Last updated: June 1st, 2007 (test pattern and spreadsheet now available for download)
Note: This is an updated thread based on: http://www.avsforum.com/avs-vb/showthread.php?t=781060 The older thread was obsoleted due to the inclusion of additional explanations and dynamic contrast results which couldn't be fit into the earlier thread.
The first 6 posts of this thread contain a detailed explanation of the test patterns and methodology that is being used as part of the AVS Contrast Project. The contrast framework that is described here was applied to two projectors, one native and one with a dynamic iris (JVC RS-1 and Sony VW50). These first 6 posts are intended to be used as an example of the type of information that can be extracted from these simple measurements. It is hoped that more projectors will be measured and their results added to the AVS Contrast Project. The results of this ongoing work can be found after the 6 posts of this initial discussion (starting at post 8 or thereabouts).
Also, please realize that while considerable care has gone into the methodologies, measurements, calculations, and graphs that are contained here, the accuracy of the results cannot be guaranteed and are subject to variances in measurements, accuracy of sensors and unit to unit variance. The information presented here is desiged for rough comparisons only.
This is a work in progress, check back often for additional results and information!
Index
Part I - Overview
Purpose
Terminology
Background
- Sequential On/Off Contrast and ANSI Contrast
- Dynamic and Static Intra-Image Contrast
- What causes Contrast?
- Contrast as a function of Luminance
- Theoretical vs Measured Intra-Image Contrast
Test Pattern Suites - Static Intra-Image Test Patterns and Dynamic Intra-Image Test Patterns
Part II - Static Intra-Image Contrast Example (JVC RS-1 and Sony VPL-VW50)
RS-1 Intra-Image Contrast
RS-1 Contrast vs Throw
Maximum Intra-Image Contrast defined
Usefulness of Maximum Intra-Image Contrast as a Metric
VW50 Maximum Intra-Image Contrast (Iris off and Iris 1)
Examination of Intra-Image white and black levels
Constancy of White Examined
RS-1 White Levels
VW50 White Levels (Iris Off and Iris 1)
Constancy of Black Levels
RS-1 black level vs luminance
VW50 black levels vs luminance
VW50 Iris 1 vs RS-1 relative black level comparison
Part III - Dynamic Intra-Image Contrast Example (JVC RS-1 and Sony VW50)
Dynamic intra-image contrast test patterns
Sony VW50 Dynamic Contrast Examined
Intra-Image Contrast as a combination of static and dynamic contrast mechanisms
Sony VW50 Relative and Absolute Luminance - Iris 1 and Iris Off comparison
Sony VW50 Dynamic Gamma Examined
Part III (Continued)
Low APL greyscale test pattern
Sony VW50 Intra-Image Contrast and relative luminance - Iris 1 vs Iris 2 comparison
JVC RS-1 Intra-Image contrast examined
Source Material with a Dynamic Iris Projector
Sony VW50 Shadow Detail Examined
JVC RS-1 Examined
Examination of Theoretical Parameters of a VW50
Improvement factor of VW50 Iris 1 over Iris Off as a function of stimulus
Part III (Continued)
Comparison of RS-1 and VW50
JVC RS1 with a Sony VW50 DI - A Theoretical Treatment
Part IV - Summary / Acknowledgements / References
Dynamic Iris Performance Summarized
Final Summary
Acknowledgements
AVS Contrast Project Database
AVS Contrast Project Database
Static Contrast Test Patterns
Dynamic Contrast Test Patterns.
AVS Contrast Project - Static Intra-Image Contrast Results
AVS Contrast Project - Dynamic Intra-Image Contrast Results
Contrast Discussion Starts Here
Note: This is an updated thread based on: http://www.avsforum.com/avs-vb/showthread.php?t=781060 The older thread was obsoleted due to the inclusion of additional explanations and dynamic contrast results which couldn't be fit into the earlier thread.
The first 6 posts of this thread contain a detailed explanation of the test patterns and methodology that is being used as part of the AVS Contrast Project. The contrast framework that is described here was applied to two projectors, one native and one with a dynamic iris (JVC RS-1 and Sony VW50). These first 6 posts are intended to be used as an example of the type of information that can be extracted from these simple measurements. It is hoped that more projectors will be measured and their results added to the AVS Contrast Project. The results of this ongoing work can be found after the 6 posts of this initial discussion (starting at post 8 or thereabouts).
Also, please realize that while considerable care has gone into the methodologies, measurements, calculations, and graphs that are contained here, the accuracy of the results cannot be guaranteed and are subject to variances in measurements, accuracy of sensors and unit to unit variance. The information presented here is desiged for rough comparisons only.
This is a work in progress, check back often for additional results and information!
Index
Part I - Overview
Purpose
Terminology
Background
- Sequential On/Off Contrast and ANSI Contrast
- Dynamic and Static Intra-Image Contrast
- What causes Contrast?
- Contrast as a function of Luminance
- Theoretical vs Measured Intra-Image Contrast
Test Pattern Suites - Static Intra-Image Test Patterns and Dynamic Intra-Image Test Patterns
Part II - Static Intra-Image Contrast Example (JVC RS-1 and Sony VPL-VW50)
RS-1 Intra-Image Contrast
RS-1 Contrast vs Throw
Maximum Intra-Image Contrast defined
Usefulness of Maximum Intra-Image Contrast as a Metric
VW50 Maximum Intra-Image Contrast (Iris off and Iris 1)
Examination of Intra-Image white and black levels
Constancy of White Examined
RS-1 White Levels
VW50 White Levels (Iris Off and Iris 1)
Constancy of Black Levels
RS-1 black level vs luminance
VW50 black levels vs luminance
VW50 Iris 1 vs RS-1 relative black level comparison
Part III - Dynamic Intra-Image Contrast Example (JVC RS-1 and Sony VW50)
Dynamic intra-image contrast test patterns
Sony VW50 Dynamic Contrast Examined
Intra-Image Contrast as a combination of static and dynamic contrast mechanisms
Sony VW50 Relative and Absolute Luminance - Iris 1 and Iris Off comparison
Sony VW50 Dynamic Gamma Examined
Part III (Continued)
Low APL greyscale test pattern
Sony VW50 Intra-Image Contrast and relative luminance - Iris 1 vs Iris 2 comparison
JVC RS-1 Intra-Image contrast examined
Source Material with a Dynamic Iris Projector
Sony VW50 Shadow Detail Examined
JVC RS-1 Examined
Examination of Theoretical Parameters of a VW50
Improvement factor of VW50 Iris 1 over Iris Off as a function of stimulus
Part III (Continued)
Comparison of RS-1 and VW50
JVC RS1 with a Sony VW50 DI - A Theoretical Treatment
Part IV - Summary / Acknowledgements / References
Dynamic Iris Performance Summarized
Final Summary
Acknowledgements
AVS Contrast Project Database
AVS Contrast Project Database
Static Contrast Test Patterns
Dynamic Contrast Test Patterns.
AVS Contrast Project - Static Intra-Image Contrast Results
AVS Contrast Project - Dynamic Intra-Image Contrast Results
Contrast Discussion Starts Here