05-02-2025, 05:03 PM
Time exposure The ‘B’ (Bulb) setting:
This can be found by winding your shutter speed down to beyond the 30” (seconds) (or dedicated dial such as with a Canon 7D) where the next step is usually the ‘Bulb’ time setting which enables you to keep the shutter open for any desired period, from 30” to many minutes or many hours.
This setting can be used for night shots, where you can allow the film/sensor to soak up the moonlight lighting a landscape or record the streaking lights of moving traffic, star trails perhaps or long firework displays, if a black card is used to cover the lens between the fireworks going off so as not to record unwanted light.
Note: for ‘B’ setting shots, or really any shot longer than approx 1/30th sec, the camera must be held firmly or mounted on a tripod because any unwanted movement could ruin the shot. Perhaps a beanbag on a fence post is all you have, its ok, as long as the camera remains steady throughout the exposure.
Colour temperature:
The computation of our eye to brain view is amazing, if we see a white object we know to be white, our eye sees it and our brain computes to confirm this, whether the white object is bathed in an orange colour cast from the light of a candle or the harsh bright glare cast from strong sunlight reflecting from snow on the white object, our brains tells us this in an instant.
However, despite how clever our cameras are, unfortunately they are unable to make these calculations of colour balance without our guidance and input. See the section on WB (white balance) below, and check your camera’s manual for further study on this.
To start you off, the WB auto setting will be helpful.
Custom balance is where it’s really at though for geek or professional alike and this you can pick up quite quickly.
But of course, should a particular colour cast appeal to you, then that is a correct exposure.
Photography is about being able to express your personal creativity through the lens and if it is your desire to take your picture creating mood by under exposing or colour tint through use of white balance settings, then that can be considered a correct exposure. Photography is all subjective.
EV Exposure value:
A combination of shutter speed, aperture and ISO. In photography, exposure value (EV) denotes all the combinations of a camera's shutter speed, relative aperture and available ISO range that in combination give the same exposure (a technically correct exposure). Exposure values are given as a numeric, from EV-3 to EV+18, where EV16 represents a bright sunny day and EV2 represents the available light slightly after sunset.
For each exposure value there are at least 6 possible shutter, aperture and ISO combinations that will all give a correct exposure.
The light meter in your camera will help you with this and as we have discussed, this built in gadget is at the heart of the photographic triangle.
On most cameras, there is no direct way to transfer/convert an Exposure Value in to camera settings; however, the end result is that exposure refers to how bright or dark your photograph is due to the amount of light that is recorded by your cameras film/sensor.
A properly exposed photograph should (normally) resemble the brightness of the original scene. A poorly exposed photo will either be too dark or too bright and may contain areas that are so dark or bright that they contain no detail at all.
So how can we control the exposure of a photograph?
That is where the exposure meter and triangle come into play.
EV Compensation:
Many current cameras allow for exposure compensation, and usually state it in terms of ‘stops’, where one stop of either the f-stops or the stops of shutter speed equals 1x EV (+or-).
This will, with experience be determined by whether you wish to meter the highlights or the shadows which in turn will affect the form of the final image. In this context, ‘EV compensation’ refers to the difference between the indicated meter settings and the adjustments you set for your particular brand of exposure. For example, an exposure compensation of +1 EV (or +1 stop) means to increase exposure, by using either a longer exposure time (shutter speed) or a smaller f-number (wider aperture). Simply view your scene through the view finder with the shutter trigger depressed half way and make your compensation adjustments + or – upto 2 whole stops or parts thereof.
WB White Balance:
The adjustment to keep neutrals, neutral, is called white balance in the simplest terms. So that white looks white in the finished result.
Colour casts and image imperfections are caused when the temperature of the light for a given scene does not correspond with the temperature range set in the camera.
Try to imagine heating a piece of steel bar; soon after the heat source is applied, the bar starts to warm as the heat builds up, causing the temperature to rise.
Soon the bar begins to glow from the heat, firstly a light warm glow, similar to the light given off by a burning candle (approx 2000k) (Kelvin)).
As the heat intensifies, the glow turns to a much fiercer yellow/orange, similar to the glow of a 60Watt light bulb (approx 3500k). As the heat intensifies further still, the glow becomes brighter, similar to a 500Watt floodlight (approx 7000k), until just before the molecular structure breaks down completely and the bar melts into a blob, it glows so bright, like the sun, sometimes referred to as ‘white heat’, where the colour temperature is said to be approx 10/11000k.
So, if you're taking a picture on a bright sunny day and the white balance setting in the camera is set to capture an image under candle light, the image will be cast cold blue and vice versa.
For a pleasing image, set the white balance to suit the conditions. This can be done by using any of the pre-settings or setting a more accurate ‘custom white balance’, and instruction on this for your particular camera will be found in your camera instruction manual.
