Learning how to meter using manual exposure has been the most important skill I have learned to become a better bird photographer. Manual exposure allows me to fine tune my settings for birds in flight with just a few clicks of the dial to bring out details in both dark and light colored birds.
Here’s how I go about it. I often shoot Terns on the bridge at Bolsa Chica in Huntington Beach, California. I usually arrive early in the morning when the light is low or soft.
First, I need to get my preliminary camera settings using these parameters:I set my camera using the upper limits of my the noise level I find acceptable, I set the aperture wide open, and then I choose the slowest shutter speed I think I need for the bird.
For my Canon 1DXII, 1600 is the highest ISO setting that I like to use to retain detail without too much noise. I do go higher than this in low light, but when I do, I need to do more work in post processing to reduce the noise and I also lose more detail in the shot.
I set my aperture wide open which is f/4.0 on my EF400mm f/4 DO IS II USM. With a 1.4 teleconverter, it’s f/5.6 or with a 2x teleconverter it’s f/8.0
Terns are relatively quick birds, so I want a shutter speed between 1/1000 – 1/2500 or even faster if I’m trying to get diving shots. It’s early morning and the light is low, so I set my shutter speed to 1/1000. I may go to 1/800 or even slower if there really isn’t much light. In this low light example, these camera settings: ISO 1000, aperture f/4.0, and shutter speed 1/1000, give me a basic starting point.
Meter off the green foliage:
Now, I am ready to meter my exposure off something that is readily available with the same light from which I expect to shoot the Terns and is large enough to fill in the frame. Fortunately, on the west side of the bridge there is green ground cover which is perfect for my needs.
I set my camera to evaluative metering for this gives me the most reliable results for metering. (Spot metering is too chancy for it’s easily thrown off by bright highlights or dark shadows in foliage.) Then making sure the sun is behind me, I fill the frame with green foliage and I take a test shot.
I use my camera exposure level indicator to see if I’ve exposed correctly for the green foliage. I want the exposure level indicator set in the middle. If it’s not, I make adjustments with my settings to get it there. If the indicator is to the right, the camera is advising me that the green foliage is over-exposed. If I’ve over-exposed the shot, I need to either decrease the ISO or increase the shutter speed or aperture. If the exposure level indicator is to the left saying that the shot is underexposed,
I usually will increase the ISO. I keep taking test shots and making adjustments until the exposure level indicator is in the middle. All of this preparation helps me to properly expose for the bird – in this case a white Tern.
Expose for the bird, not the background:
The green foliage serves as a reference point to expose for the Terns. My goal is to expose for the bird and not the background. I know Terns are mostly white and brighter than the green foliage (and I don’t want to blow out the whites), so I need to decrease the exposure.
To do this, I have some choices. I can either increase my shutter speed or use a smaller aperture (such as increasing my f stop from 4.0 to 5.6), or by decreasing my ISO. In this example, it’s just after sunrise and the light is dim, so to properly expose for Terns I may need to decrease my exposure from my green reference by only 1/3 of a stop.
Throughout the day, as the sun rises higher and the light gets stronger, I may need to further decrease my exposure from one to even two stops.
The process would be the same if I were trying to shoot a darker birds such Brown Pelicans. Again, I use the green bushes of my test shot as a reference. I know Brown Pelicans are darker than the green foliage, so I would need increase my exposure. And because they usually fly more slowly than Terns, to increase my exposure I can either decrease the shutter speed or increase my ISO. I can’t change the aperture because I have already set it to it wide open.
Put in the time and effort to learn manual exposure and expose for the bird, not the background. The more you practice and the more often you go back to a birding location at the same time of day, the easier it gets!
All the best ~ Patricia