Inexpensive Very High Speed Photography For Mechanics - PowerPoint Presentation

Slide1

Inexpensive Very High Speed Photography For Mechanics

Funded by the Early Undergraduate Research Program

By: Melissa

Chudyk

, Steven

Dutter

, and Steven

Wilser

Advisor: Daniel L.

MacIsaacSlide2

SetupSlide3

The Time Machine

This is The Time Machine, a device created by Brian Mumford. The purpose of The Time Machine is high speed, and time lapsed photography.

The Time Machine consists of a 16 character LCD screen, five push buttons, and a sensitivity control. There are also four jacks at the top end of the machine. They are the flash output, sensor input, shutter output, and AC adaptor.

The Time machine has ten modes of operation that you can use. All of the modes can be used for different photographing situations.Slide4

Balloon Popping, 1

st

Attempt using microphone to trigger flashSlide5

Balloon Popping, with flour using microphone to trigger flashSlide6

Flash Modification

Before

AfterSlide7

Resistor trials

1k Ohm resistor,

Too Dark

10k Ohm resistor,

Too LightSlide8

Resistor Trial Cont.

4.7k Ohm resistor,

Not too dark or lightSlide9

Popping water balloons

-Used 4.7k Ohm resistor in flash

-Microphone sensor was setup near balloon to trigger flashSlide10

Multiple Exposure of Ping Pong Ball

-1k Ohm resistor

-Left shutter open, set flash to fire 10 times

-Rolled ping pong ball off ramp in order to get this motion

-microphone sensor set off flash when ball first hit groundSlide11

Dropping Water Balloons using a Delay

-Using 4.7k Ohm resistor in flash

-When balloon hit ground the microphone sensor triggered the flash

-All Balloons were dropped from same height

-.01 second delay usedSlide12

Balloon Droppings Cont.

.02 Second Delay

.03 Second DelaySlide13

Balloon Dropping Cont.

.04 Second delay

.05 Second delaySlide14

Capturing Pellet Mid-Flight

-Used ballistics sensor to trigger flash

-used 680 Ohm resistor

-positioned flash as close as possibleSlide15

Capturing Pellet Trials

270 Ohm Resistor,

Too Dark and Blurry

820 Ohm Resistor,

Too BlurrySlide16

Money Shot

-Captured pellet inside of water balloon

-

4.7k Ohm resistor

-Ballistic sensor triggered flashSlide17

Simple Kinematics

Length of gun barrel = 0.397 m

Length of barrel and sensor = 0.58 m

Velocity of pellet determined by sensor = 198 m/s

Mass of pellet = 7.5 g = 0.0075 kg

Distance from barrel to backstop = 6.12 m

Speed of sound = 340.29 m/s

Acceleration of pellet in

barrel:

Force exerted on pellet:Slide18

Simple Kinematics Cont.

The time sound takes to get to the backstop

:

Time between sound hitting backstop and

pellet hitting

backstop, determined from

LabView

data

= 0.028 s = 28

ms

Time for pellet to hit backstop = the time of

sound to

hit + the time between = 0.018 s + 0.028

s=

0.046 s = 46 ms

Average velocity of pellet

:

Time pellet is in barrel using acceleration in barrel:

Time pellet is in barrel using length of barrel:Slide19

Visit our website at:

http://physicsed.buffalostate.edu/EURP08Slide20

Reference

Winters, Loren (1996). A Tutorial in High-Speed Photography with Electronic Flash. Retrieved July 3, 2008, from

http://www.hiviz.com

Mumford, B. The time Machine. Retrieved June 2, 2008, from The Time Machine Camera Controller/Intervalometer Web site:

http://www.bmumford.com/photo/camctlr.html

Winters, L.M. (1990 May). High-speed flash photography with sound triggers.

The Journal of the Acoustical

Society of America

,

87

, Retrieved August 7, 2008, from

http://scitation.aip.org