Fujifilm X-T1 users that have old Nikon flashes, take note. You can use Auto Flash Mode for quick pics. The Angry Photographer over on YouTube mentioned this in a video, so I thought I would expand and share.
If you have a Nikon flash capable of Auto Mode, all the way back to the SB-24's, 28's and more, they should work. I think SB-600's won't and maybe a few others, sorry. I've only personally tested my SB-910, and none of the others. I'm not sure if this will work with other brands. It basically let's the flash figure out what the exposure is.
The way auto mode works and the way we used to do things, back in the day, before TTL, was use Auto Mode and I've forgotten about it, is the flash will fire, the light bounces back and hits a sensor on the front of the flash and it shuts it off when it thinks it is exposed correctly. It actually works quite well. You're camera just needs to fire the flash, either on the hot shoe, cable or a remote dumb trigger. If experimenting, just be careful of really old 3rd party flashes. Make sure the sync voltage won't burn out your camera. They used to be quite high. I wouldn't put my Vivitar 285HV on the show, for fear of that very thing. It may be fine, but I won't take a chance.
Basically, if you put the flash on Auto Mode, set the ISO and the f-stop to match the camera. Zoom can be set also, but I just keep it near where I'm shooting. Note the distance scale and keep within that measurement. I've found that you don't have to be 100% accurate with the f-stop, however closer the better. You can adjust with the compensation also on the flash if needed. I find it is pretty darn accurate.
From there, all you have to do is trigger the flash. It can be on the camera, cable or a trigger. Of course, you want to shoot Manual or Aperture priority to keep the camera aperture from changing on you. Just as in shooting manual, the distance scale is flash to subject. It doesn't matter where the camera is. It even seems to handle bounce fairly well.
There's a lot more tech stuff that can be talked about, but I'm trying to keep this simple. Experiment and let me know how it goes. Of course, if you have the time to set up, Manual Mode rules!
BTW, an X-T1 looks pretty funny with an SB-910 sitting on top of it!
UPDATE: It was verified to work by someone on my G+ with an SB-28, SB-80DX and an SB-800. The SB-600 will NOT work. It doesn't have an Auto Mode.