AVS Forum banner
Status
Not open for further replies.
1 - 20 of 24 Posts

·
Registered
Joined
·
722 Posts
Discussion Starter · #1 ·
I have an uncallibrated G10($2600) and a nec9pg+ (crt)($1200). I have enjoyed the g10(at least for movies that arent too dark or too light) for the last 5 weeks, everyone who has seen it has been very impressed. The pg+ sat in the basement for about a week before i had time to set it up(I was dreading this). I didnt get it perfect but it only took about 5 minutes and the picture was vastly superior to the G10. I will not say that the fight is over yet because the g10 is uncallibrated with cr of 150/1. But I will say that it doesnt look good for the g10. If i can get these results in 5 minutes with no experiance Im sure the results can get alot better and the gap is already quite substantail. For the money I am delighted with the crt. AT THIS POINT I would strongly recommend to anyone plannig to buy an expensive fp to go with a crt. I will get the G10 callibrated hopefully by next week and post again with screen shots.
 

·
Registered
Joined
·
11,020 Posts
Quote:
Originally posted by madclammer
I will get the G10 callibrated hopefully by next week and post again with screen shots.
How are you going to get it calibrated?
 

·
Registered
Joined
·
66 Posts
Mad


I had a G11 calibrated by William Phelps. What a difference. This is a must have.


To get increased contrast from the projector the panels will need to be aligned and maximized. This is one of the many manual procedures William provides that Dilard does cannot do.

Dillard is very nice for everything else and its nice to have both.
 

·
Registered
Joined
·
4,720 Posts
madclammer,


To draw ANY conclusions with regard to purchasing CRT or D-ILA based on the comparison of a CRT to an uncalibrated

G10 is just not valid.


The uncalibrated G10 has been setup by JVC for use as its intended purpose of a business presentation projector. The

response curves have all been optimized for maximal light output - not for tracking a proper color temperature.


Although the CRT does need some fine tuning for optimal performance, it is still sold as a home theater product, and

its factor calibration is not as far off optimal as JVC's factory calibration of a G10, for use as a business projector.


One of the most important steps in the calibration of a G10, can't be done by DILARD - that is the adjustment of the

quarter-wave polarizers. This requires opening the case and making a manual adjustment.


A William Phelps calibration [ or those of his associates ] is what is really needed for a D-ILA to shine. Read the

review by Pat Megenity of Stereophile's Guide to Home Theater, who stated the D-ILA compared quite favorably with

his 9" CRT.


The D-ILA can approach a 9" CRT in quality [ although the CRT still has the edge in quality]. A machine that can do

that is not a "slam dunk" loser to all CRTs.
 

·
Registered
Joined
·
4,720 Posts
Quote:
Originally posted by madclammer
So assuming I do both I should get the Phelps first coorect? Can anyone tell me how much this will cost?
madclammer,


A William Phelps calibration includes the adjustments to the response curves that the DILARD calibration does.


The Phelps calibration was a few hundred dollars a while back - I don't know his current rate.


His username on the AVS Forum is "wm"
 

·
Registered
Joined
·
4,735 Posts
Quote:
Originally posted by madclammer
how much $, how much time? how much difference from dillard alone?
The good news for me was that Dillard made a huge difference on my M20 D-ILA. The bad news is that I put about 100 hours on the bulb making adjustments.


The CR is only 500:1, but the shadow detail is the best I've seen on digital projectors and the images are very 3D for being in a white walled room. And very smooth for a 116" wide image from
 

·
Registered
Joined
·
475 Posts
Dilard costs about $700 for the whole system, and you can calibrate the same projector over and over yourself.


I think I heard that wm charges about $900 (perhaps plus shipping your projector back and forth) for the same kind of calibrations that dilard does plus the quarter wave plate.


I went with Dilard, even though wm lives just a half hour away from me. It does take many hours of tweaking to get it right, but I enjoy that kind of thing and I think I got a picture as good as wm would have made it. The quarter wave plate should be optimally adjusted at the factory, and I haven't heard any reason to believe that it gets out of adjustment. I think it's one of those things where if the quarter wave plate happens to be misadjusted then wm would be helpful. But most folks probably have fine quarter wave plates, so dilard is the way to go for tweakers.


wm is definitely the way to go if you don't want to hassle.


