Technology Transitions Workshop

Camera Selection and Testing

Technology Transitions Workshop

Resolution

• What resolution is needed?– Application dependant– Footwear and tire impressions

Technology Transitions Workshop

Camera Resolution

• Film or Sensor• Lens• Final image

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

Lenses

• Quality of manufacture• Focal length

Technology Transitions Workshop

Final image

• Print size• Printer capability

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

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

Technology Transitions Workshop

Final Images

• Printed by photo processing lab• Center target printed 65% of natural size due

to limitations of processing lab

Technology Transitions Workshop

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

Technology Transitions Workshop

Lens Comparison

EOS 20D

13.74 13.74 13.7414.04

15.72 15.7215.35 15.35 15.35

0.00

5.00

10.00

15.00

S M L

Image size

LP

M

EF 24-85 lens

EFS 17-85 lens

EF 24-105 lens