The essential features of every digital camera

Today's digital camera features allow us to perform tasks we could only dream of a few years ago. And they're all within a very neat, ergonomically designed little package. 

Unfortunately, that's where the trouble starts because today, even the 'simplest' digital camera comes loaded with so many features, functions and gimmicks that anyone but the most tech-savvy camera geek is likely to be overwhelmed.

Remarkably, most photographers—even professionals—will never touch many of these digital camera features. The majority will only be used once when the camera is brand new and needs to be set up. 

A further collection will be used from time to time, in special situations or for unusual subjects or lighting. 

There are only a handful of functions that you will use throughout a typical session, which lie at the real heart of the photographic (and sometimes creative) process. 

They are almost universal to every digital camera type on the market, including:

• compact
• bridge
• mirrorless
• DSLR

All that varies from one camera model to another is how you access and use those features.

Here you'll find everything you need to know about the essential digital camera features and how to use them. You'll just need to figure out how to access them on your particular camera—with the camera's manual's help if necessary. 

 

ISO: the sensor's sensitivity

This much-used acronym stands for the International Organization for Standardization, and in photography, it refers to a measurement of the sensitivity of the camera's sensor to light. 

This is measured along an arbitrary scale, usually with a range of about 100-5600 on consumer camera models, up to several thousand more for professional models. 

The higher the number, the more sensitive the sensor is and the less light it needs to capture an image. It might seem a good idea to keep the camera set permanently on a high ISO setting, but this is not so. As the ISO setting rises, image quality deteriorates due to increasing graininess, usually called 'noise'.

On the vast majority of cameras today, from smartphone cameras right up to professional-level DSLRs, the camera is set by default at 'Auto ISO', which means that the camera automatically chooses what it considers the best ISO for the lighting conditions.

As a result, the ISO will rise significantly in low light situations, enabling you to keep shooting with the camera hand-held (rather than on a tripod), but with the trade-off that the images will be of much lower quality due to the rising level of high ISO noise. 

This auto-ISO is fine if all you want is photographic snaps, but if you want to be able to shoot high-quality creative photography, you must be in control of your photography, not the camera. 

It's important to take the camera off auto-ISO and set it to one of the lowest ISO settings available—usually 100. 

To maximise both image quality and your options for creative photography, I recommend that the ISO stays fixed at this low number. 

It's a good idea to place the camera onto a tripod when light levels drop, only raising the ISO when there is no other way to obtain useful images—such as for sport and wildlife photography. You decide when the ISO needs to be raised, not the camera.

 

Shutter speed and lens aperture: the shooting programmes

With the ISO set at a fixed point, the amount of light needed to correctly expose the sensor is pretty much fixed regardless of the lighting conditions. 

You then need a system that controls the amount of light passing from the outside world through the lens and shutter to the sensor. In bright, sunny conditions, this will greatly restrict the amount of light coming through to stop the sensor from being overwhelmed with too much light, while at night, it will do what it can to gather as much light as possible.

That system is the job of the lens aperture and shutter. The former is the variable hole in the lens that controls the light that can pass through at any given moment. 

The shutter is the screen that normally closes the sensor off from the world and opens only for a brief moment whenever the shutter button is pressed. This allows light to pass through the sensor for anything from a fraction of a second to 30 minutes or more. 

The lens aperture and shutter must work together to ensure that the right amount of light gets through to the sensor, and controlling this is the job of the shooting programmes. This system typically comes with a choice of such settings as Auto (or P), S (Tv on Canon cameras), A, M and Bulb. 

The Auto/P mode is a fully automatic system that chooses what it considers to be the right combination of lens aperture and shutter speed for the situation. 

This is fine for simply shooting snaps, but again it puts control of your photography in the camera's hands, not yours. So it's better to use one of the semi-automatic modes, namely A or S/Tv. 

The former stands for 'aperture priority'; in this mode, you can choose the lens aperture, and the camera works out the correct shutter speed. Conversely, S or Tv represents 'shutter priority', meaning that you choose the shutter speed, and the camera works out the corresponding correct lens aperture. 

Each of these semi-automatic modes has separate uses. Shutter priority is important, for example, if you want to ensure that the camera uses a fast enough shutter speed to freeze fast action. Aperture priority comes into its own when the shutter speed is less important but when the depth of field—the amount of an image that is sharply in focus—is critical.

With the M (manual) option, you can choose both shutter speed and lens aperture. This doesn't mean you can choose whatever you want—you must balance the two to ensure that the sensor receives the right amount of light. 

Have the lens aperture too wide open or the shutter speed too slow, for example, and the sensor will receive too much light, resulting in an over-exposed image.

All the above modes usually allow for shutter speeds of up to 30 seconds. What happens if you need a longer exposure? This is where the Bulb mode comes in. 

Setting the camera to Bulb allows you to leave the shutter open as long as you like—up to several hours if necessary. This is one of the few functions in this article that is not quite universal to all digital cameras: many compact cameras do not have this function, though most others do.

 

Understanding and using the histogram

The histogram is a hugely underrated feature that many photographers run away from, frightened by its resemblance to school maths. But it's wonderfully simple to understand and use and is my go-to tool to check with virtually every image whether or not it has been correctly exposed. 

Every image you shoot comes with its own histogram or graph, which you can view on your camera's LCD screen within seconds of pressing the shutter. It can also be seen on your computer monitor once the images have been downloaded. 

It records the range of tonal gradations across the image, i.e. shades of grey (even if the image doesn't appear to contain any grey as such), NOT colours. 

These range along the horizontal axis from completely black on the left, through lightening shades of grey in the middle, to completely white on the right of the graph, representing respectively completely dark shadow areas and brilliantly white highlights, both containing no image detail. The graph's height at any point indicates the proportion of pixels with a particular tonal value.

