Ideally, a hydrogen fuel-cell vehicle has no environmental impact. Energy is produced by combining hydrogen with oxygen pulled from the atmosphere, and the tailpipe emission is water. The hydrogen fuel could come from a number of sources (Iceland recently started pulling it out of the ground).
4) Fast, Slow and Long Shutter Speeds. Fast shutter speed is typically whatever it takes to freeze action. For me, it is typically above 1/500th of a second for general photography and above 1/1000th of a second for bird photography. NIKON D700 @ 420mm, ISO 450, 1/2000, f/5.6.
2. High-speed sync flash is used when you want to use a shutter speed that is faster than your cameraâs native flash sync speed, or when you want to use a wider aperture setting that requires a higher shutter speed as is often the case with outdoor daylight shooting.he flash instantaneously lights up the subject (it does travel at the speed of light), so the flash doesn't last nearly as long as the shutter remains open even though this is very fast (1/60s, 1/125s 1/250s, etc.). There is a limit to the shutter speed, and this is the cameraâs native sync.