The light generated, transmitted and reflected by the objects in our surroundings allows the human eye to view, record and interpret the world around us as images.
It is worthwhile distinguishing between the following concepts
- Looking - arranging what you can see
- Seeing- receiving light energy and converting it into nerve impulses
- Observing- the analysis, interpretation and classification of nerve impulses in terms of objects or effects
The Sun:
The sun has the most prominent impact on natural lighting, powerful enough to completely alter the appearance of any image. The sun rising and setting sees a change of light very visibly, including a immense shift in colour.
Both when rising in the morning and setting in the evening, the sun produces long shadows, whereas in between times, peaking in the middle of the day, it produces short shadows.
In the middle of the day, the sun can be referred to as "white" light as it represents the most even mixture of all colours from the spectrum. This could be described as "colourless" and in the middle of the day.
Below is an example of the Empire State building, New York showcasing how the varying sunlight at different points in the day can alter the feel and colour of an image.
The colour of an image can be altered significantly depending on the time of day. The main points in the day when the sun greatly affects the colour of the image are, predawn, morning, mid day and twilight. Below are images of The Eiffel Tower, Paris in that order, showcasing the differences.
The predawn photo shows a dark blue sky with red tinges, as the sun is yet to rise. The Eiffel Tower itself is very dark at this point in the day, outputting little or no brightness at this time of the day.
The morning image is transformed completely with the brightness of the morning sun altering many effects. The red tinges in the sky have become brighter, more yellow, in the process. The sun shining on the tower itself outputs a far more vibrant colour, with increased light and brightness. In turn, the increase in light makes the formation and the features of the tower far more visible.
The midday image shows the image in its most natural light. This is down to, as previously mentioned the insertion of "white" light, the most even represenation of the colour spectrum. Although it shows The Eiffel Tower in its most natural state, the reduction in light shining down on the tower in comparison to dawn means, the detail in the architecture is slightly less.
The twilight image shows a darker, dim display of The Eiffel Tower. In parts you can see the reduced detail in the architecture, but for the most part it is artificially lit up, which limits the analysis of natural light effects. As the sun is setting, the red hinges, visible in the predawn image, are beginning to return. The blue colour from the daylight is beginning to darken without the influence of the sun.
Clouds in the sky soften and diffuse light, spreading it more evenly, although the light coming from the sun on a cloudy day may appear white to the human eye. The diffusion of light is a very useful method and can often be used as it helps correctly emphasise the intended object of the picture. An example of where the diffusion of light is commonly used would be a portrait.
Below is an example of light diffusion in a potrait:
The play of light in images is down to three factors:
Contrast:
An image which has the attributes of being high-contrast would be likely to be one taken in increased sunlight. The intensity of the sunlight is responsible for producing sharp and highly visible details and effects such as saturated colours.
Low-contrast images are the opposite. They are more likely to appear in overcast situations as I previously touched on the fact that clouds diffuse (or scatter) light, making the colour in images appear more balanced, evenly distributed and less bright. This is due the gradual blending of tones, this reduces the shocking vibe that may be more present in high-contrast images.
High contrast images can be useful in times where a particular emphasis is required on an object which has been subjected to the light. Low contrast images are more useful in situations where you are looking to capture detail in an image, where it may not be as visible in high contrast situations.
Colour:
Colour film has a higher sensitivity than the eye and can produce unwanted tints to images taken in a certain light, such as green on fluorescent lighting and orange on daylight. Image processing can help overcome this and modifications by the user can achieve the view of the picture they had hoped for.
The human eye is attracted to colours, particularly bright colours. Colours used in images can often depict the mood of a picture and the author may use this to his advantage. Instinctively, humans attribute certain colours to certain feelings and attributes and using colours effectively may help an image be appreciated by its intended audience in the correct way.
Standard characteristics of colours:
Yellow:
- Direction
- Contrast
- Colour
Direction:
The direction that the light is striking an image is vital, there are three types of image illumination which are:
- Front-lighting
- Side-lighting
- Back-lighting
If you are observing an image and a source from behind you shines directly onto the object, this is termed as front lighting. Side lighting is the creation of strong shadows to emphasise texture, making the image more defined, in elements such as shape dimension and depth. As the name suggests, back-lighting is the opposite of front-lighting, with a source behind the object of image creating lights and other effects.
Contrast:
An image which has the attributes of being high-contrast would be likely to be one taken in increased sunlight. The intensity of the sunlight is responsible for producing sharp and highly visible details and effects such as saturated colours.
Low-contrast images are the opposite. They are more likely to appear in overcast situations as I previously touched on the fact that clouds diffuse (or scatter) light, making the colour in images appear more balanced, evenly distributed and less bright. This is due the gradual blending of tones, this reduces the shocking vibe that may be more present in high-contrast images.
High contrast images can be useful in times where a particular emphasis is required on an object which has been subjected to the light. Low contrast images are more useful in situations where you are looking to capture detail in an image, where it may not be as visible in high contrast situations.
Colour:
Colour film has a higher sensitivity than the eye and can produce unwanted tints to images taken in a certain light, such as green on fluorescent lighting and orange on daylight. Image processing can help overcome this and modifications by the user can achieve the view of the picture they had hoped for.
The human eye is attracted to colours, particularly bright colours. Colours used in images can often depict the mood of a picture and the author may use this to his advantage. Instinctively, humans attribute certain colours to certain feelings and attributes and using colours effectively may help an image be appreciated by its intended audience in the correct way.
Standard characteristics of colours:
Yellow:
- Bright
- Cheerful
Red
- Exciting
- Warm
Green and Brown
- Calm
- Restful
- Natural
Blue
- Very much varying on shade, can be contrasting or subdued.
Modifying light in images can give you a better foothold on how you intend to express an image. Modifications of colour, contrast and brightness can give an image an effect that was intended or possible in its original state.
No comments:
Post a Comment