-Tom
 

·
Registered
Joined
·
4,720 Posts
Quote:
Originally posted by PerfKnee
The quarter wave plate should be optimally adjusted at the factory, and I haven't heard any reason to believe that it gets out of adjustment. I think it's one of those things where if the quarter wave plate happens to be misadjusted then wm would be helpful. But most folks probably have fine quarter wave plates, so di
Tom,


I recall "wm" commenting about the quarter-wave polarizers a while back. As I recall, he hasn't found a single D-ILA

with the quater-wave polarizer adjusted properly for for HT application by the JVC factory.
 

·
Registered
Joined
·
475 Posts
Hmm... I am curious about that. I don't really know the details of the quarter wave plate, but from doing a little web search I understand that it is part of the optical system and that adjusting it adjusts the polarization of the light within the optical system. Presumably, it would be necessary to adjust it to whatever angle yielded the blackest blacks. In other words I'm assuming that the goal would be to adjust the quarter wave plates to the angle that yielded light whose polarization angle was exactly the angle that is filtered by polarization filters later on in the system for blacks.


Just thinking simplisticly, I would assume that that one setting would be the same as the setting that would yield maximum light output for whites (which is what business users want), because it would mean that the whites would be at exactly the angle that would be passed completely by the polarization filter.


At any rate, wm, if you are around please comment... when you adjust the quarter wave plate is it because JVC just didn't do a very good job of adjusting them at all, or is it because the settings for the business case are different from what is optimal for home theater? If the latter, please comment on what the difference between the two settings is.


-Tom
 

·
Registered
Joined
·
2,293 Posts
Quote:
Originally posted by PerfKnee


I think I heard that wm charges about $900 (perhaps plus shipping your projector back and forth) for the same kind of calibrations that dilard does plus the quarter wave plate.
Well, while the "same kind of calibrations that dilard does" is rather general, I must say that the two processes are quite different. I use my own software tools, and produce a significantly different result, even without the quarter wave plate adjustment. This is backed up by the graphs and data I collect and the customer reports on projectors that were Dilard calibrated and then Optimized by William Phelps. Dilard is good to be sure, and great for the do-it-yourself person, but it's not a subsitute for the calibration that I and my licensees do. Over 125 customers now and every one satisfied!


As near as I can tell from my experience, JVC does a good job of adjusting the quarter wave plates at the factory, at least lately. However, they do not do anything to "lock them in place", which still surprises me, and the projectors are subject to significant vibration during shipping. Even a tiny bit of rotation on the polarizer and the output of the panel at 0 IRE goes up significantly. I have found a few D-ILA projectors now that I could not improve in this regard, but only a few, and even with these I always check the adjustment and then seal them so they will not shift in shipping.


I have not found that adjusting the Q/W plates reduces the overall light output of the projector. Other adjustments do however, significantly. I believe that JVC adjusts the G15 series projectors to meet a light output specification, which results in a white that is usually not what we want for theater use. The limiting color is blue, the projector "runs out" of this first. So they let it go toward yellow to get that 1500 lumens of output. Adjusting the projector to track D65 usually means lowering the red and green output significantly, which lowers the total light output.
 

·
Registered
Joined
·
4,735 Posts
Quote:
Originally posted by PerfKnee
The quarter wave plate should be optimally adjusted at the factory, and I haven't heard any reason to believe that it gets out of adjustment.
I adjusted mine myself and they definitely needed it to get to a good CR.


I haven't had William do any adjustments for me (he helped me with one problem I had, though) but my guess is that other than time, the biggest advantage of having William do a calibration on a D-ILA would be at the very low light levels, where a set of professional eyeballs and his expensive equipment, etc, would seem like they could help. I feel like I got mine looking great with Dilard, but I can't rule out that William could do better.


With Dilard you of course get the chance to change things later (like as the bulb ages). I also have ColorFacts and the combination is nice, but it is a little more money.


