Not reef related but had to share!!!

[sphelps]

Originally Posted by Delphinus

Sorry but can you elaborate a little? I'm having trouble wrapping my brain around the "double the inverse zoom" part.

Shutter speed is displayed as a fraction of a second, for example 1/250 of a second. Zoom is in mm, so if you're shooting at 200mm then you should aim for a minimum of 1/400 shutter speed. I maybe should have said double the zoom then inverse. Its just a rule of thumb and of course there are exceptions.