1. Camera Selection and Testing

2. Resolution What resolution is needed? Application dependant
Footwear and tire impressions

3. Camera Resolution
Film or Sensor
Lens
Final image

4. 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.

5. Digital Camera Sensors
Pixel Density
Light sensitivity
Physical size

6. Lenses
Quality of manufacture
Focal length

7. Final image
Print size
Printer capability

8. Testing Line resolution Edmunds Scientific Resolution chart
24X36 inch poster
Multiple USAF resolution targets
Center target used to determine line pairs resolved per millimeter

9. 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

10. 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

11. Final Images Printed by photo processing lab
Center target printed 65% of natural size due to limitations of processing lab

12. 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

13. 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.

14. 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

15. EOS 1Ds to Film

16. EOS 20D to Film

17. EOS 1Ds to 20D

18. EOS 1Ds to 20D

19. Lens Comparison

20. Lens Comparison