Monday, 16 December 2013

12 Most Common Exposure Problems Faced by Photographers and How to Fix Them

Getting your exposure right is the first step in mastering the art of photography. Before getting on to the more creative exposure manipulations one should always learn how to properly expose each and every scene and subject in varying lighting conditions. 

common exposure problems
Photo by: Fadzly Mubin

Here’s a list of 10 most common exposure problems faced by beginners with tips on how to fix them and get properly exposed shots.

1. Camera set in the wrong exposure mode

Camera Exposure Modes
Camera Exposure Modes

This is one error that every photographer might have faced at some point in his/her career. Some cameras have a lock that prevents the mode dial from turning accidentally but most don’t. It could happen when you handle the camera (pick it up / change battery or card /clean the lens etc) even the simple act of putting it inside or taking it out of a camera bag can knock the dial out of position. Another instance is when you hand over your camera to another person who is in the habit of shooting in a different mode and forgets to put it back before handing the camera back to you. This could also happen if you are in the habit of regularly shooting in one of the semi automatic modes like aperture priority and occasionally switch to manual for specific purposes. If you forget to switch back the camera mode then you’re in trouble.

The best solution to get over this problem is to make it a habit to check the shooting mode every time you pick up your camera, also when composing your scene, before you press the shutter all the way down do check where your exposure meter is; is it indicating a right exposure or not. This way you’ll immediately know if any of your settings are askew.

2. Exposure compensation set incorrectly

Camera Exposue Compensation
Camera Exposue Compensation

Setting exposure compensation to suit a scene and forgetting to reset it is yet another common exposure mistake. If you find that your camera is consistently producing brighter or darker images than normal; check the exposure compensation settings and reset it if it’s wrongly set. The trick to avoid this problem is to check the metering and exposure compensation settings before you start shooting.

3. Wrong ISO Settings

Camera ISO Settings
Camera ISO Settings

Shooting in low light situations without a tripod often demands high ISO settings, but if you forget to set you ISO back to low values when you shoot outdoors in bright light you will find unusually fast shutter speeds or narrow apertures or a combination of both suggested by the cameras exposure meter. Sometimes the problem is much worse and the camera does not allow you to take a picture either because the maximum shutter speed is exceeded or the narrowest available aperture is not small enough. The opposite happens if you have set your ISO to very low value and try shooting in very dimly lit situations; the camera meter will return very slow shutter speeds which are not possible to handheld and also render any moving subject blurred.

4. Wrong Metering Mode

Camera Metering Modes
Camera Metering Modes

Your camera is equipped with many metering modes to help you properly expose your subject in different lighting conditions. Some are general purpose modes (evaluative / matrix) and could be used for almost all types of subjects/scenes. But some others are special purpose modes; a good example is the spot metering mode which is like a razor sharp weapon. If you set your metering mode to spot metering and forget to reset it you will see your cameras meter suggesting wildly variable exposure settings for the same scene depending on where it takes the reading from. Spot metering mode only measures a very small area and if this area falls on a highlight the overall scene will be underexposed and if the metering area falls on shadows then the overall scene will be overexposed. The trick to avoid such problems is to remember to set your metering mode back to evaluative or matrix metering.

5. LCD Brightness

Camera LCD Brightness
Camera LCD Brightness

Relying on the LCD of your camera to judge your exposure could often cause problems; firstly LCD’s have a mode which automatically adjusts the brightness levels to suit the ambient light, and if this feature is turned on, the camera automatically brightens or darkens your LCD display (depending on ambient light) making it hard to judge exposures. Secondly as LCD is difficult to see in bright sunlight most photographers set it to a brighter setting, either ignoring or not knowing about the importance to calibrate the LCD to match that of their computer screen on which they edit their images. This causes the camera to artificially brighten the display misleading the photographer to believing an actually underexposed scene is properly exposed. Or the opposite could be true: the LCD screen brightness is too low and your pictures look dark. The trick to avoid being fooled by the image you see on the LCD is to cross check your exposure using the histogram. Also it will be a good idea to turn on the “blinkies” that warns one of blown out highlights. A LCD Hood will come in handy too. HoodLoupe.

