Technology Transitions Workshop
Resolution
• What resolution is needed?– Application dependant– Footwear and tire impressions
Technology Transitions Workshop
Film or Sensor Size
• Physical size of film or sensor– Resolution relative to object size
• Larger film or sensor increases final resolution.
• 35mm film generally accepted as having sufficient resolution for Footwear impression documentation.
Technology Transitions Workshop
Digital Camera Sensors
• Pixel Density• Light sensitivity• Physical size
Technology Transitions Workshop
Testing
• Line resolution• Edmunds Scientific Resolution chart
– 24X36 inch poster– Multiple USAF resolution targets– Center target used to determine line pairs
resolved per millimeter
Technology Transitions Workshop
Cameras
• Canon EOS Elan 35mm film• Canon EOS 1Ds Mark 2
– Sensor size same as 35mm film– 16.7 MP sensor
• Canon EOS 20D– Sensor smaller than 35mm film (1.6X)– 8.2 MP sensor
Technology Transitions Workshop
Lenses
• Canon EF 24-85mm• Canon EFS 17-85mm (20D only)• Canon EF 24-105mm• 50mm focal length used for all testing
– EOS 20D set at 50mm equivalent
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Final Images
• Printed by photo processing lab• Center target printed 65% of natural size due
to limitations of processing lab
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Procedure
• Edges poster filled frame (24X36 inches)– 11X17 inch area also captured with
EOS 20D• All digital images captured with jpeg format• Four ISO settings, three file sizes, and three
compression settings used with EOS 1Ds Mark 2
• One ISO setting, three file sizes, and one compression setting used with EOS 20D
Technology Transitions Workshop
Procedure (cont.)
• 35mm film results compared to EOS 1Ds Mark 2 results.
• EOS 1Ds results compared to EOS 20D results.
• Lens comparison images of 11X17 poster area captured with both EOS 1Ds and EOS 20D.
Technology Transitions Workshop
Results
• EOS 1Ds met or exceeded Film at several settings
• EOS 20D met EOS 1Ds resolution at its highest setting for the 11X17 poster area
• Different lenses will affect the resolution of captured images
Technology Transitions Workshop
EOS 1Ds Mark II Camera at 800 ISO
0.32 0.60 1.10 0.85 1.64 3.12 2.80 5.5010.00
41.18
30.0837.96 37.96
47.75 47.7553.48 53.48 53.48
41.18 42.49
0.0010.0020.0030.0040.0050.0060.00
S (1) S (5) S (10) M (1) M (5) M (10) L (1) L (5) L (10)
200Film
400Film
Format (1, 5, 10 JPEG Compression)
LP
M File Size (MB)
LPM
EOS 1Ds to Film
Technology Transitions Workshop
Full poster EOS 20D Vs. FilmEF 24-85 mm Lens
31.0034.69 34.69 34.69
41.18 41.18
0.00
10.00
20.00
30.00
40.00
50.00
100 200 400 800
ISO
LP
M 20D
Film
EOS 20D to Film
Technology Transitions Workshop
EOS 1Ds vs EOS 20D EF 24-85mm lens
13.41 13.41 13.4113.74 13.74 13.74
0.00
5.00
10.00
15.00
S M L
Image size
LP
M 1Ds
20D
EOS 1Ds to 20D
Technology Transitions Workshop
EOS 1Ds to 20D
1Ds vs 20D EF 24-105mm lens
14.40 14.40 14.4015.35 15.35 15.35
0.00
5.00
10.00
15.00
S M L
Image size
LP
M 1Ds
20D
Technology Transitions Workshop
EOS 1Ds Mark II
13.41 13.41 13.4114.40 14.40 14.40
0.00
5.00
10.00
15.00
S M L
Image size
LP
M EF 24-85 lens
EF 24-105 lens
Lens Comparison