I just bought a SB28 and a SU-4 and would like to have the built in flash of the N80 activate the SB28. First time out it didnt work well at all. All the pictures were badly over-exposed. I had the SB28 to the side and a bit forward of the N80(which was on a tripod) trying to get some great family pictures (with me in them too, shot in timer mode). The strange thing is I spot metered someones face and still the TTL did not work well at all. The *beep* from the SU-4 only went off once which I beleive indicated that it did not fire at full power, so why was everyone so badly blown out? I also used the SB28 on-camera and those shots turned out correctly exposed (but had the shadows that I wanted to avoid by getting the flash off-camera) I had the SB28 set to TTL, was shooting Fuji Superia 400 with a 50mm 1.8f lens at 1/60 and 1/90sec, cannot remember the fStop Please help.
#1. "RE: Need help with SB28 and SU-4" In response to Reply # 0
silly-can valley, US
It's me again , this time trying to read carefully.
there happen to have a post related, scroll down and see the thread: "Help! Problem with slaved SB-28". I think the answer was decent.
I do not know how you sb28 "a bit forward of the N80" as your N80 preflash and calculate flash output based on camera-to -subject distance, not flash-to-subject distance, if you place sb28 to the side, could you use the same radius as your camera, or try to use flash compensation (set this on camera) if you prefer moving sb28 nearer.
Here is an another topic but related:
I do not know what is our final goal to use multi-flash here. if your purpose is to making flash even and leaving no shadow, you can use single flash (use your sb28) get a flash braket ($40 - $150), put sb28 and your camera on the bracket, and connect via a sc-17, in this case sb28 is not a slave but a TTL flash unit. The result is pretty decent, need less calculation and quick to set up.
Personally if I use multi-flash (2 specifically), I typical put the slave one totally side (90 angle or 180 with master), instead if use the slave as another front (although may be sided somewhat) light (bouncing is an exception), as I found the effect using bracket is much better.
#2. "RE: Need help with SB28 and SU-4" In response to Reply # 1
Thank you for your response. Yes I was trying to reduce the shadows and not get a deer in the headlights look.
I will try to find that previous thread you mentioned.
It should not matter what the slave's distance is since it should be using TTL (I thought) and I shot in Spot meter mode which means that there was NO monitor pre-flash. Unless I misunderstood, using the SU-4 the SB-28 should be still TTL. The Flash was to on side (at about a 45 degree) and only about 1-2 feet closer (as the directions on the SU-4 say to place it infront of your main light so its' sensor will pick up your primary flash)
with the ISO 400, may be the shortest flash duration the camera can manipulate on the built-in one already exceed what is desired duration. I vaguely remember N80 with flash, the iso can be only up to 800 (i have no manual handy), that is said with built-in flash in mind, with you adding one more (much larger GN) speedlight and with closer distance (which translate to even larger GN), the effective upperbound ISO film in flashing using built-in speedlight really dwindled. I'll try smaller aperture or, say, using ISO 100 (as Fuji Reala is pretty good used for flashing).
Here is the excerpt from the website mentioned above, related, credit to Guy Parsons:
For AUTO mode the master flash can be any brand flash on any brand camera that is TTL controlled. The slave just adds to the general flash illumination and the camera will sense the total light and turn off its flash when enough is received. This main flash turn-off is sensed by the SU-4 and it turns off its slave flash. If not enough illumination was sensed so that the slave unit does not get a turn-off signal before the slave flash capacitor is completely emptied, then the usual Nikon flash underexposure warning noises occur plus the SU-4 will beep for three seconds (if switched to beep mode). If too much light was received then there is no indication of overexposure. Maybe the extremely short flash timing may be a clue, but experience will have to teach you how to set it up properly.