With the Slow Sync and Rear-Curtain Sync functions of the N90s work with an SB20? If not...how about the SB24? I am looking at buying a used flash this weekend but I don't want to spend a lot of money. 95% of my photos are taken out doors in bright daylight. Side Note: My lenses are not the "D" type so 3D Flash is not a concern. Thanks in Advance, Eric
