Harsha asked me to provide a short Blog on how I set up exposure for photographing Bald Eagles at Lock and Dam 14. This is not an easy endeavor to undertake. The migratory eagles are at Lock and Dam 14 from December through February. The skies are usually over-cast 90% of the time. Under these circumstances, selecting the correct exposure to photograph eagles in flight is a challenge because they have very white heads and tails with extremely dark bodies and little light to work with.
Like many of you, bird photography is my recreational passion. Setting exposure in shifting light is a continual challenge and a learning experience which I’m forever trying to improve.
Exposure generally consists of three elements: aperture, shutter speed, and ISO. However, in my opinion, how the camera measures light and White Balance (WB) are two other factors that contribute to a well exposed photograph.
Utilizing a Canon EOS-1D Mark IV and a Canon EF 500mm f/4 L lens, I start off with the following settings:
Shutter Speed: 1/1600 of a second
Light Meter: Evaluative, Partial, Spot Metering
White Balance: Auto WB
ISO: I try to use the lowest ISO possible which is usually 400, but I will adjust the ISO from 100 to 1600 depending on the available light. Higher ISO settings often tend to become “noisy” or “grainy”. Each model of camera has its’ own limitations. The newer cameras like Nikon D800, Nikon D4, Canon 1DX, and Canon 5D Mark III are producing some excellent noise free photographs at extremely high ISO settings. (More on this later in “Putting it all together“.)
Shutter Speed: I like to use 1/1600 of a second to help freeze the eagles wings and to decrease camera shake. Remember, just because you might be using a tripod, there is still shaking of the camera. Eagles are not Hummingbirds, they have a relative slow wing beat. You can freeze their wing motion with as little shutter speed as 1/1000 of a second. (More on this later in “Putting it all together“.)
f/stop: I start out using an f/stop of 5.6. The widest aperture of my 500mm lens is f/4. I’m not to concern with Depth of Field, because telephoto lenses give very shallow DOF. (More on this later in “Putting it all together“.)
Light Meter: I have used Evaluative, Partial, and Spot Metering in the past. If you can hold the “Spot Meter” on a flying eagle, that’s probably the most accurate, however, I have been using Evaluative Metering lately because I can’t hold the “Spot Meter” on the moving subject. Heck, I’m lucky to keep the bird in my frame. In my opinion, each of the above metering systems end up taking a light reading of the background usually the sky or water. (More on this later in “Putting it all together“.)
White Balance: I use Auto WB about 95% of the time. White Balance can be adjusted in Post Processing as needed, but usually, it’s pretty much on the mark.
Mode: I use Manual Mode probably 90% of the time. The other 10% is either Aperture Priority or Shutter Priority. (More on this later in “Putting it all together“.)
I then point the camera at the Service Lock and take a light reading on the gray paint of the doors. This light reading gives you a perspective of the available light. I use the color of this door to obtain a “Neutral Gray” light reading. It may not be an exact rendition of a “Neutral Grey” exposure card, but it’s close enough. “Neutral Gray” can be thought of as a color in the middle of absolute black (no light at all) and absolute white (100% of all colors in the light spectrum). Kind of in the middle of the Eagle’s white head and their dark body. Hymmmm.
Looking at the meter, I determine what the exposure is. It could be under-exposed or over-exposed. The degree of exposure is also shown by the swing of the pointer into the positive or negative light meter bar.
Putting It All Together
The first exposure correction that I make is usually to adjust the ISO. I adjust this setting so that I am “over-exposing” a bit.
I generally expose for the white of the eagles’ head. Why? Because when an eagle is in flight and the background is the sky, “lightmeters” will read the sky not the eagle, thus under exposing the bird. If the “light meter” is set in the Spot or Partial Metering Mode, you still get a light reading of the sky because of the difficulty in holding the spot on the bird, therefore I have been using the Evaluative Metering Mode.
As stated above this is the mode that I use most of the time. I have my camera setup so that I can adjust exposure from the neutral position with a flick of my index finger, controlling the f/stop using the Main Dial next to the shutter release, or by thumbing the Quick Control Dial on the back of the camera for shutter speeds.
Using the Main Dial, I can open up the exposure by clicking it to the left one or two times from f/5.6 to either f/4.5 or f/4 or closing the aperture down by clicking it to the right. The “sweet spot” of my 500mm lens is at f/4.5, however, by originally setting the f/stop to f/5.6 I have more room to increase or decrease exposure at will. Usually, I only have time to adjust it by one or two clicks either way.
Using the Quick Control Dial virtually does the same thing for exposure, but utilizing the Shutter Speed. By setting the original shutter speed to 1/1600, I then can then decrease it to 1/1250 or 1/1000 or up to 1/2000 well within good wing freezing speed as needed.
After setting the “Neutral Gray”, you can set your camera mode to “Shutter Priority”.
For the most part, this will give you some good photos, however, by sliding the exposure wheel to the right 1/3 to 2 f/stops you will over expose the photo to compensate for the light meters‘ reading of the sky. This then will give you a better exposed eagle, but the sky will be very bright. I’m usually more concern with good exposure of the bird, not the sky.
This mode basically works the same way as the Shutter Priority except you are dialing in the Aperture that you desire.
I use Shutter and Aperture Priority when the light is constantly changing. For example, on a sunny day with a lot of Cumulus Clouds drifting by, the subject (eagle) can fly into and out of either the shadows of clouds or into or out of the sunlight.
Auto ISO is becoming a very good tool. I think it’s best used in either Shutter or Aperture Priority.
Photographers at LD 14
A Couple of Helpful Hints
1. Under exposure causes “noise”.
2. Looking at the histogram also helps to a degree, but remember, you are exposing for the bird, not the sky or water.
3. A photograph that is a bit over exposed will give you less noise and more color to work with. A balance of “Black” and “White” is really what exposure is all about. Remember, “Black” is void of color and “White” has all colors. To dark gives you noise and less to work with in Post Processing, to much light is like looking at the sun, it’s blinding, and called “Burned Highlights”.
4. After you have everything set, take a few photos of the seagulls. This will show you what your exposures are like.
5. The light is always changing, so constantly check your exposure either by metering the gray door, or shooting gulls.
Larry ‘s first camera was a “Kodiak Instamatic“. He purchased his first SLR camera in 1968 while serving in Viet Nam as a Combat Medic with the 9th Infantry Division of the U. S. Army. In those days, Canon had just incorporated a light sensing system in the Canon FT QL SLR 35mm camera which cost $150.
After returning home, Larry graduated from college and later became a Registered Respiratory Therapist. The majority of his working career was dedicated to directing the Cardiopulmonary and Neurodiagnostics Services at Agnesian Healthcare in Fond du Lac, WI. He initiated a hospital based Durable Medical Equipment company, a Sleep Disorders Center, a family practice clinic, along with many other endeavors.
The joy of his life is interacting with his two adult daughters, Sarah and Elizabeth and both granddaughters. His partner, Gloria keeps him on track and greatly encourages his photography.
Larry’s passion for nature photography keeps him “Chasing the Light” at home in Silvis, IL and throughout North America and the Caribbean. His favorite subjects are Eagles and Hummingbirds. When in the Caribbean, while Gloria soaks up the sun on the beaches, Larry is out scouting the islands with camera in hand for indigenous hummingbirds. It’s always a thrill to travel to new places with his photo friends. Nature photographers have a deep connection that is always a learning and joyful encounter.