Digital Projection Projector M-Vision 930 3D Series User Manual

page 73
Reference Guide
THE DMD™
Depending on the voltage polarity applied, each mirror will either tilt \
to the left to produce a bright pixel or to the right for a dark pixel. \
When 
light is applied to the complete DMD™, only the light redirected from\
 a mirror tilting to the left is projected.
1Projection lens
2Incoming light from the illumination module
3Mirror element tilted to the right
4Mirror element tilted to the left
5Reflected light, left tilt
6Light dump
7Reflected light, right tilt
The...

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Reference Guide
CHOOSING A LENS
Choosing A Lens
A number of lenses are available. Which lens you choose depends on the sc\
reen size, image aspect ratio, throw distance and light output.
The following table shows all available lenses in order of their throw ratios:
Throw ratiosThrow distance rangeLens extension
0.84 - 1.03 : 1 zoom lens1.5 - 10 m (4.9 - 32.8 ft)98.5 mm
1.56 - 1.86 : 1 zoom lens2 - 12.4 m (6.6 - 40.7 ft)15.4 mm
1.85 - 2.40 : 1 zoom lens2.5 - 15.9 m (8.2 - 52.2 ft)15.4 mm
2.40 -...

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Reference Guide
CHOOSING A LENS
Basic calculation
Identify the required lens by calculating the throw ratio.
A throw ratio is the ratio of the throw distance to the screen width:
Throw distanceScreen width
Throw ratio =
1. Use the formula above to obtain the required throw ratio.
2. Match the throw ratio with a lens from the table below:
Throw ratiosThrow distance range
0.84 - 1.03 : 1 zoom lens1.5 - 10 m (4.9 - 32.8 ft)
1.56 - 1.86 : 1 zoom lens2 - 12.4 m (6.6 - 40.7 ft)
1.85 - 2.40 : 1 zoom...

page 76
Reference Guide
CHOOSING A LENS
Basic calculation example
1. Calculate the throw ratio using the formula.
Your screen is 3.5 m wide and you wish to place the projector 
approximately 6.8 m from the screen. The throw ratio will then 
be
  
6.8
3.5 = 1.94
2. Match the result with the lens table.
The lens matching a throw ratio of 1.94 is the 1.85 - 2.40 : 1 
zoom lens.
3. Check whether the lens covers the required throw distance. 
The range quoted for the 1.85 - 2.40 : 1 zoom lens is 
2.5 - 15.9 m....

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Reference Guide
CHOOSING A LENS
Full lens calculation
Introducing TRC
The choice of lens will affect the image size and will address discrepancies between the 
DMD™ resolution and the source.
When an image fills the height of the DMD™ but not the width, it uses less than 100% of 
the DMD™ surface. A lens chosen using the basic formula may produce an image that is 
considerably smaller than the actual screen.
To compensate for loss of screen space in such situations, you need to in\
crease the...

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Reference Guide
CHOOSING A LENS
Calculating TRC
To calculate TRC, use the following formula:
1.6 (DMD™ aspect ratio)Source aspect ratio
TRC =
TRC table
Alternatively, you can save time by referencing the following table, which shows the TRC value for some popular image formats:
2.35:1 (Scope), 1920 x 817 pixelsTRC < 1, not used
1.85:1 (Flat), 1920 x 1037 pixelsTRC < 1, not used
1.78:1 (16:9), 1920 x 1080TRC < 1, not used
1.66:1 (Vista), 1792 x 1080 pixelsTRC < 1, not used
1.6:1 (16:10), 1728 x...

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Reference Guide
CHOOSING A LENS
Calculating the throw ratio with TRC
1. For TRC > 1, amend the basic throw ratio formula as follows:
Throw distance
Screen width  x TRC
Throw ratio =
2. Once a throw ratio is established, identify the matching lens from the t\
able:
Throw ratiosThrow distance range
0.84 - 1.03 : 1 zoom lens1.5 - 10 m (4.9 - 32.8 ft)
1.56 - 1.86 : 1 zoom lens2 - 12.4 m (6.6 - 40.7 ft)
1.85 - 2.40 : 1 zoom lens2.5 - 15.9 m (8.2 - 52.2 ft)
2.40 - 4.00 : 1 zoom lens4 - 26.6 m (13.1 -...

page 80
Reference Guide
CHOOSING A LENS
Full lens calculation example
Your screen is 3.5 m wide; you wish to place the projector 
approximately 6.8 m from the screen. The source is 4:3.
1. Calculate TRC as follows:
1.6
1.33
TRC = = 1.2
2. Calculate the throw ratio:
6.8
3.5 x 1.2
Throw ratio = = 1.62
3. Find a match in the lens table.
The table shows that the matching lens is the 1.56 - 1.86 : 1 
zoom lens.
4. Check whether the lens covers the required throw distance.
The range quoted for the 1.56 - 1.86...

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Reference Guide
SCREEN REQUIREMENTS
Screen Requirements
Fitting the image to the DMD™
If the source image supplied to the projector is smaller than the DMD™ resolution, the image will not fill the DMD™. The following examples 
show how a number of common formats may be displayed.
WUXGA images displayed full width
Notes
full width = 1920 pixels
2.35:1(Scope) 
 =  817 pixels
1.85:1 
 = 1037 pixels
16:9 = 1.78:1  
= 1080 pixelsfull height  
= 1200 pixels
   
Digital Projection M-Vision 930 Series...

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Reference Guide
SCREEN REQUIREMENTS
WUXGA images displayed with a height of  1080 pixelsNotes
4:3 = 1.33:1 = 1440 pixels
full height 
= 1200 pixels
1.66:1 (Vista) = 1792 pixels 16:10 = 1.6:1 = 1728 pixels
max possible  image height 
 
= 1080 pixels
full width = 1920 pixels
   
Digital Projection M-Vision 930 Series 
Rev C Februar y 2015