Tips on dealing with backlighting

"Backlighting" just means that there's light behind your subject. An example of this would be lining your friends up in front of a sunset to take their photo -the sun would be behind your friends, so they'd be backlit.

What happens with a typical backlighting situation is that your camera sees all that light aimed towards it, so it makes the photo darker to compensate for the excess light. The problem is, the part you want exposed properly is in shadow because of all the light coming from behind, so when the camera darkens the photo, your subject comes out almost black.

There are a few ways to fix this. You can:
* Meter off of your subject instead of metering the whole scene.
* Use exposure compensation to brighten the photo.
* Use fill flash for portraits and other photos where your subject
is small enough and close enough for it to be effective

How these changes effect your background:
If you choose to meter off your subject or use exposure compensation to brighten them, remember that you'll be brightening the entire photo. This was what I intended for the butterfly shot at the top of this post, I wanted the sky to go white behind it. But, for sunset shots this will wash out the beautiful colors of your sunset. For portraits in front of sunsets, use flash. This will balance the light of the sun with the light of your flash and will allow more color to be kept in the sunset.

Troubleshooting: Backlighting

The other day I was watching the sun rise over the lake in Chicago. It was a beautiful sight and while I was taking photos of the buildings reflecting the beautiful orange light, most of the people around me were lining their friends up in front of the sunrise and taking their photos.

There are thousands of people who do this every day, but unfortunately I think most of their photos will come out darker than they wanted. The problem is that, with their backs to a strong light source, the side of their body that face the camera is entirely in shadow. Also, the strong light source overwhelms the camera and it darkens the whole photo down to compensate, which makes those shadows even darker.

The fix? The easiest way to fix this is to turn the flash on and use fill flash to brighten your friends up to match the brightness of the sun in the background. With an advanced camera you'll have something called "exposure compensation", which is just a fancy way of saying that you can brighten or darken the photo yourself. This is the other way to fix this issue -just set the brightness up somewhere between "+1" and "+2". That should help as well.

Troubleshooting -silhouette shots aren't dark enough

The real issue here is that your camera has no idea what you are taking a picture of muchless what you want it to end up looking like. To determine how light or dark your photo will be, it's programed with a very simple goal in mind -make every photo average out to a pre-defined "average" tone (about the same shade as the palm of your hand). This works well most of the time, but not so much when you have a lot of really light or dark tones in your photo.

Here's a different way to put it: Your camera assumes that if the photo you are about to take a picture of was blurred 100%, it'd come out to be the same tone as the palm of your hand (tone = how light or dark the resulting color would be).

So, when you take a photo that's very light (like a snowman in a snow covered field) the camera has no idea why it's so bright and will darken it up so it comes out looking gray instead of white. Or when you take a picture of something dark (like silhouettes) they tend to come out lighter than you wanted (they come out gray instead of black) because the camera has to tone down all that black to make that "average tone". So, either way -with really light or really dark scenes, everything moves towards this medium-gray, but how do you fix it? It depends on what kind of camera you have!

FOR POINT AND SHOOTS OR SLR'S WITH EXPOSURE COMPENSATION:

Check your camera's manual to see if it offers exposure compensation in the mode you're using.

Exposure compensation lets you tell the camera to make the photo lighter or darker without jumping through hoops to "trick it" into doing so. Each camera works differently, but you should be able to either move an indicator on a graph that looks like this:
[-2...-1...0..+1..+2] (Nikons have the positive numbers to the left, but it doesn't really matter.)
or change the value of a number ie: "EV +1" or "EV -2".

When you move the numbers towards the negative side you're telling the camera to make the photo darker. Positive numbers mean the photo will come out lighter.

So, for silhouettes, you'll want to try maybe "-1" and see how that works. If it's still not dark enough try -1.5 or -2 -just keep playing with it 'til you're happy.

FOR POINT AND SHOOTS WITHOUT EXPOSURE COMPENSATION:

To get around your camera's "average tone" assumption, you'll have to trick your camera. If you want it darker, point it at something lighter -like the sky! Point your camera at the sky just above or next to whatever you want to be in silhouette and then push the shutter half-way to lock in the exposure. Then re-frame the shot to include whatever you want to appear in silhouette and push the button the rest of the way down to take the picture. (Pushing the shutter half-way usually locks in your focus as well as your exposure, so if your subject is close it may come out blurry -just experiment with it to see what distances work for your camera).

