Nikon makes several Speedlight units that work very well with the Nikon D300(S). I personally have used the SB-400, SB-600, SB-800, and SB-900 units with the D300(S). There are also the R1C1 flash units (SB-R200), which are designed to be used in small groups, such as for a ring-light arrangement.
Figure 12-13. SB-900 Speedlight
I really enjoy using the Nikon SB-900 Speedlight unit (see Figure 12-13). It is very powerful and easy to use in the CLS arrangement because it has external controls for setting remote mode. It can also be used as a CLS commander when needed.
Figure 12-14. SB-800 Speedlight
The SB-800 ...