CurtPalme.com Home Theater Forum

danOO00 · Joined: 22 May 2007 Posts: 70 Location: Putnam County, NY

Hi

This is my first post here, but I have been absorbing a lot of information over the past few months since I bought my PG Xtra from Curt. Thanks to all who contribute regularly. This is a great forum, and the info here is invaluable.

First off, I would like to say Curt is first rate to deal with- great customer service. The set arrived as he described, and was in great condition out of the box. I am sure it has all been said before, but I want to mention this in my first post. Even when I fooled with the deflection H-Width pot trying to increase my raster -probably frying a component on the deflection board- he quickly repaired it and sent me on my way with a cheap (UPS shipping cost) lesson learned.

This is my first CRT projector, and I am glad I went this route over other "simple" digital options that I have seen and read about. The image it throws is really very film like and has definitely wow'd just about everyone who has seen it so far.

Here is my current setup:
NEC 6PGXtra 3500 hour with good condition "6.5 - 7" tubes.
HTPC Athlon 1400 with Radeon 9500 at 1080i 72Hz (very smooth pans), TheaterTek with overlay for DVD's. I know, Old School, but it works very well for me, and I am too cheap/lazy to upgrade right now.
Motorola HD cable box at 1080i using Kim's RTC2200 for the HTPC VGA pass through. I haven't fooled with gamma pot yet. I am waiting to dial everything else in first.
Screen is an AT electric rollup I picked up from SeymourAV. I went this route because the CRT rear projector lives behind it for regular TV watching.

So far I have ceiling mounted the set with the help of some friends. I also have managed to get the mechanical/convergence setup pretty nice thanks to all the documents and advice on this site.

Now I am trying to get the colors and gray scale calibrated as well. I just bought a Spyder2, and with the ColorHCFR application I get a very watchable gray scale track to my "unexperienced" eye.

I have some questions, and if they have been answered before I apologize, but need some guidance from the experienced here.

Is there an Idiot's guide specific to the PG for gray scale calibration with a color analyzer assuming the G2 is good?
If not would someone be willing to walk me through the process in this thread?
I assume my G2 is OK since I got the set from Curt Wink

Also, according to the Spyder/HCFR output (and my eyes!) it seems to track gray pretty well right now.

To calibrate I just moved the Kelvin R G B W/B sliders until I got a pretty flat response across the gray scale using HCFR and AVIA DVD on the HTPC. It looks good to me, but I would like to make sure I am getting the most out of time spent tweaking. What is the proper sequence to go about this procedure? I followed the advice here: http://curtpalme.com/NECPG_MechSetup8.shtm to eyeball the raster level as a starting point before I began white balance tweaking.

Thanks!

Dan

**AnalogRocks** · Posted: Wed May 30, 2007 8:52 pm Post subject:

Book'em DanOO00, I mean Welcome DanOO00

There's a document written by Curt for the NEC XG line of projectors. I'm not sure how much would apply to your PG but it may be of some help. Let me see if I can find the link.

**AnalogRocks** · Posted: Wed May 30, 2007 8:58 pm Post subject:

The documents are posted here:
https://www.curtpalme.com/forum_archived/viewtopic.php@t=4722.html

Not sure if it'll help but give it a read.

danOO00 · Joined: 22 May 2007 Posts: 70 Location: Putnam County, NY

Thanks for the link. I have read trough these docs, but they don't go into gray scale as far as I can see. There is also another XG doc about G2 in the advanced procedures, but this is specific to the XG, and I dont think much applies to the PG.

I know someone on this forum must have done this calibration in the past with a PG and has some tips. Very Happy

Dan

Mark_A_W · Posted: Thu May 31, 2007 3:16 am Post subject:

Dan, you've done what you should with the greyscale - just use the Kelvin B and W controls.

There's nothing specific to the PG when you do it that way, except you must turn off the blue defocus switch on the Deflection board, then focus blue electronically.

Then turn the defocus switch back on. Blue must be defocused for proper greyscale tracking. The switch gets it close, but sometimes more defocus is needed.

The actual greyscale tweaking is the same for all projectors.

Moose · Joined: 09 Mar 2006 Posts: 788 Location: Minnesota

There's this sticky over at that other forum - AVS - http://www.avsforum.com/avs-vb/showthread.php?t=852536 - in the Display Calibration Forum. Looks like it should be helpful to you (and me).

danOO00 · Joined: 22 May 2007 Posts: 70 Location: Putnam County, NY

Thanks guys. I just wanted to make sure I was doing it right, and it seems so. I will post with the results once I have a chance to run through the procedure again. I must say that this PG Xtra throws one hell of an image when you take the time to set it up. I would love to see how a 9" LC set compares in person.... Or do I....?

