Fri 10-Aug-12 04:40 AM | edited Fri 10-Aug-12 07:58 AM by GJW_2012
My goal is simple but causing me problems: I want to fire my external SB-700 and capture my image *without* the built in flash firing in the picture. The problem, especially with portraits, is that when the built-in flash fires to trigger the SB-700 it creates a lot of unwanted light and additional catch lights in the subject's eyes.
Please excuse me if I'm missing something obvious. I've tried adjusting all the 'Flash control for built-in flash' settings (e3 on D7K) using built-in flash mode '--' and Group A 'TTL'. The testing that I did caused more confusion as I got inconsistent results - sometimes the built in flash would fire in the picture and sometimes it would not - all with the same image composition, ambient lighting and camera/flash settings etc.
I don't want to spend another few hundred on pocket wizards as I've seen this work on other Nikon systems and I've now witnessed it on my own system.
Welcome to Nikonians! Even with the built in Speedlight set to -- it will fire a triggering flash at very low power when the shutter opens in order to fire the remote Speedlight(s). With the Speedlight set to -- the built in Speedlight will only contribute to the exposure at macro distances or very close to the subject. You can get a Nikon SG-3IR and mount it in the cameras hotshoe to convert the white light from the built in Speedlight ti Infrared light that will not contribute to the image but will still control the remote Speedlights. Good Luck and Enjoy your Nikons!
In it, one of the guys and I work through some experiments to show that the onboard flash, even in "--" mode, does, in fact, make a contribution to the exposure that cannot always be considered insignificant...even at distances greater than macro and PARTICULARLY when you are using large apertures and/or very sensitive ISO settings. Ultimately, the other guy works through enough experiments to determine the guide number of the on-board flash in "--" mode.
Ultimately - the SG3-IR, as Marty recommends, is your best bet. I've used it for several years for precisely this purpose. The only thing to look out for wiht this device is that if you are shooting into reflective surfaces like glass, using this device can cause a very minor, reddish speculative highlight in your shot. I was shooting a beer glass once using lights reflecting off a white background behind the glass and triggerd by the popup w/ SG3-IR. When I peeped in close, I could see a hint of the Red light reflected in the glass that results from the light passing through the IR filter. Just FYI.
Thanks guys for your help, sounds like the SG3-IR is the way forward. Altho I do recall reading somewhere (cannot find where!) that infrared light is terrible for the skin, brings out veins and blemishes etc. I'm guessing there won't be enough IR light to make this an issue altho makes me paranoid enough to test this thoroghly. SG3 is on the way, looking forward to testing this out. Really appreciate your help!
Mon 13-Aug-12 01:06 AM | edited Mon 13-Aug-12 01:12 AM by gkaiseril
That is true if you are only using IR as the only light source. All of the pre-flashes occur with while the shutter is closed and thus no exposure. The only flash from the Commander device is the trigger signal at less than 1/128th of the full power of the flash so if the remote fires at full power there is only a small amount of IR that might be captured. Most people will not even see it except for very dark and very closeup shoots the bare commander white light is not very visible.
It is even possible in a small space to put a white card a few inches infront of the pop-up flash to block the light falling on the subject but let reflections from the walls and ceiling trigger the remote flash.
You could even use another SB-700 in the commander with the head turned 180 degrees fro the lens to trigger the remote and have very large reflector created by the wall behind you.
All of the advice you have received is good. One other thing to consider, if you aren't sold on or happy with the SG-3IR, is an SU-800 Commander. It gives you some added flexibility over the built-in commander mode in the camera or the commander mode of a SB-700. About $250 street price.
I don't know if his helps or if it would hinder the off camera control of the flash but I have used a white tissue, Kleenex, over my camera flash with good results. Cheap fix if it works for you. I suppose it is kind of like a soft box?