I shot a wedding a few weeks ago, using on-camera bounce flash, and I really struggled with too slow shutter speeds. I was on Aperture Priority, as usual, and I was trying to use fast apertures for shallow depth of field. I kept getting 1/15th, even though my aperture was 2.8 and my ISO was 800 – this is with flash helping out! I was shooting for my friend Jack, who has the same camera but a slower 18-200mm lens. He was getting 1/60th, f/5.6 at ISO 200!
I’ve tried everything I can think of. Active D lighting on? No. Minimum flash sync speed (setting f2 in the D300) too low? Well, yes, it was, but that didn’t solve the problem. Lens aperture sticking closed? No. Matrix metering – check. Auto ISO? Off. Auto ISO on and set to 1/60th minimum shutter speed? No effect.
I had just about given up. Actually, I gave up.
I was just testing using the SB-800 as my master (instead of the pop-up) and noticed that I was still having that problem. I fiddled around with settings here and there, and suddenly, it was fixed!
USING REAR CURTAIN SYNC ALLOWS SHUTTER SPEEDS SLOWER THAN THE “f2” SETTING SPECIFIES IS THE MINIMUM SHUTTER SPEED!
By turning off Rear Curtain Sync, my shutter speed would no longer dip below the “f2” setting I specified.