I just started using a Nikon SB600 and have been blown away with the results.
This is my first TTL flash unit. In the past I shot film used a Q-flash and Vivatar 283/285's with radio slaves.
I keep reading about using the SB800 to control an SB600.

So...
1) Is this an optical slave? In other words if I am shooting where other people are shooting behind me, like a wedding (curse them) using an SB800 on camera will their flashes set off my (slave) SB600. I ran into that problem using optical slaves before I got radio slaves.

2) What fires the SB600 as a slave. Mine has a little window on the right side (viewed from the back) which I assume is the sensor. What if I place it to the right of me, or if I use two SB600's, one to the right and one to the left. I have used this before with LARGE (maybe 40 people stacked 3 or 4 deep) family groups with good results in a church. Will the slave still fire if the window is not facing the master (SB800)?

Given your hardware, the best way (ie: least expensive for you now) to control your SB-600 off camera is using Nikon's CLS (Creative Lighting System). Your camera (thru its pop-up flash) can be configured as the Commander while the SB-600 would be configured as the Remote (not a "slave"... a slave is in essence a "dumb" flash, while the SB-600 configured as a Remote in the CLS is really pretty smart... especially in i-TTL mode). Info on the CLS is in your camera and flash manuals.

The CLS is capable of working in full i-TTL mode (among some of its other abilities). The CLS is controlled thru IR signals... it is not an optical slave based system. So the probability is very high that other cameras will not fire your flash(es) when you use the CLS (I've never had a problem with other cameras firing my flashes when I'm working with the CLS). You should experiment with the CLS to see if its abilities to control off-camera remotes suits your needs. It is a very capable system, offering good range in many different shooting environments.

Some additional on-line resources are:

http://www.nikoncls.com/SB-600/sb600_review.html

http://nikonclspracticalguide.blogspot.com/2008/01/nikon-flash-two-separate-metering.html

This link is for the SB-800 but there is alot of useful (and relevant) info that SB-600 owners could find useful. http://www.juliagreerphotography.com/sb-800-article.htm

There are alot more on-line resources to assist you in enjoying Nikon's CLS. It's a nifty system.

Hope this helps,

Greg

The remote flash can be aimed at the master and the head can be aimed where you need it. That way it (the base part) is more likely to see the control signals which are near-infrared light signals. It can be triggered by other people's flash units if they are set for master/slave operation but the best chance of avoiding that is to use a non-default channel for your units.

Slave units will operate if they see the control signal whether that be directly or reflected off something like a wall or ceiling. The more direct the link the greater the separation can be without a communication error. Also, the less ambient light there is the greater the separation can be.

You can control the lighting ratio between flash groups but unless you use the most recent SB-900 as a master you will get at least some flash from the master in your image. That may give you slight but unwanted specular highlights.

- Alan

Thanks all for the info...

Yes, the sb-600 can be fired by other Nikons, but only if they intentionally set up their camera to do so. There are only 3 channels to use so it would only take a moment to determine which channel you're using.

Last night, I set up a photo booth strobing an sb-600 & sb-800. I was triggering them with my d300 and my friend could also trigger them with his d200 simultaneously.