On Camera flash. This is a straight 'snapshot' using the Auto setting and the on-camera flash. It is very flat, there are no shadows to give the shot depth and much of the stalctite detail is lost as it is white on white.
There is also not enough light on the people, which could be improved simply by moving them toward the light source.
Side lighting. This shot used a flash fired manually from about 2m right of the camera.
The shadows give the shot much more depth and detail.
The difficulty lies in ensuring the scene is evenly lit - in this case the stalactites in the top right are too close to the flash and over-exposed.
Back lighting. A totally different effect obtained by simply firing the flash directly into the lens from behind the subject.
The shot below was set up exactly the same way, with the only difference being a higher ISO was used, doubling the amount of light in the image.
Multiple Flash shots. The shot below is done with a single flash fired twice manually (once to light the subjects and once to light the foreground). A long exposure (10 to 15 seconds) is used to allow the flash to fully recharge and care must be taken not to get any light from the second flash on the subjects as they can't help moving a little!
The hardest part of these sort of shots is making sure the flash to subject distance is right for each flash.
The shots below both used long exposures and multiple flash units, fired by seperate people. The same flash was used to light the walls of the chamber both times and was positioned in the middle of the chamber and fired four times in different directions.
This is a "first attempt" of a shot of the Main Chamber.
The flash in the foreground has overexposed some of the formation. Simply moving it a couple of meters further away from the formations could fix this.
There is also nothing for reference in the shot to show the size of the place!
The "second attempt" a week later.
The flash used in the middle distance was the same as in the previous shot.
In this shot we positioned the flash in the foreground so as not to over expose the formation and a third flash was fired at the rock in the distance, over-exposing it a little to silhouette the person holding the flash, giving the shot a reference for scale.
Firing the flashes manually is the simplest, very low tech method. You need flash guns with 'test' buttons and enough people to hold them! Just position people where you need them with a flash, use a fairly long exposure, make sure all the lights are out and yell "now" loudly when you want the flashes to go off!
Multiple light sources. These are the hardest shots to get the exposures right. I find the best thing to do is get the exposure correct for the natural light, then balance the light from the other light sources by either varying flash power levels or the flash to subject distance, or the time the LED lights are on.
This shot used a blue LED, a red Led, a flash and natural light. It was shot in RAW to allow the colours to be manipulated in photoshop.
An awesome result from a long exposure to capture the natural light and back lighting the waterfall by panning an LED headlamp up and down it. Fortuneately the LED had a greenish tint which blended with the green natural light from tne entrance around the corner.
This shot uses natural light and three flashes. Two were fired manually and the third by optical slave.
