Here is a simple study on the effects of shutter speed when doing long exposures. As I waited for the projection and firework shows, I photographed Cinderella Castle in the Magic Kingdom using longer and longer shutter speeds.
Each photo was taken with a Nikon D750 full-frame digital SLR camera using a Nikon 24-120mm lens locked down on a tripod. I used these camera and lens settings for each exposure: Focal length at 50mm, Aperture at f/16 and ISO at 100.
Shutter speed: 5 seconds.
Cinderella Castle at dusk with a 5 second exposure.
Shutter speed: 13 seconds.
Cinderella Castle at dusk with a 13 second exposure.
Shutter speed: 20 seconds.
Cinderella Castle at dusk with a 20 second exposure.
Shutter speed: 30 seconds.
Cinderella Castle at dusk with a 30 second exposure.
The only other variable was time. As you can see Blue Hour had not started with the first photo but it was very evident by the third one. Blue Hour had disappeared by the last one. What else can you see changing as the exposures got longer?
Scott; The people ‘blur’ is greater with the longer exposure. I’m not sure if it’s due to the changing light but the last picture seems to have more what I call hazing around the street lights. The is also more detail in the lower part of the castle with the longer exposure.
Scott replies: right on all counts, Steve!