The built-in flash on your DSLR camera has many limitations such as short effective flash range, fixed coverage, etc. It may also be limited by the lens you use and the type of photography you want to do. One problem is that the light coming out of the flash may be blocked by the lens (or lens hood) when shooting subject at close range. That’s exactly what happened to a flickr user:
I’m having this problem of having shadows on my pictures whenever I take shots which is close-up and having less light. So I go with my built-in flash on my Nikon D90. I always use my hood lens for protection but I’m having these shadows bellow my pictures. What should I do? Should I change my hood lens or just remove it when there is less light? I’m using a 18-200mm lens and the hood lens that comes with it is pretty big. Please help. I need some tips.
Many others responded with suggestions to take off the lens hood (will help to a certain extend) or get an external flash. Indeed, an external flash such as Nikon SpeedLight SB-400, SB-600, SB-800, SB-900, and the macro photography centric R1C1, are great light sources for creative photography especially when used off-camera. It would be very easy to avoid the lens or lens hood shadow.
If for any reason you don’t want to get an external flash yet, you could certainly try the DIY approach. One example is this built-in flash extender and diffuser. All it takes are a plastic bottle, a piece of tape, a rubber-band and some aluminum foil. More pictures of the setup can be found here.
One of the more complicated examples is the DIY ring flash for built-in flash (Shown below).
If you don’t feel like spending your time to save money, you could try some commercially available options. This £8.50 ($12.39) diffuser appear to be able to help with the lens (hood) shadow problem (shown below).
Keywords: diffuser, DIY, Do-it-yourself, Extender, Flash photography, Light Modifier, Photography DIY