CFP Technology & Tools 3 — Questions and Answers
Question 1: Infrared (IR) photography is most useful in forensic work for which application?
- Revealing gunshot residue patterns and obliterated writing on dark fabrics or documents (Correct answer)
- Measuring the distance between evidence items
- Improving autofocus speed in daylight
- Reducing file sizes for court exhibits
Correct answer: Revealing gunshot residue patterns and obliterated writing on dark fabrics or documents
IR penetrates or differentiates materials like GSR, inks, and blood on dark surfaces that look uniform in visible light.
Question 2: Ultraviolet (UV) reflectance photography is commonly used to document which type of evidence?
- Bite marks and healed bruising on skin (Correct answer)
- Bullet trajectories through walls
- Tire tread depth measurements
- Vehicle identification numbers
Correct answer: Bite marks and healed bruising on skin
UV reflectance reveals surface-level skin injuries such as bite marks and old bruises that are faint in visible light.
Question 3: A photographer uses focus stacking software on a series of cartridge case images. What problem does this technique solve?
- Shallow depth of field at high magnification (Correct answer)
- Incorrect white balance
- Sensor dust spots
- Lens vignetting at wide apertures
Correct answer: Shallow depth of field at high magnification
Focus stacking combines multiple images focused at different depths to produce one image sharp throughout, overcoming macro depth-of-field limits.
Question 4: Which storage practice best preserves the integrity of original digital images from a crime scene?
- Write-protect and archive the original files unaltered, working only on duplicates (Correct answer)
- Edit originals directly to save storage space
- Store the only copy on the camera's memory card indefinitely
- Convert all originals to compressed JPEGs before archiving
Correct answer: Write-protect and archive the original files unaltered, working only on duplicates
Preserving unaltered originals and performing all processing on copies maintains the evidentiary chain and authenticity.
Question 5: What does a hash value (e.g., MD5 or SHA-256) generated at the time of image acquisition provide?
- A digital fingerprint verifying the file has not been altered (Correct answer)
- Automatic image sharpening
- GPS coordinates of the scene
- Compression of the image for email
Correct answer: A digital fingerprint verifying the file has not been altered
A cryptographic hash uniquely identifies the file's exact contents, so any later change produces a different hash and proves alteration.
Question 6: Which tool allows a forensic photographer to capture an entire room as a navigable 360-degree record?
- A spherical panoramic camera or laser scanning system (Correct answer)
- A macro bellows unit
- A teleconverter on a telephoto lens
- A slave flash trigger
Correct answer: A spherical panoramic camera or laser scanning system
Spherical panoramic cameras and 3D laser scanners produce immersive full-scene documentation used for virtual walkthroughs.
Question 7: When using electronic flash in a smoky or dusty scene, what problem should the photographer anticipate?
- Light scatter and backscatter reducing contrast and creating bright particle artifacts (Correct answer)
- The flash will not fire in particulate air
- Colors will shift to infrared
- Shutter speed will automatically increase
Correct answer: Light scatter and backscatter reducing contrast and creating bright particle artifacts
Airborne particles reflect flash light back toward the lens, washing out the image and creating bright spots.
CFP Technology & Tools 3
Infrared (IR) photography is most useful in forensic work for which application?