Getting sharp photos in low light

(Click on the photo for a larger version, the EXIF data, etc)

On Saturday I met Mike (ndisgr8) from my yahoogroup at Brookfield Zoo and we spent the whole day taking pictures. It was overcast in the morning, which made many of the indoor exhibits, which are largely lit up via skylights, very dark. As a result, it was extremely difficult to get high enough shutter speeds to get a decent photo in there. I figured this was a great example of low-light photography which everyone seems to run into as a problem from time to time, so here's a write-up about how I dealt with the situation and managed at least a couple decent pics from the ape house...

Equipment:
I was using my Sigma 50-500mm f/4-6.3 lens because this zoo gives the apes a lot of space to roam around and play, so I needed all the "zoom" I could get. For those who aren't familiar with the "f numbers" on lenses, it's included in the description of the lens for just this purpose (low light photography). The lower the "f numbers", the better the lens performs in low light. When you have a range of f-numbers like for this lens, it means that at the wide end (50mm) , 4 is as low of a number as you'll be able to choose for your aperture. At the long end (500mm), it's 6.3.

The reason this matters is as follows: The lower the aperture number, the faster your shutter speed can be. This is because as the aperture numbers get lower, you're letting more light into the camera, with more light via aperture, you can get faster shutter speeds (which allow less light to get in because the shutter doesn't stay open very long). -It's all a matter of balance.

Step 1: Aperture
This lens (the "Bigma") is not very "fast" (meaning it has relatively high f-numbers), so it really limits me when there's not much light. Because of this, I immediately put my camera on aperture priority mode and set it for it's lowest aperture number so I could get the most light possible via aperture (which would, therefore, allow the fastest shutter speeds possible).

Step 2: ISO
Before even bothering to begin looking for photo opportunities, I also set my ISO to 800. The higher your ISO number, the faster your camera will record the light when you take a picture. So, in low light you want to choose a high numbered ISO.

The cost for using high ISO numbers, however, is noise. Most noise can be removed in software later, but there's always an effect on picture quality. You should, therefore, always shoot in the lowest possible ISO setting for the lighting conditions you are in. In other words, remember to set it back down to 100 when you're shooting in daylight again.

Each camera is different as far as how much noise it produces at different ISO's, so it's a good idea to experiment and know how your camera behaves and how well you can remove the noise it produces at each different setting. This way, you'll know not to go above (in my case ISO 800) or you're risking not being able to remove the noise from the photo effectively. -I did end up moving to ISO 1600 later on in the ape house as a last resort because I wasn't getting any clear shots at ISO 800.

Step 3: Check your shutter speeds
Next, I lined up a shot and checked my shutter speed. With most SLR's you can see the shutter speed in your viewfinder. In this case, I was seeing shutter speeds ranging from 1/10 to 1/60 most of the time.

Remember, the rule of thumb is that you need a tripod if your shutter speeds are faster then the reciprocal of your focal length. That's just a fancy way of saying that if you're shooting with a 500mm lens like I was, your shutter speeds should be faster than 1/500th of a second. If you're shooting at 300mm, they should be faster than 1/300th of a second, etc. (Although 1/60th of a second is as slow as you should go with any lens because it's hard to hold the camera steady enough when your shutter speeds are slower than that regardless of how wide the lens is.)

So, I needed shutter speeds that were up to 50 times what I was getting!

Step 4: Put your camera on a tripod
I had a monopod with me just because my lens is so heavy, but I didn't have a tripod. So, I leaned the monopod against the railing and steadied it further by bracing it against side-to-side movement with my foot. A tripod would have made it more steady.

Of course, the monkeys and apes were rarely perfectly still, so even with a tripod, you'd still get blur unless they happened to stay still during the shot.

Step 5: Use burst mode
If you've done all you can with settings and steadying the camera, but your shots are still coming out blurry, your best bet is to take as many shots as possible. Many people aren't aware of it, but they jerk the camera a bit when pushing the shutter button to take a photo. That may be contributing to the blur, so if you put your camera in burst mode you can hold the shutter button down and it'll take several shots one after the other. Even if you're sure you don't jerk the camera, just by shear volume, this will increase your chances at a clear shot.

Step 6: Get creative!
I was doing all of that as well as trying to concentrate only on the apes that were in the best light and I was still having trouble getting clear shots. So, for a few shots I decided to try something different. I was shooting in RAW, so I knew that I'd have a good chance of getting most of the data out of a photo even if it was severely under-exposed (dark), so I intentionally under-exposed several photos as a last resort.

