Newb Flash Question
/forum/topic/1166113/0



gabrielgartner
Registered: May 05, 2010
Total Posts: 45
Country: United States

Hi All,

I have a flash question I was hoping you all could help me out with. I am experimenting with using my sb600 as a slave with my nikon d300s. When the flash is on camera and I want to use it as fill, I use either A or S mode with shutter speed set at a minimum of 1/60 (unless there's more light) and shoot away dialing compensation as needed on the flash. If I want the flash to be the primary light source, I set the camera to M and the max sync speed for the d300s which is 1/250 and again shoot away.

Now here's my question--with the flash off camera as a slave, does anything differ whether I want to use the flash as fill or as the primary lighting source? I know for flash compensation I have to dial it in on the camera rather than the flash (when the flash is off camera) but other than that is there a difference? In other words, with the flash off camera as a slave, do I still put it in A or S to use as fill and M to use it as the primary source?

One final question--is it possible using the set-up I explained (one sb-600 off camera and a d300s) to use the on camera flash as my primary light source and the off camera flash as fill (can I control the power of both flashes individually)? I cannot figure out how to do this in the custom settings for the life of me. The only thing I can think of is to set both flashes to TTL and set the camera to M and then dial back the exposure on the slave.

Any thoughts? Thanks!

Gabriel



sic0048
Registered: Oct 19, 2011
Total Posts: 247
Country: United States

First - the D300s built in flash is a CLS (Nikon's Creative Lighting System) master commander module which means you can control the off camera flash via the in-camera flash. This will also allow you to use the in-camera flash as a light source too (could be main or fill or whatever you want).

I googled and found this youtube video which may help explain the technical aspects. It is showing a D300, but I suspect the menu system is very similar to the D300s.
http://www.youtube.com/watch?v=QRFNbZ8P3LY

Second - I just want to make sure you understand what shutter speed and aperture and ISO do to your flash. Your shutter speed will have zero effect on your flash power until you go above the max flash sync speed. This means that shooting something with the flash at 1/60th a second vs 1/250th a second will not change the flash effect on the image. What the shutter speed DOES effect is the ambient light. So shooting something with flash at 1/60th a second will allow more ambient light into the image than shooting at 1/250th will. You must have a basic idea of this since you are shooting at a slower shutter speed when you want to use the flash as a fill light and closing the shutter down when you want to use the flash as the primary source. However you don't need to always shoot at 1/250th to use the flash as the primary light source. Be willing to experiment with the shutter speed and you may find your images look a lot better because you can get a good mix of flash and ambient irregardless of which one you are using as the main and fill source.

On the other hand, aperture and ISO will effect both the ambient exposure and the flash exposure. So changing these settings will effect both. Of course if you are using the flash in TTL mode, the flash will automatically compensate for the change in flash exposure and the end result will be no noticeable difference in flash exposure. But if you use your flash in manual mode, then changing ISO or aperture will result in a noticeable change in the flash exposure.



gabrielgartner
Registered: May 05, 2010
Total Posts: 45
Country: United States

Cool, thanks.

I've been playing around with it a bit and quickly realized how to use the shutter speed to effect ambient. Aperture and ISO are a bit tricker for me thus far. I'm still using the flash in TTL mode so it's not a huge issue yet.

I suppose a better way to phrase my original question is if I don't turn the on camera flash off (I use it in TTL mode as well). How can I adjust the on camera flash as well as the slave? Once in commander mode, altering the flash compensation on camera adjusts the slave correct? What if I want to dial in compensation on both the on camera and slave?



BrianO
Registered: Aug 21, 2008
Total Posts: 8526
Country: United States

gabrielgartner wrote: ...Once in commander mode, altering the flash compensation on camera adjusts the slave correct? What if I want to dial in compensation on both the on camera and slave?

I'm a Canonite, not a Nikonian, but if Nikon's CLS works like Canon's Wireless Flash, Flash Exposure Compensation will affect all flashes in the system, and to change them individually you change the flash ratios.

Exactly how to change ratios on your camera is a Nikon-specific question that I can't answer.