Consider this! You have spent a considerable amount of money to travel to a location, where you can photograph puffins in flight.
In comes a bird on a landing approach, it flares out to land and its bill is stacked full of sand eels. You have tracked it on the way in.
You let rip with a small burst, your timing is immaculate . The resulting image of the bird is sharp and well exposed even down to the
sand ells eyes. However, the flipin sky is BURNED OUT how infuriating! Sometime I will take an image PERFECT SKY other times where
has the flipin sky gone. I don't understand why! This is definitely a weakness of mine! Please can you help me?
It would help to see specific photos where you've had this problem but it typically results from a bird with bright feathers that's relatively small in the frame and flies in front of a dark background.
Whether matrix or center weighted metering the camera looks at a fairly large region to all of the frame and tries to find a decent exposure for all of what it sees. If a brightly feathered bird is relatively small in the frame and it flies in front of a darker background the metering will be overly influenced by that dark background and since all uncompensated metering works on the assumption that the world is 18% gray it will brighten up the image. But if in fact that background really should be much darker than 18% gray AND your main subject (the Puffin) has areas of bright feathers, those brighter areas will tend to get blown out. The same bird up against the sky will likely be exposed fine or could even be under exposed because again the relatively large sky/cloud area can be much brighter than 18% gray and the camera will often be influenced to darken everything accordingly.
Matrix metering usually does a much better job in these kinds of situations than a pure center weighted metering approach but extreme situations like a smaller white subject (or small portions that are white) against a very dark background or smaller black subjects against a bright background are difficult for auto metering. Spot metering just on a neutral tone area can work but that is tough with action shots and generally not the way to go.
The larger your subject is in the frame the less the exposure will be influenced by the background. IOW, matrix metering tends to do a better job with frame filling portraits than more distant shots though Puffins are somewhat tough subjects because they're largely dark with some very bright areas. Something like a nearly frame filling Great Blue Heron is much easier from a metering standpoint as it's mostly neutral tones. Wedding day photos with a white dress next to a black tux in harsh mid day light are a classic example of tough metering and Puffins are a bit like that, but they move a lot faster
There's a few ways to deal with it:
- The easy but crude approach is if you check histograms or image review blinky's in the field and see that you're overexposing bright areas, you can dial in some negative exposure compensation as in -.3 to -.7 stops or sometimes more. That can give you more margin to save highlights but in more neutral conditions where either the birds are much larger in the frame or the backgrounds aren't so dark that will tend to under expose images though that can often be easier to fix in post with modern high dynamic range sensors but it's not ideal from an IQ and noise standpoint to just blindly dial in exposure comp. Ideally you'd compensate for each changing scene as needed.
- A more sophisticated approach when you see shooting conditions where the subjects could be big or small in the frame and the backgrounds could vary from neutral to very dark or very bright is to run full manual exposure mode with manual ISO setting and pre-meter the scene to get a good exposure. This is one place where spot metering or at least a couple of test shots can help you dial in the correct manual exposure for the given light. This works great if the light doesn't change too much but if the light does change a lot (e.g clouds coming and going or sunrise, sunset times) then you should re-meter and reset your manual settings (often just an ISO adjustment) to account for the changing light. But with the camera set to full manual with a good exposure it doesn't matter if your puffins are frame filling or tiny or in front of dark rocks or just out on midtown green grass, as long as the light is steady each shot will be exposed the same.
- Another approach if the backgrounds and subject sizes aren't changing too much but the light is changing is to run an auto mode like Manual Exposure/Auto ISO or Aperture or Shutter Priority which will account for changing light levels but then it's up to you to either dial in a constant exposure compensation based on the typical scene if needed or be ready to change exposure comp on the fly as the scene changes, like when the Puffins move from landing on green mid tone grass to landing in front of dark rocks.
But in the end you as the photographer have to pay attention to either the changing scene (e.g. dark backgrounds) or the changing light levels as the camera can track one or the other pretty well depending on which of the above choices you make but it can't automatically adjust for everything as it has no real idea what your intent is or what your subjects and backgrounds are. That can be frustrating when the action is hot and heavy but it's part of mastering field photography skills.
I've used all of the approaches above in various situations and switching back and forth between Manual Exposure/Auto ISO and Manual Exposure/Fixed ISO is really easy on a lot of cameras including the latest crop of pro and semi pro Nikon DSLRs. Similarly dialing in exposure comp is really easy and can generally be done without having to take your eye away from the viewfinder. If this seems daunting, the easiest first step is to get used to checking your histogram or blinkIES (dang spell check won't let me spell that without the caps
) and adjust as needed in the field.
