adz929 wrote:I wouldn't say the inbuilt flash is completely useless. There have been many times when I have used it for a quick bit of fill flash and it also makes for a handy master flash too. The SB-400 is a nice little compact flash that will give you a little extra kick. The SB-600 puts out more power, can act as a slave and will give you a decent AF assist beam. The SB-800 puts out even more power, can act as a slave and a master, allows you to plug in additional batteries for faster refresh times and gives you an AF assist beam. The SB-800 has a few other features however, I doubt they are of much use. Personally, I always carry a pair of SB-600's with me, I just couldn't justify the extra cost of the SB-800.
The sb800 allows me to attach a Pocket Wizard to the flash and place virtually anywhere I want when shooting models. You don't have that latitude with the sb600.
In the photo below, I was able to place a sb800 (connected to a Pocket Wizard), in the middle of the street between the model and I. In several shots of this series, I was actually shooting the model from the opposite side of the street, and using the sb800 (in the middle of the road) for fill. I highly recommend the SB800.
http://www.pbase.com/teiladay/image/88826567Teila K. Day