#2. "RE: D-4 TTL Flash at High ISO" In response to Reply # 0
Richmond Hill, GA (Savannah), US
The reason the SB800 tops out at ISO 1000 is that the lowest power it can fire at will not be low enough for really close shots at ISO's above 1000. However, for shots at a few feet or more the SB800 will work fine up to ISO 2500 or so. For ISO 12,800 or higher, you will have to be considerably farther away from you subject to avoid overexposure.