This can be found by winding your shutter speed down to beyond the 30” (seconds) (or dedicated dial such as with a Canon 7D) where the next step is usually the ‘Bulb’ time setting which enables you to keep the shutter open for any desired period, from 30” to many minutes or many hours.
This setting can be used for night shots, where you can allow the film/sensor to soak up the moonlight lighting a landscape or record the streaking lights of moving traffic, star trails perhaps or long firework displays, if a black card is used to cover the lens between the fireworks going off so as not to record unwanted light.
Note: for ‘B’ setting shots, or really any shot longer than approx 1/30th sec, the camera must be held firmly or mounted on a tripod because any unwanted movement could ruin the shot. Perhaps a beanbag on a fence post is all you have, its ok, as long as the camera remains steady throughout the exposure.
Colour temperature:
The computation of our eye to brain view is amazing, if we see a white object we know to be white, our eye sees it and our brain computes to confirm this, whether the white object is bathed in an orange colour cast from the light of a candle or the harsh bright glare cast from strong sunlight reflecting from snow on the white object, our brains tells us this in an instant.
However, despite how clever our cameras are, unfortunately they are unable to make these calculations of colour balance without our guidance and input. See the section on WB (white balance) below, and check your camera’s manual for further study on this.
To start you off, the WB auto setting will be helpful.
Custom balance is where it’s really at though for geek or professional alike and this you can pick up quite quickly.
But of course, should a particular colour cast appeal to you, then that is a correct exposure.
Photography is about being able to express your personal creativity through the lens and if it is your desire to take your picture creating mood by under exposing or colour tint through use of white balance settings, then that can be considered a correct exposure. Photography is all subjective.
EV Exposure value:
A combination of shutter speed, aperture and ISO. In photography, exposure value (EV) denotes all the combinations of a camera's shutter speed, relative aperture and available ISO range that in combination give the same exposure (a technically correct exposure). Exposure values are given as a numeric, from EV-3 to EV+18, where EV16 represents a bright sunny day and EV2 represents the available light slightly after sunset.
For each exposure value there are at least 6 possible shutter, aperture and ISO combinations that will all give a correct exposure.
The light meter in your camera will help you with this and as we have discussed, this built in gadget is at the heart of the photographic triangle.
On most cameras, there is no direct way to transfer/convert an Exposure Value in to camera settings; however, the end result is that exposure refers to how bright or dark your photograph is due to the amount of light that is recorded by your cameras film/sensor.
A properly exposed photograph should (normally) resemble the brightness of the original scene. A poorly exposed photo will either be too dark or too bright and may contain areas that are so dark or bright that they contain no detail at all.
So how can we control the exposure of a photograph?
That is where the exposure meter and triangle come into play.
EV Compensation:
Many current cameras allow for exposure compensation, and usually state it in terms of ‘stops’, where one stop of either the f-stops or the stops of shutter speed equals 1x EV (+or-).
This will, with experience be determined by whether you wish to meter the highlights or the shadows which in turn will affect the form of the final image. In this context, ‘EV compensation’ refers to the difference between the indicated meter settings and the adjustments you set for your particular brand of exposure. For example, an exposure compensation of +1 EV (or +1 stop) means to increase exposure, by using either a longer exposure time (shutter speed) or a smaller f-number (wider aperture). Simply view your scene through the view finder with the shutter trigger depressed half way and make your compensation adjustments + or – upto 2 whole stops or parts thereof.
WB White Balance:
The adjustment to keep neutrals, neutral, is called white balance in the simplest terms. So that white looks white in the finished result.
Colour casts and image imperfections are caused when the temperature of the light for a given scene does not correspond with the temperature range set in the camera.
Try to imagine heating a piece of steel bar; soon after the heat source is applied, the bar starts to warm as the heat builds up, causing the temperature to rise.
Soon the bar begins to glow from the heat, firstly a light warm glow, similar to the light given off by a burning candle (approx 2000k) (Kelvin)).
As the heat intensifies, the glow turns to a much fiercer yellow/orange, similar to the glow of a 60Watt light bulb (approx 3500k). As the heat intensifies further still, the glow becomes brighter, similar to a 500Watt floodlight (approx 7000k), until just before the molecular structure breaks down completely and the bar melts into a blob, it glows so bright, like the sun, sometimes referred to as ‘white heat’, where the colour temperature is said to be approx 10/11000k.
So, if you're taking a picture on a bright sunny day and the white balance setting in the camera is set to capture an image under candle light, the image will be cast cold blue and vice versa.
For a pleasing image, set the white balance to suit the conditions. This can be done by using any of the pre-settings or setting a more accurate ‘custom white balance’, and instruction on this for your particular camera will be found in your camera instruction manual.