The histogram is important in determining if an image is well-exposed and should be looked at on the camera's LCD screen every time an image is shot. It is the best way of determining whether an image has been well exposed. Simply looking at the image on the LCD screen is not an accurate assessment. 

The histogram for a well-exposed image stretches across the horizontal axis, indicating a range of tonal values and hence a good contrast range. Still, without spilling into either the black or white ends—nothing in the image is lost in completely black shadow areas or burned-out white highlights. All possible image detail has been captured.

When an image is under-exposed, the histogram will show a spike at the lefthand, black end of the scale. It is said to be 'clipped' at the shadow end, meaning that some of the image has been lost in black shadows and cannot be rescued. 

Conversely, when an image is over-exposed, there will be a spike at the righthand, highlights, and end of the scale. The histogram is clipped in the highlights, with no detail captured in the burned-out whites. 

The image histogram is available in just about all cameras. However, in some models—particularly those aimed at the more basic end—it may be buried deep in the menus and may be quite a trial to find and activate.

Some cameras also come with a 'live' histogram, showing the tonal range of the actual scene before shooting. This is useful as it lets you check for correct exposure before pressing the shutter button. 

 

Exposure compensation

It's quite common to generate an image in which the histogram indicates the image is either under-exposed or over-exposed. In the former, the histogram is too far to the left, while in the latter, it's too far to the right.

In either case, the result is that the affected pixels have captured no image data and so will be blank black in an under-exposed image, or blank white in an over-exposed image, no matter what you do to the image in the computer post-photography. 

This was caused by the camera's exposure meter being fooled into giving an incorrect exposure reading by either some very dark or very bright area in the scene.

This problem can be overcome using the exposure compensation facility, a tool found in all digital cameras. Almost all camera models have a horizontal scale ranging (usually) from -3 to +3, with the default setting in the middle, at zero. 

When set at zero, the camera will shoot the scene using whatever shutter speed and lens aperture combination its exposure meter decides will give the correct exposure. 

The plus and minus numbers refer to the number of 'stops' by which the exposure can be over or under-exposed: +1 means that the image will be over-exposed by one stop, i.e. the amount of light entering the camera will be doubled. -2 means that the image will be under-exposed by two stops; i.e. it will reduce the amount of light entering the camera four-fold. You do not have to over or under-expose by whole stops—the scale does allow for fractions of a stop.

If the camera's exposure meter is inaccurate, resulting in an over- or under-exposed image, you can change the setting on the exposure compensation scale. This usually involves turning a dial on the camera body. 

Suppose an image is over-exposed, resulting in burned-out highlights. In that case, you need to under-expose the image relative to what the camera's exposure meter says the correct exposure should be. 

First, get an exposure reading from the camera's exposure meter and set the exposure compensation scale to a minus figure. This will under-expose the image relative to the camera's exposure meter reading and shift the histogram to the left, reducing the number of pixels burning out. 

Conversely, to over-expose an image that is too dark, take an exposure reading and set the exposure compensation scale to a plus figure. This will shift the histogram to the right, reducing the number of black pixels.

Finally, note that the exposure compensation facility is for use if you're shooting in fully or partially automatic exposure modes. If you're shooting fully manual, you set whatever shutter speed and lens aperture you believe to be correct for the scene being photographed without using the exposure compensation facility.

 

Controlling white balance

For a digital camera to accurately register colours and represent them the same way we see them, it must know what the light source is so it can set a 'white balance'. 

This series of settings ensures that white will always look white to us regardless of the 'colour temperature' of the light source. Once the white setting is correct, all other colours will be rendered accurately.

All digital cameras come with a white balance tool that includes a range of white balance settings appropriate for different light sources, enabling it to read the correct colour temperatures. There is also an auto white balance setting, which automatically detects the light source's colour temperature and sets the white balance accordingly. This is generally accurate for outdoor photography but less for indoor shooting.

Generally, we recommend photographers use the auto white balance setting when shooting outdoors. It saves remembering to change every time the sun goes behind a cloud. 

So, these are the most universally important digital camera tools. Having a firm grasp of how to use these will see any photographer a long way down the road towards using their camera to its fullest potential. 

There are, of course, a few other tools used by many photographers, but some are found only in DSLRs and mirrorless cameras. This is particularly so with focussing points and metering modes. 

The former enables you to select different numbers and combinations of focussing squares within the scene to control what part(s) of the scene the lens will focus on. The latter gives options to meter the light across the whole scene, just a central portion, or simply the very centre. 

While potentially useful, I keep these set by default on a central cluster of focussing points and 'whole scene' (or evaluative) light metering. I rarely move off these for the simple reason that rather than helping with the photography, fiddling with these often wastes time.

Never be distracted from the essentials of the photographic process, but have fun playing with different digital camera settings! 

 

This blog was written by Nigel Hicks, a hugely experienced Devon-based professional photographer. Nigel works with the USA's prestigious National Geographic Image Collection, among many other bodies, and is a Fellow of the British Institute of Professional Photography.

Nigel Hicks runs regular photography workshops in southwest England. To find out more about these go to www.nigelhicks.com/photography-workshops-courses/.

To find out more about Nigel's work, feel free to take a tour of the website at www.nigelhicks.com.

 

Specialist camera insurance from Ripe Photography

If you're heading out to master these essential digital camera features, you may also want to protect your camera and accessories through specialist camera insurance.

At Ripe, we arrange bespoke cover that can be tailored to fit your exact requirements, so you only pay for what you need.

Click here to learn more about specialist camera insurance, or hit the button below to get an online quote today.