Sorry this may be a rather elementary question, but my understanding of flash is rather elementary also. The last line of a paragraph in my SB-28 manual reads " This system does not directly link the camera's light meter and the SB-28's TTL sensor." What exaclty does this mean?
"It's like you can see s***, but you have no idea what it looks like." -Mark
I think what the manual is trying to say is than in TTL mode, the SB-28/camera combination does not take the ambient light into consideration. The TTL sensors, which are in the camera and not on the SB-28 itself, control the flash duration. This results in the main subject being properly exposed while the background may be (and usually is) underexposed.
This is in contrast to Matrix or Multi-Sensor Balanced Fill Flash, where the camera takes the ambient light into consideration and tries to have proper exposure for both the main subject and the background.
The confusion arises when the manual refers to the "SB-28 TTL sensor". That sensor does not exist. This is probably a translation error from the Japanese.