Your camera should have an exposure meter that looks like this: [-2...-1...0..+1..+2] and there's a small indicator that shows you your current exposure setting. "Zero" is normal exposure, but if you use exposure compensation to move the indicator towards the positive numbers, you're telling the camera to over-expose the photo by that amount. When you move the indicator towards the negative numbers, you're telling it to make the photo darker (under-exposed).

Darker photos are a result of letting less light into the camera, so when you move the exposure down into the negative numbers you should get higher shutter speeds. When you're shooting in RAW you're often able to lighten up the photo by up to 2 stops (which correlate with the numbers on that exposure graph on your camera).

So, I moved the exposure meter down to -2 and took a shot. I reviewed the photo on my LCD and turned on the option to view the image's histogram. I made sure the data didn't run off either side of the graph (because that indicates that you're missing data, which you can't get back even in RAW). The photo was very dark, but the histogram looked ok, so I tried a few shots like that and hoped I'd be able to "save them in software" later.

Summary:
The photo above is one of the ones I took on ISO 1600 and under-exposed by 2 stops, then "saved" in the RAW software that came with my camera (Digital Professional Pro). The "right" solution to this kind of a problem is a "faster" lens (meaning a lens with lower f-numbers), but everyone eventually finds themselves in a situation where they didn't expect to have a low-light issue and they need to do what they can with what they have. Hopefully, this write up has given you some ideas for the next time you're shooting in low-light.


Extended reading / other resources:

• How to read histograms here: http://blog.muddyboots.org/2009/02/histogram-basics.html

Photos coming out too light or too dark?

The "problem" is probably your camera's exposure meter.

Cameras are simple devices and one of the assumptions they make is that the overall tone (how light or dark the overall photo is) will average out to a set medium tone (~18% gray, which is about the same tone as the skin on the palm of your hand). If large portions of the photo will be darker than the assumed tone, the camera will think the reason for that darkness is lack of light and it'll brighten it up to make up for it. And the opposite is also true -with extremely light-colored scenes, the camera will think that the lightness is due to too much light, and it'll make them darker so they come out gray.

So, if you have a dark scene that you're shooting and you want to tell your camera that the scene should be darker than that "average tone", you have a few choices: #1. If you want accuracy, you can buy a "gray card" to calibrate your camera to the lighting conditions, set the exposure, and take the photo. #2. To get pretty close, you can meter off your hand. Or, #3, you can use trial and error like I do most of the time -just use exposure compensation in whatever mode you're shooting in:

Exposure compensation uses the exposure graph you see and use in manual mode or the "priority modes", it looks like:

[-2...-1...0..+1..+2]

..(Note that on Nikon's it's reversed and the positive numbers are on the left). There's usually a small marker under the numbers that indicates where your exposure is on the graph using whatever settings the camera is on. The "0" on the graph indicates what the camera thinks is proper exposure (assuming that "average tone"). Setting the exposure towards positive numbers means you're telling the camera to add light or brighten the photo as compared to what the camera would usually choose. And negative numbers, then, darken the photo as compared to what the camera would choose to be correct.

So, if the camera is making your snow scene turn out gray (it's coming out too dark), you need to brighten the photo, or expose more towards positive numbers. Try exposing at +1, then adjust up and down from there until you get the result you desire. On the other hand, if you're taking a photo of your black cat lying on a dark blanket, it'll likely come out too light, so you'll have to expose towards negative numbers to darken the photo. Try -1, then adjust up or down from there.

Experiment:
If you want to see just how wrong your camera's meter can be, find an all white subject (a wall or your ceiling should work), and an all black subject. Take a photo of each. Lighting shouldn't matter, but you can try adjusting the lighting to prove that it has no effect -just make sure the lighting is consistent over the entire area that you'll be taking a photo of. You can add subjects to your photo as long as they too are 100% white or black (you'd want to take a photo of a white subject against a white background, then a black subject against a black background). If you want to take it even further, you can switch subjects and backgrounds and take 2 more photos (white subject on black background and vice versa) -those should come out mostly correct since the two tones (one dark, one light) will average each other out. My photos are here if you wanna cheat ;-)

Your 100% white and 100% black photos should all come out almost the same shade of gray no matter if your subject was all white or all black. -That's what your exposure meter is designed to do! Most of the time it works just fine, but when you have a scene that's made up of extremely light or dark tones, remember this and use exposure compensation to make the photo come out as you see it instead of all gray.