What's in the hotshoe? If you use a Pocket Wizard or a speed light (in commander mode) or something similar, the pop up should not open.

I have use Canon. In order to use the built in transmitter for OCF my pop up flash must fire to send signals. Is this what you are taking about? If it is I just power down my pop up flash. Not sure how Nikon works.

You can also use the pop up flash in commander mode without firing if you are using it to trigger your remote flash. Check your instruction manual.

Thankyou for your comments guy's, I will delve into my instruction manual. it seems that the pop up flash on my d700 needs to be on wether I'm firing flash from my hotshoe or firing flash in commander mode for off camera flash, otherwise the flash won't fire from my sb600 flash gun. Manual here I come...............

David67, page 309-ish in your D700 manual has the custom setting you need to change to engage Commander Mode.

When you change the pop-up flash to Commander mode, the pre-flash will not normally affect your lighting unless you are too close (subject is around 2-3 feet). If you are too close, it will have a slight effect.

Crazy Glue ( LOL)

Thanks Steve,
I read the manual and even though I have now disabled my built in flash and only have group A programmed for my off camera flash, the pop up flash on my camera still fires???? but like you said Steve, as long as I'm not shooting too close to my subjects it should'nt become a problem.

David67, you need to set the pop-up flash as Commander with flash output of "--" (that is two dashes). The flash output of "--" means pre-flash only, no actual flash.

In Commander mode, the pop-up flash will fire a pre-flash to trigger the remote flash. This pre-flash is visible light. The pre-flash fires right before your remote flash fires, so it gives the appearance of a single pulse of flash (when there are actually two: the pre-flash and the actual flash).

If your pop-up Commander flash is far enough from the subject, its light will have no effect on the exposure. It's only when you get really close does it have a slight effect. In your case, it does not look like you need to that close to your subject.

Thanks for all your help steve, that's a lot clearer now, i programmed my camera settings exactly as you said and the pop up still fires, but if that is just a pre flash that fires regardless then happy day's.
thanks again.

David67, that should do it for you. One last thing: your SB-600 must be within visible sight of your pop-up flash, because the pop-up pre-flash is visible light. Basically, if you stand by your SB-600 and can't see where your camera will be located, then the SB-600 will probably not see the pre-flash from your pop-up.

Also, if you get a SB-700, SB-800, SB-900, or SB-910 as your commander flash, those devices also fire pre-flashes, so you will see the light from them as well. The only way to obtain true wireless triggering is by buying PocketWizard, RadioPopper, Phottix, or any other brand that does not use light or infrared.

Hi David, further to the advice you've received, I recently saw an interesting online article at Nikon Europe which acknowledged that some pre flash may be visible in your photographs when in Commander Mode, and they suggested the use of the Nikon SG-3IR which attaches to the camera flash shoe and covers the camera’s built-in flash to prevent it from influencing the exposure. It apparently blocks all visible light but allows the infra red instructions to be transmitted. It costs about $12 (B&H http://www.bhphotovideo.com/c/product/410445-REG/Nikon_4905_SG_3IR_IR_Panel_for.html ) - I've ordered one but have not yet received it so can't offer any hands on feedback on its functionality, but I'm optimistic, given it is a Nikon product. Here's the article link: https://nikoneurope-en.custhelp.com/app/answers/detail/a_id/11026/~/how-to-use-the-built-in-flash-'commander-mode'

The above mentioned product will probably solve your problem, but when I had the same problem with a 60D and a close-in subject, I just put a bit of tin-foil or other opaque material between the pop-up and the subject. The pop-up flash doesn't need to be as strong as it is in order to trigger the remote, and the foil diffuses it greatly by spreading the pop-up's light everywhere but straight ahead. So, in enclosed spaces the bounced light from the pop-up flash is sufficient to trigger the remote. That's been my experience anyway.

Thanks again stephen, all of your advice has been greatly received and funnily enough SteveH I was thinking that there must be something on the market to block the pre flash from the pop up and if not Mgarber I was going to make something to fit over the pop up to diffuse the pre flash behind the camera. Let me know how the SG-3IR works out for you SteveH.
Cheers guys.

Hi David, I received my SG-3IR and have given it a test run. It fits snugly in the hotshoe of the D700. The small arm rises over the top of the pop up flash, and the square panel which blocks the cameras flash swings down immediately in front of it. It appeared to do as it was supposed to - blocked the cameras pre flash emissions from the subject, but did not interfere with communication with the off camera flash. I experienced no misfires. Whilst not exhaustive testing (!), for the low cost I recommend it as worth a try!

Excellent, thanks Steve, I'll go for it I think.

It is worth noting - as I don't think it was mentioned - that as well as having zero to minor effect on your subject when fired, the commander flash burst will show up in reflective surfaces. Take a picture into a mirror and see what happens. The flash burst will turn up in your image whether the TTL was set to -- or not.

Take a step back from your subject, use a higher F number (the burst really is that weak) and the commander flash will become a none issue.

The little gadget for mounting on the hot shoe (SG-3IR) to block the flash burst can be hard to find - even if you have bought one - so oldsters can make their own, by simply taping a small piece of exposed film over the on-camera flash commander. As all good school boys know; the signal is IR.

Thanks Jack, I'll try that.