Digital Imaging Corner
Robert L. Stewart, SIG Leader

Using Aperture
This month, I am going to do a tip for you to use during your shooting. Unfortunately, for most of the point-and-shoot cameras, this tip will be limited.

Large Apertures (f2.8 to f5.6)
Large Apertures, such as f2.8 to f5.6, produce shallow depth-of-field. Basically, this means the area of sharp focus in the picture will be small. This can be useful when you want to isolate the subject of your picture while throwing the background and other distracting elements out of focus. Some useful applications of wide apertures include portraits and wildlife close-ups.
Small Apertures (f16 to f32)
Small Apertures, such as f16 to f32, increase depth-of-field which means more elements of a picture, from foreground to background, become sharply focused. This can create a distinct sense of depth to a photograph, drawing the viewer into the picture. It's no surprise that small apertures are a must for most landscape photographs.
Lens "Sweet Spots" (f8 and f11)
Due to technical aspects of lens optics, the mid-range apertures of f8 and f11 often yield the sharpest images. When neither a large nor a very small aperture is needed, these are good apertures to use to maximize the sharpness your lens can deliver.
Unfortunately, most point-and-shoot cameras have a very small aperture range. It is generally f3.5 to f5.6 with a few going to f8. Trying this out and seeing what the best aperture is will be a bit more difficult also.
To test your camera out and see where you get the sharpest photos, you will need to place the camera on a tripod. We do this so you can get an exact photo a number of times with different aperture settings. You will need to set the camera in the aperture priority mode (or preferably manual). This will allow you to specify what aperture to use for the photo. Set the aperture at the widest (the smallest number). Take a photo with this setting. Now, change the aperture to the next one, and take a photo. Do this through the range of your aperture settings. Record the settings on your camera by writing them down for each of the photos.
After finishing this, move your photos into an editing program. Now, blow up the same section of the object you photographed in each one of the photos you did. Check the sharpness in each of the photos for that area. By doing this, you will see what is the best setting for your specific camera. Then, when you are taking the special photos that you want to have a very sharp photo, you know the best aperture setting to help get the image you want.
What you will generally find is that the "sweet spot" for your camera is two stops above the widest aperture.
Move in Closer
Almost any shot will look better if you take two or three steps toward your subject. Filling the frame with your subject will make a huge difference in your photos. If you cannot move closer, then use the zoom capability on your camera to take those steps for you. But, do not go into the "Digital Zoom" range of your camera.
Using digital zoom will give you the worst quality you can get from the camera. The camera is using the electronics inside of it to "crop" or "zoom" the image you see. When you do an optical zoom, you are not depending on the electronics of the camera. You are depending on the lens to do the work. This is where you will get the best quality.
When taking photos of family and friends, most people place the people in the photo showing as much of their bodies as possible. Try coming in closer, get a head and shoulder photo, or even zoom in to get just their face. With less clutter in the image, it is easier to draw attention to the main subject of the photo, the person. This works especially well when taking photos of children.
After getting the images recorded, you can always use software to zoom in by cropping the edges of the photo. This will allow you to get rid of even more of the clutter that is distracting in the photo.
Well, that is it for this edition of the Digital Corner. I hope these tips are helpful. After the first of the year, we will have our web site up and running. Keep an eye on the SIG lists for the link to it. You can contact me with any questions you may have at the following email address: robert@rlstewartphotography. Happy shooting!!