F22 is a small aperture setting, while F2 is obviously a very large aperture setting.  With this lens on a modern digital SLR camera (or D-SLR), the aperture setting is controlled by the command dial when the camera is in A or Av mode.  You can access all four creative controls by simply spinning the command dial with your thumb - if you go to small f-stops (F16 or F22) you apply two creative controls - greater depth-of-field and slower shutter-speeds.  Now, you may need only one of them - but you get both.  If you spin the command dial to larger f-stops (F2, F2.8, or F4) you get limited depth-of-field and high shutter-speeds, again, you may need only one but you get both.

     The simplicity of Aperture Priority Mode is that as you become accustomed to using it, your thought process will move quickly to just thinking about applying a creative control to a particular image.  You spin the command dial with your thumb, and your done - you never break concentration with your subject.  This is the simplest way to learn to control the creative abilities of your camera.  You don't have to look up from the viewfinder to change exposure program modes, you don't have to manipulate any other menu items, and you don't have to think about anything except your subject - and spinning the command dial with your thumb. 


      FOUR CREATIVE CONTROLS easily accessible in Aperture Priority Mode

     Those are our four creative controls.  All the f-stops that the camera can set could be used by you, the photographer, to decide on the look and feel of the photograph.  Simply using your thumb to rotate the command dial will deliver your choices to the camera - and you are in control of the creative process of photography.

     Here are examples for the different creative controls we can make in Aperture Priority Mode, and why I made them:

 

Slow Shutter-Speeds Slow shutter-speeds were obtained by choosing a small f-stop, in this image of Archangel Cascades in Zion National Park the f-stop was F19, with a shutter-speed of nearly 1 second.  That long exposure created a nice blur in these step-down waterfalls,  and a by-product of F19 was also great DOF.  RAW file processed in Photoshop's Adobe Camera Raw.  ISO 100 and -.5 eV.

High Shutter-Speeds The most important element of this image was to try to stop the action of the bald eagle flying, to freeze it in flight and create a flying portrait.  This was accomplished by going for the maximum large f-stop of my 500mm lens, which is F4 - and this gave me a shutter-speed of 1/1500 second.  Exposure compensation was -1 eV to protect the white head feathers from burning out.  That increased my shutter speed from 1/750 to 1/1500.  ISO 200.  In this case F4 provided selective DOF as well, nicely blurring out the background water and distracting cattail reflections.  RAW file processed in Photoshop's Adobe Camera Raw.

Great Depth-of-Field This image of rock formations at Sidestep Canyon in the Grand Staircase-Escalante National Monument in Utah is a good illustration of needing maximum DOF.  The image was taken at F19 and 1/125second, ISO 100, and -.5 eV compensation.  I used the concept of Hyperfocal Distance to focus in the foreground to achieve maximum DOF at this F-stop.  The shutter-speed didn't matter to me since I was shooting on a tripod and using a electronic cable release.  RAW file processed in Photoshop's Adobe Camera Raw (ACR).

Selective Depth-of-Field Shot at F4 to achieve limited DOF, this image could have easily been taken at F8 - except for the fact that the increased DOF would have brought the background into greater focus, thus revealing that the white areas on the sides of this image around the American Kestrel are really white siding on condominiums.  I sacrificed increased sharpness of the Kestrel and better DOF in order to obscure those homes.  My image suffers a little (the tail feathers begin to blur) by my choice, but benefits greatly in hiding those homes.  ISO 200 at -.5 eV and 1/1250 second shutter-speed.

     These four examples show the extremes of f-stop selection.  I'm very aware that the sweet spot of most lenses (for sharpness) are the F8 and F11 f-stop settings.  Whenever possible, and when creative considerations can still be met, I work my f-stop settings towards those choices.  Also, I know that distance to subject also greatly effects the choice I might make in f-stop selection.  But regardless of the reasons,  shooting in Aperture Priority Mode makes it easy for me to take the kind of images I want to take, I just have to use my thumb.

     The footbridge that crosses from the parking lot is a great spot to photograph the numerous birds both fishing and flying up and down Bolsa Bay.  It is particularly good around sunrise on days without fog.  Hundreds of species of ducks, shorebirds, wading birds, and raptors spend at least part of their lives here.  There is a trail that winds around the refuge that is 1.5 miles long that gives you access to ponds and marshes from various points.

     The second map shows some trails (in red) that are accessible from Bolsa Chica Rd.  If you drive back to Warner Ave and head east you come to Bolsa Chica Rd at a light.  Turn right and go until the road takes a sharp right.  Park there and follow the hiking path down to the ponds.  I've photographed Peregrine Falcons, Sharp-shinned Hawks, Coyotes, Osprey, and numerous songbirds - as well as the usual shorebirds, along these paths.  There is also a copse of palm trees with Great Blue Heron nests, and an occasional Great Horned Owl nest in the branches.  This is an older Google Earth map because all the construction area is now homes, and the well-worn, landscaped walking path is easy to follow.

     Here are some images from Bolsa Chica Ecological Reserve:

American Wigeons	American Avocets
Endangered California Clapper Rail	Great Blue Herons
Great Egret	Red-breasted Merganser