How to Shoot Using SLR
6 Sep 2007
For those who are new to SLRs, the variety of settings and options available can be quite confusing. To help clear some of that confusion I've written a tutorial on how to take photos using an SLR camera. Most of the features I discuss can be controlled on point-and-shoot cameras as well, so it's worth a read even if you don't own an SLR. I will discuss all of the different variables when taking photos and how to use them, when to use them and when not to use them. Firstly, though, I will show you how to identify a poor quality photo.
The main problems that most photographers try to avoid are blurriness, over or under exposure and a thing called 'noise'. Most people have seen a blurry photo before, and most have seen a photo which is too dark or too light (that's under and over exposure), but not everyone can tell whether a photo has too much noise. Noise is that little speckled, dotty stuff that sometimes becomes noticeable if a photo is taken where there is not enough light. Noise can be difficult to remove using Adobe Photoshop or another editing program without losing detail in the photo, so it's always best to avoid it at all costs. Blurriness can be fixed in Photoshop (depending on how blurry the photo is), but usually not without adding noise to the photo. As with noise, it's always best to avoid blurriness. Over or under exposure can, in most cases, be easily fixed by altering the brightness or contrast of a photo in Photoshop, so you don't have to worry about it as much. The next section explains how to avoid all of the above problems using the different controls of your camera.
The following are the main controls of a camera:
- Shutter speed
- Focal Length
- White Balance
Aperture, shutter speed, ISO and focal length affect how much light goes into the camera lens in different ways. Your camera's manual should have a diagram on the first few pages which explain where the buttons for changing these settings are. You might want to look up the name of the setting in the index of the manual if you want to know how to change it in more detail. Be sure to set your camera to Manual mode (look for the M on the mode dial) before attempting to change any of the settings, as other modes might not allow you to change the settings.
Aperture determines the size of the opening that light will pass through when you take a photo. Aperture is measured in f-stops or f-numbers, which is abbreviated to just 'f' and usually added as a suffix or prefix after the f-stop number, e.g. 22f or f/1.4. The lower the f-number, the 'wider' the aperture, and the more light that the camera's sensor and eventually the photo is exposed to. If you are shooting in an area where there is little light, such as indoors or at night, you will need to expose your photo to all available light by using the lowest possible aperture. If you don't do this, your photo may be blurry, contain a lot of noise, or turn out too dark or even black.
Most SLR cameras have a light meter. When you focus your shot, you will know if there is too little or too much light by reading the meter. The indicator should be as close to the middle as possible before taking a shot. If it is in the negative area, there is not enough light. If it is in the positive area, there is too much light. There are a few ways to change the amount of light that is let into the camera, but in instances where there is too little or too much light, you should always change the aperture first. However, under or over exposure can be used intentionally for artistic purposes, so there is not really any universal 'right' or 'wrong' exposure.
Another factor which aperture affects is depth of field. Depth of field is the range of distance in the area of a photo which is acceptably sharp or in focus. For example, a photo with a small depth of field would show most objects (apart from the subject that was first focussed on) as blurry or out of focus, while a large depth of field would exhibit an image where most objects are in focus.
If you want to experiment with different apertures without having to worry about the other camera settings, set your camera to Aperture Priority mode (represented by Av on the mode dial). This will make the camera adapt all other settings to whatever aperture you select.
On a camera, the shutter is like a small slider which is closed when no photos are being taken to prevent damage or dust collecting in the interior of a camera. The shutter opens and closes to expose the camera's sensor to light and capture a photo. The faster/higher the shutter speed, the less light that is let into the camera and the lower the chance of getting a blurry photo. Shutter speed is measured in fractions of a second (e.g. 1/800th of a second), but on most cameras only the denominator in the fraction (the 800 part) is shown. Once you get down to about 1/200th of a second, you may need a tripod to prevent camera movement from causing a blurry photo. The shutter can be manually set to very slow speeds (e.g. 3 seconds, which would sometimes appear as 3/1) for taking photos of things like fireworks (although the fireworks are very bright, the majority of the photo is dark sky, and you need to use a long exposure to get the entire fireworks burst), or for long exposure shots of moving objects or lights.
If you want to experiment with different shutter speeds without having to worry about the other camera settings, set your camera to Shutter Priority mode (represented by Tv or S on the mode dial). This will make the camera adapt all other settings to whatever shutter speed you select.
The ISO setting on a camera should be your last resort when attempting to increase the amount of light entering the camera's lens, as it can increase the amount of noise in a photo greatly. You might have seen descriptions on film packaging such as "good for action shots" or "good for daytime photos". This usually refers to the ISO of the film. The higher the ISO, the faster the film and the less light that is let into the camera, which sometimes results in noise. For example, an ISO of 100 would be great for outdoor shots as doesn't let as much of the harsh sunlight expose the sensor. A high ISO could be used in low light areas or for taking action shots. For example, a sports day carnival you can expect to use an ISO of 800 of even 1600. Any lower and the photo may turn out blurry.
Focal length or focal distance is the distance between your camera's sensor (the part of a digital camera that captures the light for the photo) and the focal plane (the area of a photo which is in focus). Every camera lens has a focal range printed its rim, which states its minimum and maximum focal length, e.g. 18-55mm. Some lenses don't have zoom, so only one number is printed on the rim of the lens. Obviously, the shorter the minimum focal distance, the closer your subject can be to your camera lens before your lens won't be able to focus on it. Lenses with a very long maximum focal length (e.g. 300mm) are typically called telephoto lenses and are used to take photos of things such as wildlife, where it's almost impossible to get physically close enough to get a good shot. Macro lenses can be bought which have a very short minimum focal distance, so that you can take close-up photos of things like small insects or jewelry.
You shouldn't need to change this one if your camera has an automatic white balance option, but I'll explain it anyway. The white balance setting helps to neutralize white colors in a photo. For example, if you take a photo indoors, some lights may give photos a yellow or orange tinge. You may need to set your white balance to 'tungsten' white balance to add a blue tinge to the photo and help neutralize the yellow tinge that the lights created. Other white balance options have fairly obvious uses, e.g. the daylight white balance is used when outdoors.
Some extra info
EXIF (Exchangeable Image File Format) Data is like a little profile that your camera attaches to each photo you take. It stores information such as:
- When the photo was taken
- What camera it was taken with
- The camera brand
- Camera settings used in the shot e.g.
- shutter speed
- focal length
- white balance
Some photographers remove this information from their images before posting them online, as they don't want others to know what settings they used. I like to leave my EXIF data intact so that others may benefit from it. Be warned, though, some edited images still have the EXIF data attached, so the image may not necessarily reflect the settings stated in the EXIF data.