**AnalogRocks** · Posted: Thu May 31, 2007 2:53 pm Post subject:

Where are you located? You should update your location in your profile. Maybe someone near by has a 9" you can see.

( geeze that sounded so wrong ) lol

danOO00 · Joined: 22 May 2007 Posts: 70 Location: Putnam County, NY

I just added my location... but, I dont need projector envy so soon in the game. Thanks.

danOO00 · Joined: 22 May 2007 Posts: 70 Location: Putnam County, NY

I finally had some time to run through the gray scale calibration and after an hour or so of tweaking I am done for today..
I still see a pretty big blue level bump in the midrange IRE values. Is this correctable?

Also the luminance is a bit low. This should ride at around 2.2-2.5, correct? I don't know how to bump this up without increasing master black/white levels?

Please take a look at my result graphs and give some advice on how to correct. I didn't defocus blue any more yet, just messed with electronic controls for Kelvin and bright and contrast. I used the Get Gray DVD - much easier than Avia for this.
The image does look pretty good, however I can notice a bit of blue shift in the midrange. Nothing terrible, but after watching the gray boxes for about an hour I notice much more subtle color shifts than I did before. I don't know if this is such a good thing... Wink

Current values are:
Bright- 57 Contrast- 70
Kelvin (W/B) - R-43/58 G-52/65 B-68/27

Thanks again,
Dan

http://www.curtpalme.com/forum/album_page.php?pic_id=475
http://www.curtpalme.com/forum/album_page.php?pic_id=476

Mark_A_W · Posted: Wed Jun 06, 2007 10:13 pm Post subject:

Looks like you need to defocus blue LOTS. Either the defocus switch has not be set properly (focus blue electronically with switch OFF, then turn on), or it needs more.

And to change Gamma, it's easiest to change it in the source. I think you can sort of affect it using the white balance controls, but that's beyond me.

Mark_A_W · Posted: Wed Jun 06, 2007 10:13 pm Post subject:

Oh, and the calibrators I've seen typically try and leave Green at 50/50 and work around that.

danOO00 · Joined: 22 May 2007 Posts: 70 Location: Putnam County, NY

Thanks for the tips Mark. I will give the blue defocus a shot now.

danOO00 · Joined: 22 May 2007 Posts: 70 Location: Putnam County, NY

I was able to redo the grayscale last night and smoothed out that blue hump to an almost flat response across the 30-100 IRE range. I did have to defocus the blue on the deflection board a LOT. The dot pattern increased spot size on the internal pattern by almost 2X I estimate.

I watched some actual video afterwards Thumbs Up

, and the flesh tones and color balance looked much better than before. I didn't notice any blue fringing or lack of focus on video, but the internal PJ menus are all fringed in blue. I will watch a bit more content tonight as I was pressed for time last night and ended it where I was.

I am concerned that I had to defocus blue too much to get proper tracking. Is there a better method to set the amount of defocus needed?

jask · Joined: 17 Mar 2006 Posts: 10187 Location: kamloops BC

I do not want to belabour Marks point but you did adjust the blue focus with the switch in the off position correct?
I am suprised that it would require that much adjustment on the board, and now I am wondering how my picture would graph out...the blue looks great and I do not have any fringing on menu text.

danOO00 · Joined: 22 May 2007 Posts: 70 Location: Putnam County, NY

I had the defocus switch OFF and did an optical and electronic focus on blue. I then switched the defocus to ON and ran a grayscale calibration and still noticed a significant blue hump. Next I took Mark's advice and defocused blue more using the pot on the deflection board while the defocus switch was still ON. (correct?) It took quite a bit of defocus to track blue almost linear across the 0-100IRE range.
The blue fringig is now slightly noticeable on video. I think I may try and back off the defocus some and try calibrating grayscale again. I also lowered contrast some to around 60 and bumped the master brightness up around 70. The image has much more shadow detail and color accuracy but does look like it is missing some punch compared to when I had the contrast up higher. I guess there is a trade-off with this set between punch and color accuracy? Maybe I need to spend some more time adjusting.....

Thanks, and I will update this thread with graphs and values next time.