Wednesday, February 17, 2010

Project 61

The final project in artificial light is a strange one, I am not really sure what the objective is other than to try using a camera's built in flash or an external flash gun.  Almost all modern cameras have built in flash with TTL metering as a standard, perhaps this section dates back to an earlier age.

On the other hand my 5D2 is a new camera that does not have built in flash, however, I have a number of external  Speedlites that I use whenever I need extra light.  These TTL with the camera and allow flash exposure compensation as well as full tilt and swivel.  I also have a remote transmitter and off camera cable to move the light to more or less any position I wish.  Although recently I have been experimenting with low end studio flash, combining several speedlites in umbrella stands and with softboxes/light tents provides excellent control for still life, particularly for smaller subjects.  I originally purchased the speedlites as fill flash for wedding photography and portraiture, but have been pleasantly surprised by their versatility.

For this project I have decided to explore the function of a single camera mounted 580 EX, with a efw different subjects to illustrate some of the basic principles of flash usage.

My first pair of images is of my CD collection with the flash facing directly forwards

There is a strong unpleasant reflection from the CD cases caused by the forward facing flash.  This is a problem with shooting a very shiny surface

Tilting the flash upwards by around 60 degrees greatly improves the image and produces a much better lit image.

The next image is of a new plant sitting in a window, first of all with no flash

The image is clearly just a silhouette.  Adding flash does not change the background exposure but illuminates the foreground.  However in the following image I am square on to the window and the flash is reflected directly back

Moving around by a few degrees to change the angle eliminates the reflection and greatly improves the image

The lesson is to be very careful of any reflective surface square on to the camera.   A similar image pair enhanced by the addition of fill flash is the following image of my cat sitting on her cat tree, and not very sure about this strange flashing thing.  Again the background exposure does not change as I have not changed the exposure on the camera between shots

There is a little reflection here, but it is not too noticeable.  The next image pair shows the problem of forward facing flash, the creation of harsh shadows

Bouncing the flash of the ceiling, produces much softer more balanced light

Once again, the exposure on these two images is identical, all that has changed is the angle of the flash gun.

My final two images are of some glass on the top of a shelf.  The direct flash creates harsh shadows, but also unpleasant reflections.  Pointing the flash upwards completely changes the image

Changing the angle of the flash is a great tool, however, it only works when there are conveniently positioned surfaces (preferably white or grey) to bounce the light off.  Otherwise it is necessary to take the light off the camera.  My favorite approach to this is that taken by underwater photographers, in which the flash is positioned on articulated arms and attached to the camera via a sync cord.  The following image is the same set up that I use, housing and strobes, although this is not me in this case

This enables the light to be positioned arbitrarily within the limits of the cord length.  The water provides support for the weight of the strobes, this would not work on land!

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