Originally posted by jrforman My understanding is that Slow speed sync is there to allow you use a lower shutter speed to allow more ambient when you are using a flash. In TV mode, you are selecting your shutter speed just like in TAV and Manual. Since you select it, it doesn't seem like it would be an option. It would be applicable in Av, Sv and P mode.
Similar to what jrforman said, the K-5 manual suggests that when using Slow speed sync in Tv, TAv, or M mode, the word 'SLOW' will not appear next to the flash icons on the [FLASH MODE] screen. I believe this is because
you are selecting the shutter speed in these modes, which causes it to be slow-sync. I just tried it on my K-5 w/ FW 1.03 and 540 flash. However, I get better exposures using the Av mode with a SLOW flash icon selected in the [FLASH MODE] screen.