Screen Dimension Calculator Help

SMART Calibration
Step 1: Build A Detector
Step 2: Set Up Detector
Step 3: Test Photocells
Step 4: Record Current Projector Settings
Step 5: Detector Calibration Run
Step 6: Bias Improvement
Step 7: Gain Improvement
- Results (No Filter)
Step 8: Adding A Filter
- Results (Filter)

The Augustine Theater Experience
Sharp XV-Z9000U SMART Calibration

Step 2: Set Up Detector

Relevant SMART web page: http://home.pacbell.net/steve367/buildit.html

Materials & Tools List Cost Notes
Alligator-clip adapters 2.69 Radio Shack #270-354A
Avia DVD  
Cadmium-sulfide photocells 2.49 Radio Shack #276-1657 contains five assorted photocells
Digital multimeter 59.99 Radio Shack #22-805. I bought this one because it can be connected to a computer via an RS-232 serial cable and used with Eric Huff's ColorCatch program. (See the bottom of the SMART web page referenced above.) I don't know if I'll use ColorCatch, but with the 22-805 I can if I need to.

The SMART web site recommends the 22-802 multimeter. It also says whatever multimeter you choose needs to measure a maximum of 10M Ohms. The 22-802 only measures to 4M. So I thought better safe than sorry; the 22-805 measures to 40M.
Electrical tape 0.47
Speaker cable   Any gauge. I used 12 feet of some 14 gauge I had lying around.
Tripod  
Wire crimpers   I think that's what they're called.
Wire stripping tool  

Steps

  1. Put the pipe on the tripod mount and wrapped a piece of electrical tape around it.
     
  2. Chose a photocell from the Radio Shack five-pack and slipped its two leads through the holes in the end cap. Didn't secure the photocell because it may not be suitable for SMART. May have to test several.
     
  3. Placed the end cap in the end of the pipe. Didn't secure it too tightly; it's hard to get out.
     
  4. Turned on my projector and displayed the AVIA DVD 100 IRE Window pattern. From the main menu:
     
    1. Advanced AVIA
    2. Video Test Patterns
    3. Gray Scale & Levels
    4. Window Patterns
    5. 100 IRE Window
    6. Hit Pause on my DVD remote, otherwise the DVD will move on to the next pattern after several seconds.
       
  5. Placed the tripod in front of the screen and positioned the detector inside the 100 IRE Window. The distance between the projector and the photocell must remain constant for all measurements.
     
  6. Adjusted the detector's tilt so the light from the projector hit the photocell square. Did this by adjusting the detector so no shadows were hitting the end cap at the end of the pipe.

    Not square: Square:

Connected The Digital Multimeter

  1. Put a battery in the multimeter, connected the supplied leads, and connected the alligator-clip adapters to the leads. (Ignore the silver pen in the picture. I didn't use it.)
     
  2. Stripped both ends of the speaker wire.
     
  3. Clipped the alligator clips to one end of the speaker wire.
     
  4. Connected wire crimpers to the other end of the speaker wire. Crimped the wire for a solid connection. Used crimpers meant for 22-16 AWG wire, but my 14 AWG wire fit -- barely.
     
  5. Slid the crimpers over the photocell leads. Did NOT crimp them down. May need to test several photocells. Made sure the photocell was facing the projected light.
     
  6. Turned on the multimeter and set it to measure resistance/Ohms.
     
  7. Turned out the lights and took a measurement of the 100 IRE Window: 2.205K.
     
  8. Stood between projector and detector. Multimeter should measure more resistance, and it did: 75.2K. (The meter sure took a while to settle. Went from 74 to 76 and everywhere in-between.)

Next Step >>


Augustine Central