A Mystery
Dec 31, 2015 10:52:59 #
While taking photos of night lights at the "Luminaria" presented at the Desert Botanical Gardens in Phoenix, I mistakenly had set my shutter speed at about 3 seconds. The results are interesting to view.
The first two photos have LED lights which were captured in multiple images, while the red incandescent lights were just streaks.
What is happening here? My scientific daughter tells me that LED's do not glow continuously, but do turn on and off as they charge and discharge light. Of course the old incandescent light burn continuously.
Now observe the last photo. Why are the musicians captured on the sensor, while the lights and moving across the screen? I think I have an idea what caused this, but I would invite any comments from my fellow Hoggers.
The first two photos have LED lights which were captured in multiple images, while the red incandescent lights were just streaks.
What is happening here? My scientific daughter tells me that LED's do not glow continuously, but do turn on and off as they charge and discharge light. Of course the old incandescent light burn continuously.
Now observe the last photo. Why are the musicians captured on the sensor, while the lights and moving across the screen? I think I have an idea what caused this, but I would invite any comments from my fellow Hoggers.
Dec 31, 2015 10:57:24 #
Dec 31, 2015 11:26:13 #
It appears that the LED lights go on and off at 60 cycles per second due to the alternating current. Incandescent filimants don't respond that fast. Neither would glowing gas.
I'd guess someone took a flash image of the musicians while your shutter was open.
I'd guess someone took a flash image of the musicians while your shutter was open.
Dec 31, 2015 11:51:26 #
Kingmapix wrote:
While taking photos of night lights at the "L... (show quote)
The musicians were captured (albeit blurry) because your camera moved considerably at first and then became pretty still for a short period of time allowing them to be relatively clear. You can easily see this motion-stop movement in the streaks of interior light that come in at the top of the image and then become a more stable blob at the bottom of the streaks.
The longer streaks in the foreground may be reflections in the window glass (?) you shot through and the distance from the light source to the camera sensor was greater causing the "blob" at the bottom of the streak to more clearly reflect the actual motion of the camera. Whether they are reflection or just closer lights it is the distance to the sensor that causes the different tracks.
An interior flash is not the cause as that would have literally frozen the interior action, and the shadows on the backdrop also indicate the prevailing light was from above (referring to the shadow of the high top propane heater).
Jan 1, 2016 08:40:40 #
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