Woah, alot of information there, I unfortunately do not have a remote shutter release. My sb600 will need a cord to be used as an off camera flash which unfortunately I also so not have. If you are familiar with the SB600 how would i set it to syc on the rear shutter curtain? Is that in the manual ?
Yes as you can see fromt he above comment, I AM NOOB! when it comes to the technical aspect of it.
The SB-600 doesn't have a port for a cord.
Rear curtain sync is set in the camera.
Using flash introduces a level of complexity to doing photography. It takes a good basic understanding of how the camera functions.
A dSLR camera shutter has 2 curtains. Nikon calls then the front and rear curtain, Canon calls then the first and second curtain.
At any rate, when you trip the shutter the front curtain drops exposing the image sensor. When the time the shutter is set to is up the rear curtain drops covering the shutter and stopping the exposure.
At that point both curtains reset to the top of the shutter, ready for the next exposure.
When doing flash photography it can be advantagous to have the flash fire as soon as the front curtain has exposed the image sensor, or at the beginning of the exposure. At other times it is advantagous to have the flash trigger just before the rear curtrain starts to close, or at the end of the exposure.
In the case of front curtain sync and a moving subject you can get a bright sharp rendering of a moving subject from the short duration of the flash, and then as the subject continues moving you get a dimmer ghost in front of the subject that is recorded by ambient light.
With rear curtain the ghost is behind the subject because the dimmer ambient lit motion occurs before the brighter flash that happens at the end of the exposure.
Most cameras have an x-sync speed, which is the fastest shutter speed wher the front curtain opens fully before the rear custain starts to close, usually 1/200 of a second or so. Your D40x has a 1/200 sync speed and no capability to do FP-sync which allows using shutter speeds faster than 1/200 when using flash. The duration of the flash an SB-600 has is about 1/1000 at full power and as short as 1/40,000 at it's lowest poer setting.
At faster shutter speeds the front curtain has not fully opened before the rear curtain starts to close. The gap between the two curtains is a slit narrower than the image sensor is high and a flash has to fire
several times during the exposure as the slit exposes different parts of the sensor, (FP-sync mode)
Check out this link and watch how a shutter works:
Jeffrey Friedl's Blog Nikon D3 Shutter Release in Super Slow Motion