There may be a very simple solution to this, but when using the on-board flash I get a black fall-out at the bottom center of my pictures. It appears that the lens is creating the shadow. I have the Nikkor 18-200mm lens on the camera. I've tried every shutter speed, etc., but it doesn't seem to make a difference, so I assume this is the cause? Is there no way to avoid it, except use my SB600 flash mounted instead? Using this I have no issues.
Yup, it's a function of the physical length of the lens, the wide FOV, and the proximity of the on-board flash. You have more control and setting options if you use your SB-600, and you won't have the same problem with the lens getting in the way.
Light does not necessarily travel in a straight line. If light travels near a massive object such as a black hole or big star then the apparent path of the light will appear to be curved. If the object has enough gravitational force then the light can be completely trapped and will not be able to escape. This is what occurs in a BLACK hole.
But for most practical and terrestrial purposes, you're right. Light travels in straight lines.
Imagine what kinds of lenses could be produced using gravity waves to bend light... (food for thought)
>Light does not necessarily travel in a straight line. If >light travels near a massive object such as a black hole or >big star then the apparent path of the light will appear to >be curved.
I thought of that when I wrote 'light travels in straight lines'. I know that light is deflected by strong gravitational field but concluded that if you were sufficiently near such a field for it to have an effect, you wouldn't be worrying about black bits in your photos anyway...
Besides, since light also slows down as it approaches the event horizon, you'd get underexposure and need to dial in +EV, unless of course you've set Custom function K96 to 'Black Hole'...