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icon5.gif  Calibration Procedures of a CRT Front Projection System with a DVD Player Fri, 09 December 2005 07:42 Go to next message
acykiu is currently offline acykiu
Messages: 47
Registered: January 2005
Location: HK
Junior Member
Patrick,
Gordon,

I've just acquired a set of Spyder2Pro Studio 2.0 and would like to do a calibration of my FP system. Grateful if you could take a look at the following steps to see whether they're in order:-

Setup description
Barco Cine 7 CRT projector - ceiling mounted

Pioneer DV-S969AVi (SDI) → Lumagen Vision Pro HDP RGBHV) → Barco Cine 7

Output resolution is 1280x720 at 59.4Hz/71.93Hz (NTSC) or 1024x768 at 75Hz (PAL).

Room has no black treatment. Walls are matt beige in color, ceiling is matt white in color, and floor is light maple. Wooden furniture in light maple/cherry/beech; orange sofa. Occassional light leakage at the sides of light-shielded curtains.
Screen is a 84” 4:3 Stewart Ultramatte 150 (1.5 gain).

Procedures
Brightness and Contrast
1. Make sure that DVDP is set to 7.5 IRE instead of 0 IRE.

2. Using HiVi Cast, set brightness so that the 0-1-2 Black bars are just distinguishable.

3. Using HiVi Cast, turn up contrast so that the 100-99-98 White bars are still distinguishable.

4. Using AVIA’s steps, needles and pulse pattern, check that the top white block does not bloom; is visually in sequence in light level with the blocks below it; and that the vertical lines show no distortion from PSU overdrive. Else, turn down the contrast.

5. Make sure that the scanlines at 80 / 90 IRE patterns are just distinguishable, and that they are just overlapping a hair at 100 IRE. The slight softening in the brightest areas will give a more “film-like” experience.

6. Repeat brightness and contrast settings till both are set correctly.


Grayscale
7. Position the Spyder2 probe (LCD baffle removed) on a tripod, about 8”-12” from the screen and facing it, below the centerline and angled up at 15-20 degrees, so that it is measuring the center of the screen and not its own shadow.

8. Connect Spyder2 to a PC. Start a CRT monitor calibration and wait until the sensor initializing stage has been completed. Then, cancel the calibration process and open the colorimeter application under “Tools” (so that Spyder2 is not in LCD mode).

9. Throw up the AVIA 100 IRE window pattern. Take a reading using the PC, and enter the xyY data into the spreadsheet made by "Radar" in AVS Forum (use the AVIA tab in box K3 for corrected values, and choose D65 in box K6).

10. Proceed to take readings at the 90 / 80 / 70 / 60 / 50 / 40 / 30 / 20 / 10 / 0 IRE window patterns (readings at 10 IRE and 0 IRE are junk as the Spyder2 is not sensitive enough for CRT projection at these levels).

11. Throw up the 50 IRE window pattern again, and adjust the Colr/ColrRed/ColrGrn values of the Lumagen scaler to make the RGB curves meet up as close to the target curve at that point as possible, with a low DeltaE value (aiming for 4 or less).

12. Enable the service menu of the Lumagen scaler by pressing “Menu 0 9 1 0”. Then throw up the remaining 20 – 40 and 60 – 100 IRE window patterns, and adjust the CTEMP values so that the RGB Gamma curves meet up as close to the target as possible, with low DeltaE values (aiming for 4 or less).

13. Go back and check the contrast and brightness settings again as the RGB and CTEMP adjustments would affect the settings.

14. Repeat the process until the 20 – 100 IRE are all as close to D65 as possible, aiming for a DeltaE of 4 or less.

Many thx. in advance.

Other members are also welcomed to contribute.

Smile

AK
Re: Calibration Procedures of a CRT Front Projection System with a DVD Player Thu, 15 December 2005 01:17 Go to previous messageGo to next message
jim_peterson
Messages: 1378
Registered: November 2004
Location: Beaverton Oregon, USA
Lumagen Expert
Lumagen Guru
AK:

I’ll take a shot at this, but this level is really beyond the scope of a posting. I’m not familiar with the specifics of your probe, but what you have in your post seems like a reasonable approach. I do have a few comments.

The first thing I would suggest is to paint your ceiling and walls a dark neutral color using flat paint. If you can’t paint everything, at least try to get permission to paint the wall with the screen on it as dark a neutral color as acceptable to other family members. Barring this can you paint a dark “frame” of paint around the screen. The larger the better, of course. Any of these should be a big improvement verses beige and white.

For setting contrast I use the internal Lumagen pattern and the projectors black and contrast controls. Then I adjust for differences between sources using the Lumagen controls.

For selecting the best resolution, I cover the Red and Blue guns and put up the Lumagen every-other horizontal line pattern. This allows one to check a number of resolutions without converging each one. Generally the contrast in the projector should be around its 50% point. Many projectors start to bloom slightly above this point, which reduces resolution.

Pointing the color probe at the screen is problematic given the rainbow effect it has on the colors and the reduction in available light for the measurement. I use a Progressive Labs probe that has an offset table for most common screens so I can point the probe at the projector to get plenty of light for accurate readings at low light levels and still have a very accurate result. This is a much better approach.

Even if you don’t have offsets for your probe, I suggest calibrating at 100 IRE with the probe facing the projector and then checking the reading by pointing the probe at the screen. It should be pretty close for most screens. You could tweak the values while pointing at the screen and the check pointing at the projector and figure out an offset value from that. Or if it is not too far off, just point it at the projector and be a little off. If you are at say 6800K instead of 6500K you might find you can not even visually see a difference while watching real material. My point is just that you are not going to be getting good consistant readings pointing at the screen, especially at low IRE values. A consistent color temp that is slightly off from pointing at the projector is better than the inconsistent readings you will get pointing at the screen.

If you are off the D65 point, make sure you are +blue and not +green or +red. No one seems to mind a slightly +blue image, but many dislike either +green or +red.

Of course, these are my opinions and others may disagree.



Jim Peterson
Lumagen

[Updated on: Thu, 15 December 2005 01:22]

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icon14.gif  Re: Calibration Procedures of a CRT Front Projection System with a DVD Player Thu, 15 December 2005 07:26 Go to previous message
acykiu is currently offline acykiu
Messages: 47
Registered: January 2005
Location: HK
Junior Member
Woww! Thx. Jim, for the advices, in particular, the idea of an offset table. Will create one for the Stewart Ultramatte 150 screen with the Spyder2.

Re-painting the walls/ceiling is, I'm afraid, not an option ... WAF ... but my electric screen is hanging above a big bay window with a dark blue curtain (with a little fancy patterns and light-shielding backing), will see if I can change into pure dark grey.

BTW, can Cyan, Magenta and Yellow test patterns be added so that users can do hue adjustments as well?

Lastly, eagerly looking forward to Lumagen's new Radience series. And pls. do consider releasing a basic/lite version so that existing HDP owners could upgrade while keeping their processor (mainly for environmental reasons).

Many thx. again.

Very Happy

AK
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