Drop Video Mastery Slides
Vernier Video Analysis Lab Prep
Grade 9 Physics • Created with Lenny.com
Filming the Perfect Drop
High-precision data starts behind the camera. Learn the 4 golden rules of video capture before tracking pixels.
Coplanar Scale
Meterstick on drop line
Zero Shake
Fixed iPad position
Perpendicular View
Eliminate parallax angles
Rule 1
Meterstick Must Be Coplanar
Scale Calibration
What is "Coplanar"?
The meterstick and the falling ball must be at the exact same distance from the iPad camera lens.
The Error If You Don't
Objects closer to the lens look bigger. If your meterstick is closer than the ball, your scale calibration will be distorted and your calculated acceleration will be inaccurate!
Side View: Vertical Scale & Motion Plane
TARGET MOTION PLANE 0 1 Meterstick Ball Drop Path iPad Camera Distance (d) Same distance to both!
Pro Tip: Tape the meterstick flat against the wall, and drop the ball just 2–3 inches in front of that same wall! 1:1 Calibration
Rule 2
Keep the iPad Parallel to Motion
Perspective Control
CORRECT SETUP 90° Right Angle
Vertical Drop Plane iPad Screen Exact 90°
The camera points straight on at the drop midpoint. iPad face is vertical, perfectly parallel to the wall.
AVOID TILT & ANGLE Parallax Distortion
Tilted / Angled Severe Foreshortening!
Tilting up or down causes perspective compression. Distances at the top look smaller than distances at the bottom!
Height check: Hold or mount the iPad at the middle of the drop height (chest level, not floor or ceiling). Center Lens
Rule 3
Zero Camera Movement & Clear Focus
Stability & Motion Clarity
Fix The Camera
Avoid handheld filming. Rest the iPad on a lab bench stand, box, or use a steady tripod.
Why: Hand wobble gets tracked as false ball velocity in Vernier!
Use 30 or 60 fps
Film in standard Video mode at 30 or 60 fps for reliable timing and easy frame stepping.
Frame counts: 60 fps gives ~30 frames; 30 fps gives ~15 frames!
Ample Lab Lighting
Fast motion in dim light causes motion blur. Keep overhead lights on and illuminate the drop zone.
Crisp edges: You must click the center of the ball in every frame!
Partner technique: If holding by hand, pin both elbows firmly against a lab table surface for stability. Lock Elbows
Rule 4
Framing & Clean Drop Execution
Field of View
Camera Viewfinder Framing REC
Drop Path
Ground in Frame
1.0 m Scale
0
1m
Entire drop height + meterstick + landing spot visible!
1. Open Fingers, Don't Push!
Hold ball between thumb and finger. Pull fingers apart smoothly. Never flick or spin the ball.
2. High Contrast Background
Dark ball against a light wall, or bright tennis ball against a dark backdrop. Avoid visual clutter!
3. Record 1s Before Release
Hit record, pause 1 second, then drop. Let it bounce before stopping. You can trim clips in Vernier.
Hand visibility: Keep fingers above or behind the release point so they don't block the ball! Unobstructed
Action Checklist
Pre-Flight Check: Before You Drop
Ready to Record
1
Coplanar Alignment
Meterstick is in the same vertical plane as the drop path (tape flat to the wall).
2
Perpendicular & Level
iPad is vertical and centered at mid-drop height. Optical axis forms a 90° angle with wall.
3
Stationary Camera
iPad is rested on a stand or braced firmly against the lab bench. No hand wobble.
4
Video Mode: 30 or 60 fps
Use standard Video mode (30 or 60 fps). Start recording, drop cleanly, wait for bounce, then stop.
Ready? Head to your lab stations, set your distances, and take your first test take!
Discover Freefall Acceleration