--Darin
 

·
Registered
Joined
·
475 Posts
Thanks for the reply wm; you are clearly very knowledgeable about this.


I'm curious whether you offer quarter wave plate adjustments "ala carte" for Dilard users who like to do the electronic adjustments themselves, and if so what that costs. I would assume it would require a recalibration of the panel voltages from scratch after it was done, and that is okay.


Darin- How did you gain the knowledge to adjust the quarter wave yourself? If you can share with us the procedure you used, that would be very enlightening. I am curious about the basics, like how the adjustment is mechanically accomplished... is there some large or small screw that you adjust, or do you rotate the filters themselves with your fingers? I assume you use some kind of light meter to determine when you have reached a local minima.


-Tom
 

·
Registered
Joined
·
2,293 Posts
Tom,


Well, I could do just the Q/W adjustment, but the fee would probably not be to your liking... By the time I do all the setup work I might as well do the entire calibration run, and besides, I'm too much of a perfectionist to not complete the job.


I also do shading adjustments...
 

·
Registered
Joined
·
340 Posts
Quote:
Originally posted by Morbius
Tom,


I recall "wm" commenting about the quarter-wave polarizers a while back. As I recall, he hasn't found a single D-ILA

with the quater-wave polarizer adjusted properly for for HT application by the JVC factory.
This isn't true. William calibrated my G11 at my house, and I remember him checking the QWP and saying that it didn't need any adjustment.


- Chris
 

·
Premium Member
Joined
·
4,176 Posts
Speaking of quarter wave plates,


I just replaced the optical block in one of my G1000 DILA's (I have three DILA's, one primary unit that I use for home theater, plus two broken ones that I am attemping to repair). Somebody sold me an optical block for really cheap and I spent about 5 hours replacing the optical block.


The picture is now bright again on one of the G1000's but now there's too much red in the blacks and the whites are slightly red-deficient. (Blacks are very red, whites are slightly cyanish). This means that I think the red Quarter Wave Plate is out of whack, and the Quarter Wave Plate adjustment knobs aren't glued down like they are in the other G1000's.


Can anybody give me instructions on how to do a rough adjustment of the Quarter Wave Plate? I was given instructions at one point, basically having the top board pulled off and out of the way, and adjusting the QWP knobs. But I can't seem to find these instructions anymore.


(This is a formerly broken DILA I got off ebay for only $899 that I seem to have mostly successfully fixed, so I don't care to spend money sending this projector away for repairs.)


The friend that this $899 DILA is for, is not even willing to spend another $200 for a calibration, at least for the time being, so I am going to open up the top and adjust the QWP myself once I find the instructions that I lost.... I think it had something to do with adjusting the teethed metal knob (which is about 2 inch in diameter) while the top PWS board is off, to get the black field as dark as possible, and do it quickly because running the projector with the top circuit board labelled "PWS" removed from the optical block assembly, would eventually damage the LCOS panels. However, I am willing to do this because this DILA used to be a pile of junk before I fixed its optical block.)


The contrast ratio of my red is only approximately 10:1 or 15:1 .... But there's lots of red now coming through (unlike before) The green and blue looks okay at approximately a few hundred to one contrast.


William Phelps, can you enlighten me? I just need to do a somewhat crude adjustment of the red QWP. Please send me a PM if you can.

[Edit: Never mind, I found out how to adjust the Quarter Wave Plate.]
 

·
Premium Member
Joined
·
4,176 Posts
Oh, by the way,


Using DILARD, I recalibrated my primary G1000 DILA and boosted contrast a whopping 600% from a lousy 98:1 all the way to 712:1 .... I used to have an NEC XG135 CRT projector, and I now prefer the DILA overall when all the tradeoffs are factored in. It's more conveniently sized and easier to setup especially for a very busy guy who moves once every now and then. If you move more often than once every 5 years like me, then it's compelling to forget about CRT because of the size and inconvenience during moving between houses and apartments.


On my primary DILA, the blacks are better by CRT but the blacks on my DILA is now darker than the local movie theater. (Formerly, it was a lousy muddy grey like an old LCD projector).
 
1 - 20 of 24 Posts
Status
Not open for further replies.
Top