Edit : This is only applicable to the D40 , D50 and D70/S since they use an electronic shutter for higher speeds rather than a focal plane shutter as other camertas do . Update : see my realsncyh blog A few people have expressed interest in high speed flash synch so I thought I'd take a few pictures of my newly acquired SB24 being 'converted' . [edit: you can do this with any of the older Nikon flashes that have "A" mode - or just use a flash with one pin ] The 'easy' method is to slide a piece of paper under the back two pins to disconnect them from the camera . NOTE : this only works with the D70 , D40 and D50 [ and maybe the D100 ] since they have a mechanical shutter plus an electronically switched shutter that allows flash synch at any speed limited only by the firing time of the flash . Here's a picture of the bottom of the flash and the associated pins .... the two bottom pins are the ones to disconnect , one of them tells the camera there is a flash connected and ready to fire - we don't want that because then the camera defaults to flash speeds , maybe 1/60th to a max of 1/500th [ the new D90 can only do up to 1/200th !] . The other pin is useless because the SB24 doesn't speak the same language as i-ttl on the newer cameras . The top pin could also be disconnected but comes in useful if you have the flash set to 'standby ' mode because this pin tells the flash when the camera has been turned on and wakes the flash up !