Graphics Reference
In-Depth Information
onto a single frame. These photographs are achievable by the use of strobe
lighting in a studio environment, though similar results may be achieved by
the layering of images using Photoshop.
Using a DSLR, the photographer has the option of a fully manual mode,
semiautomatic modes, or fully automatic modes. They all have their
advantages. If you choose a fully automatic mode, the camera selects the
appropriate combination of shutter speed and aperture to ensure a correctly
exposed image and focuses on the subject. Other semiautomatic settings
allow you to prioritize either the shutter speed or the aperture setting. If you
select the shutter speed as priority, the camera selects the aperture setting
required to create a correctly exposed image. If the aperture is set as a priority,
the camera will select the appropriate shutter speed to achieve a correct
exposure. It is also possible to allow the camera to automatically focus on
the subject, though this could result in the camera focusing on the wrong
element in the frame. In the fully manual mode, the photographer determines
all settings as well as focus. This approach does offer maximum control, but it
also requires more effort. In very pressured situations, when the photographer
needs to act quickly, it might not be the best option. Each situation requires
its own approach.
You need to give some consideration to the desired resolution of your images
and the format in which you want to use them. If you intend to print your
images, you will need to increase the resolution, though the file size will
increase along with it. The higher the resolution, the better the quality of
the image. Unless you are preparing work that is intended for commercial
print purposes, images that range between 150dpi to 300dpi should be high
enough for most personal uses. The resolution is one of the determining
factors in the file size. The other is the area size of your image. If you intend to
use the images only as screen-based resources, 72dpi should be adequate. It
will certainly make for much smaller file sizes while maintaining decent quality.
Photoshop is a very powerful tool with very many features and uses.
Unfortunately, there is simply no room here to do anything other than discuss
this tool in the simplest of terms. You'll find some first-rate texts out there that
deal with Photoshop and photography. Once again, in the resources section
I list a few that I have found very useful.
Photoshop can be used for a wide range of purposes though I have restricted
the discussion here to the way I use it for processing images for the purpose
of action analysis. I also use it extensively for my other photographic work and
my animation but in very different ways. For action analysis I simply use it to
process my digital images for printing or for screen-based reference. I never go
beyond making the images as clear as possible, and to that end I rarely give the
making of these images any purely aesthetic considerations. For the most part,
when I use Photoshop to process images for action analysis, I crop the image to
the frame format I require and change the contrast, image, and resolution. The
batch processing of multiple images using the actions facility in Photoshop is
