass the brighness tests, etc.


I'll ask again for an impromptu poll - have any of you with hours on your 540 had to coninually bring up the contrast level as the bulb/electronics age? If not, then I think either the 540 or the 540K will be fine. Its just a little scary having only 5-7% headroom on the contrast scale with the 540K.
 

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TSO:


Thanks for taking the time to test out your projectors w/ Avia & write up what you found. The way that I approached brightness & contrast "calibration" was to simply put up the vertical gray bar test screen & tweak until it looked as good as possible -- i.e., a reasonable progression where the bars looked as distinct from one another as possible.


When I watched a movie (Jerry McGuire) using these settings, the picture looked really good (on the Japanese-made VT540) -- not washed out.


A question for you -- what are the manufacture locations for the VT540 and VT540K's that you're using?


I'm glad to hear that you've had good experiences re: pixels. I didn't think that it would be so hard to get one that doesn't have serious defects (3 of the 4 had VERY bright blue stuck pixels & 1 had a dim red stuck pixel and a bunch of green dust spots).


I've got a new VT540 (manufactured in Japan) waiting for me at home to test out tonight. I'll report on findings.


Thanks, again, and regards

BB80301
 

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Quote:
Originally posted by rickforrest:
BB and TSO -


I bet the differences you guys are experiencing are related to your screens. Or did you already state what screen you were using?

Rick:


HT is still under construction, so I'm using a white wall. Image size is approx. 6 ft. wide.


Regards

BB80301
 

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I got a chance to fire up the replacement projector that I received via FedEx this AM. I feel like I won the lotto...


VT540

Manufactured in Japan 8/00

No bad pixels or dust

Excellent colors & contrast


I'm very appreciative of NEC's working through this with me. I'm also glad that I had the patience to work through it to get a unit that I'm satisfied with.


I don't think that one can draw any definitive conclusions re: VT540 vs VT540K or manufactured in Japan vs. China based on my experiences. However, my advice would be to go for projectors manufactured in Japan.


Regards

BB80301
 
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