Understanding the functions of a digital SLR camera

Understanding the functions of a digital SLR camera
Your digital SLR camera may contain many functions and settings beyond comprehension. This handy guide helps you to get to grips with your camera.

Using the shoot mode

Auto (A, or A+)

Rather than a one-mode-fits-all option like a disposable camera, the auto function on you camera will determine the adjustments for each individual exposure, including adjustments to both the aperture and shutter speed. But your camera doesn’t always know best, particularly when it comes to your more, erm ‘creative’ ideas, so it’s best to explore its settings. 

Aperture (A)

DSLR shoot mode: Aperture
Your camera’s dial indicates a semi-automatic mode (A); you’re in control of the aperture and your camera determines the shutter speed.
The aperture simply means the size of the opening through which light comes enters the lens—a bit like when your pupils dilate and contract.
Measured in f-stops, the size of the opening is equal to the amount of light, so if you’re shooting outside on a bright sunny day, then your f-stop might be better set to a high number such as f/8.0. This will produce a smaller hole, letting less light in. If shooting in dim conditions, or if you simply want your camera to pick up as much fine detail as possible, then the aperture is best left on a lower number such as f/2.8, allowing more light into the lens.

Shutterspeed (S)

DSLR Shoot mode: Shutterspeed
This works the other way around. You’re in control of the shutter speed and the camera will determine the aperture.
To capture your friend’s best dance moves you should set the shutter speed to the tiniest fraction of a second. This way your frined won't be all blurry. 
On the other hand, a photo of a busy London street taken with a shutter speed of six seconds would show the blurred lines of movement along the roads and pavements, but it would also capture the architecture in fine detail as you’re letting much more light into the lens.

Programme (P)

DSLR Shooting Mode: Programme
With the programme function you are able to go into your camera’s menu and set the aperture and/or shutter speed so that your camera will adjust to one or the other automatically. This saves you manually changing the dial on your camera between S and A everytime.
This is particularly useful if you’re going to be shooting over a long period of time with changing subject matter, less fiddling and more memories!

Manual (M)

DSLR Shooting mode: Manual
Fully manual mode is typically indicated by M on your camera’s dial.
Shooting in this mode means you have 100% control over both the shutter speed and the aperture setting.
An indicator, called a light metre, on your camera’s screen or inside the view finder will tell how under or exposed the image will be, but it’s up to your to make the adjustments. 
Light metre
You’ll be surprised how quickly you can build up to fully manual once you have mastered the above setting. Don’t be afraid, there is no waste with digital!

Sensitivity to light


Understanding SLR: ISO mode
With old fashioned cameras, rolls of film come in a selection of different ISOs. This specifyies the film’s sensitivity to light.
ISO 100 is a low sensitivity to light, which means that more light is needed to achieve a particular exposure and ISO 6400 on the other hand would handle a super bright day with sun glinting off the water.
To understand ISO rates in digital photography however, you could swap the word ‘film’ for ‘sensor’.
A high ISO setting on your DSLR means that the sensor will work at an increased sensitivity to light, allowing you to snap moody images at dusk for example.
Generally keep ISO at around 200, if you head indoors take it up to around 600.
You may understand by now that your ISO settings can work in tandem with your aperture and shutter speed settings—so keep that in mind when you go fully manual!

Metered exposure

Metered Exposure
Your DSLR constantly makes assessments of lighting conditions, exposing any image with an average of 18% grey, which is why snow scenes can seem strangely dark.
To help adjust the assessment criteria, there is usually a little button by the shutter that looks like a +/- in a black and white square. You can press this during shooting in dark or bright scenes to let your camera know it should be adjusting to less or more than 18% grey.

Getting it in focus

The two main focus modes are single and continuous.

Autofocus single (AF-S)

This is used best for stationary subjects. Point your camera at your still person or object, half press the shutter button to focus and then fully press to take the photo.

Autofocus continuous (AF-C)

is a good setting when working with movement. Again, half pressing the shutter button with lock a focus onto your moving subject but in this mode the camera will continue to adjust the focus as you subject moves about until you fully press the shutter button.
For more advanced options, check your camera’s manual.

Adjusting white balance

Every now and then a photo will have blue or yellow hue. This is caused by your camera’s white balance.
Your camera will make an assessment of different light sources and it will generate its balance of ‘white’ from different waveforms. Our eyes and brains can account for changes between electric and daylight, meaning a white surface will always look white to us, but the camera needs a bit of help here.
In your camera’s menu there will be a option to set white balance that is divided by light type:
  • Daylight is for a clear and sunny day 
  • Cloudy warms natural light in an overcast situation 
  • Shade setting accounts for a natural blue hue and warms up the image accordingly
  • Tungsten will be used for indoor settings and electric light to cool down yellow tones 
  • Fluorescent setting is great for balancing out strip lighting’s green and blue tones
  • The flash setting will add a blue tinge to your images so use with caution
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