Black Background

The second exercise in the Lighting 102 course at http://www.strobist.blogspot.com/ is concerned with the ratio of flash to subject distance and flash to background distance. Control of this ratio allows the relative darkness of the background to be fully controlled. All of these images were shot at ISO200 with a shutter speed of 1/200th second. The subject is 1.5m from the background and the flash is at approximately 45 degrees to the right. The starting aperture was f5.6 with 1/8 power on a Nikon SB800 speedlight. As the flash to subject distance was decreased the power and aperture were reduced as required to achieve a good exposure.

The first image was taken with the flash 5m from the subject. Clearly enough light is hitting the background to make it appear similarly exposed.
The flash is now 2.5m from the subject and the background is getting darker. This happens because the fall off of light intensity is proportional to the inverse of the square of the distance.
The background of the third image is getting quite dark (flash 1m away from subject). Notice how the nose shadow is also darker. This will be because in the earlier images enough light was being reflected back from a wall to the left to soften the shadow. The 'Depth of Field' of the light is now so shallow that this no longer happens.

Now we're talking! The background is now really dark (flash 45cm away from subject) and the fifth image (below) which is taken with the flash 30cm away from the subject is nearly black.


I couldn't quite achieve black so I think I need my light even closer or my subject a bit further from the background. The ambient contribution is non existent at these settings (ISO200, 1/200th, f11) so any light is from the flash. This exercise has been a real eye opener for me as I have often wondered how to control this aspect of flash photography. The 20 minutes spent doing this exercise has taught me so much. Blasting away with TTL flash systems can be handy at times but this stuff is much more fun.
However, for the next exercise I will probably be using an inanimate object. Triggering the self timer and dashing round to get in the shot is likely to end in a knocked over lightstand.

Hard Light

The first Strobist exercise was posted last week and comprises a brief exploration of the shadows created by hard light from an off camera strobe at various angles to the subject.
The first image here shows the subject with camera directly in front with the strobe at 45 degrees to the right. The shadow on the wall is very nasty. The subject has been left close to the wall to emphasise this. The speedlight is actually a fair bit higher than the subject which can be seen by the downward slope of the shadow.

The second image shows the effect of the camera at 45 degrees to the left of the subject with the speedlight remaining at 45 degrees right. The wall shadow is equally harsh.

The third and final image shows the camera position at the same position as the speedlight at 45 degrees right. This is equivalent to on camera flash except that the speedlight is higher than the camera. Illumination of the face is more even which is not necessarily a good thing as the image will often look too flat. This is the main problem with on camera flash. The harsh shadow is still visible on the wall.

Land of the Long White Cloud

Hello from New Zealand or Aotearoa in Maori (the land of the long white cloud). This is my first post in a blog and I initially intend to use it to track my progress on the Lighting 102 course currently running at http://www.strobist.blogspot.com/.

Strobist is an excellent blog which focuses on the techniques of off camera lighting. The first assignment is coming this week and I will report here with progress.

Although I have been interested in photography for 20 years, the digital revolution has re awakened my enthusiasm. The ease with which the whole darkroom process can be reproduced in the living room has captured my imagination. Other aspects of my new path of learning in photography will be also be discussed here.