6. Underexposure when photographing White subjects

Digital cameras have their light meters calibrated so as to average out the highlights and shadows in the scene and render it as middle tone gray or 18 % gray. But when you shoot a scene or subject that is predominantly white the camera is fooled to believing that it is a gray subject in a lot of light and to expose it properly as gray the camera will actually underexpose your white scene, making your snow filled landscape as one covered in ash. The trick to get over this problem is to apply the right exposure compensation; depending on the subject / scene usually a setting of +1 or +1 ½ EV should do the trick.

Keep an eye on your histogram; it could be a good guide as to the amount of compensation to be set and to verify that there is no clipping occurring.

7. Overexposure when photographing Black subjects 

Similar to the above point when photographing predominantly black subjects, the cameras meter is fooled to believe that it is a grey subject in dim light and will try to compensate for the loss of light and expose your blacks as middle tone gray. The trick to get your exposure right is again the same; apply the right amount of exposure compensation. Depending on the scene a setting of -1 or -1 ½ Ev should do.

Keep an eye on the histogram to make sure you are not clipping shadow details.

8. Underexposure when photographing back-lit subjects

When photographing subjects that are lit by light coming from behind them and towards the camera, one thing to remember is that the difference in light levels on your subject and on the background is too high. And when the camera averages these two extremes it usually underexposes the subject. However this could be remedied by applying some + exposure compensation or changing your metering mode to center weighted or spot metering. These modes give greater emphasis to what’s in the center of the frame when calculating exposure settings. If your camera allows you to link spot metering to the AF point that is active you could use it to correctly expose subjects which are off center too. Check your camera manual to find out if your camera has this feature; it should be in one of the custom settings.

9. Underexposed foreground in a landscape

When shooting outside especially landscapes photographers face a very difficult situation. Usually the sky will be much brighter than the land, so when they try to expose the sky correctly, the land in the foreground will be underexposed.  To correct the exposure difference between the sky and the land photographers make use of GND (graduated neutral density) filters. The filter is attached so that the dark part is placed over the sky, and the clear part over the foreground. GND filter are available in different strengths like 2,4,6,8 and 10 the numbers represent f stops and is the amount of light they block in the dark part. The greater the contrast difference is the darker the GND filter needs to be.

10. Overexposed sky/clouds in a landscape

Just as the point discussed above in a high contrast situation, when the camera tries to expose the land in the foreground properly the sky will be blown out. Again the same tool GND filter should be used to rectify the situation.

11. Underexposed Shadows and Overexposed Highlights

When photographing a high contrast scene, if you observe that both your highlights and shadows are clipping then you should understand that the difference in brightness levels in the scene is well beyond the dynamic range your camera is capable of capturing. Human eyes have much greater dynamic range than digital cameras and so we do not see blown out highlights or clipped shadows with our naked eye but when we try to photograph the scene it’s a whole new game. The trick to capture the entire dynamic range in the scene is to take multiple exposure one exposure for the highlights, one for the mid tones and one for the shadows and later combining them all to form a single image in image editing programs. This technique is called HDR. To know more about these techniques visit the tutorial here.

12. Shutter speed too slow to freeze movement

The first variable we set when photographing a scene will be the aperture, as it affects the depth of field and thus how the picture appears. However when trying to get a proper exposure for our scene we often fail to notice the shutter speed which plunges way below the handholdable speeds. What happens is blurred images either due to camera shake or simply the shutter speed being not fast enough to freeze movement. To avoid this from happening, make sure you use a tripod if the subject is still or use a flash or high ISO when photographing moving subjects in low light conditions.

One piece of advice for beginners that could save you from a lot of situations is to use the automatic exposure bracketing feature of your camera whenever you are not sure about the exposure.

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