Camera Flash Pop Sound: What Causes It?

AI Thread Summary
The popping sound from an external camera flash is primarily caused by mechanical vibrations during the charging and discharging of circuit elements. This includes high-pitched noises from magnetostriction in the inductor of the flash's circuitry. The sound can become louder when the flash is obstructed, suggesting a connection to the energy output. Additionally, parallels are drawn between the flash and thunder, as both phenomena involve supersonic shock waves resulting from rapid thermal expansion. Understanding these mechanisms can enhance knowledge of flash operation and sound production.
CodyW
Messages
3
Reaction score
0
Hi everyone,

I was wondering if anyone knew what causes the popping sound when an external camera flash is fired?

Kind regards
Cody
 
Physics news on Phys.org
An interesting question. I found several possibly answers here: http://forums.anandtech.com/showthread.php?t=2014008

In particular, it seems that the charging/discharging of the circuit elements creates mechanical vibrations which can manifest as pops, whistles, and hums.
 
The whistling / high pitch noise when the camera flash is charging up is caused by magnetostriction on the inductor of the flyback converter in the flashes circuitry. I think possibly the LC resonance may play a part as well. :)

The pop sound when the flash is fired, I've noticed, gets louder as I put my hand up close to the end of the flash. Would it have something to do with the energy coming out of the flash?

Sorry for the poorly written post. I've had close to no sleep haha.
 
I don't know how far of a parallel can be drawn, but reading wiki articles for both flashtubes and thunder, each mention supersonic shock waves related to rapid thermal expansion of plasma produced by the electric arc.

Flashtube: http://en.wikipedia.org/wiki/Flashtube
Thunder: http://en.wikipedia.org/wiki/Thunder

Flashtube:
Flashtubes produce an electrical arc flash contained in a glass tube. As the arc develops a supersonic shock-wave forms, traveling radially from the center of the arc and impacting the inner wall of the tube.

Thunder:
In the 20th century a consensus evolved that thunder must begin with a shock wave in the air due to the sudden thermal expansion of the plasma in the lightning channel.
 

Thread '1:1 versus 2:1 Mechanical Advantage debate'

The rope is tied into the person (the load of 200 pounds) and the rope goes up from the person to a fixed pulley and back down to his hands. He hauls the rope to suspend himself in the air. What is the mechanical advantage of the system? The person will indeed only have to lift half of his body weight (roughly 100 pounds) because he now lessened the load by that same amount. This APPEARS to be a 2:1 because he can hold himself with half the force, but my question is: is that mechanical...
View full post »

Thread 'Newton's first law?'

Some physics textbook writer told me that Newton's first law applies only on bodies that feel no interactions at all. He said that if a body is on rest or moves in constant velocity, there is no external force acting on it. But I have heard another form of the law that says the net force acting on a body must be zero. This means there is interactions involved after all. So which one is correct?
View full post »
Thread 'Beam on an inclined plane'

Thread 'Beam on an inclined plane'

Hello! I have a question regarding a beam on an inclined plane. I was considering a beam resting on two supports attached to an inclined plane. I was almost sure that the lower support must be more loaded. My imagination about this problem is shown in the picture below. Here is how I wrote the condition of equilibrium forces: $$ \begin{cases} F_{g\parallel}=F_{t1}+F_{t2}, \\ F_{g\perp}=F_{r1}+F_{r2} \end{cases}. $$ On the other hand...
View full post »

Similar threads

What Caused the Strange Flash of Light in My Bedroom at 3:57am?
Replies
23
Views
3K
I Unidentified Luminescent Phenomena (ULP)
Replies
1
Views
3K
B What sound frequencies can pass through a hole in a wall?
Replies
31
Views
3K
Why LED Lights Aren't Used in Camera Flashes/Strobes
Replies
3
Views
2K
Velocity, acceleration, jerk, snap, crackle, pop, stop, drop, roll....
Replies
3
Views
3K
What Gauge Wire for Remote Camera Flash?
Replies
5
Views
2K
I Force Required for Gas Struts on 1972 VW T2 Danbury Pop top campervan?
Replies
9
Views
2K
Why Do Modern Digital Cameras Flash Twice?
Replies
18
Views
2K
I Sound pressure and inverse distance law
Replies
5
Views
2K
Using Half of a Dome for Whispering Gallery Effect?
Replies
15
Views
3K

Hot Threads

Recent Insights

Back
Top