Part 2 is dealing with Imaginative spaces, and in these exercises I have been asked to work in Aperture Priority. This is normally found on the dial at the top of the camera. Sometimes it comes as just an A or Av depending on the make of the camera. I will be using a canon which has the Aperture priority setting as Av.
As usual I will go on to explain how different settings will affect the outcome. Have in mind a concept of what image you want to end up with then set the camera accordingly. Here we will be talking about lens and depth of field, but before the exercises are carried out, its important to get a basic understand of what the settings mean and how they affect the shot……
Using the aperture priority setting will allow me to change the ISO and shutter speed, whilst keeping the Av at a constant but the Shutter Speed and ISO will change to compensate in most modern digital cameras to maintain the exposure. The Av setting will have a direct effect on the Depth of Field (DoF), Shallow depth of field is usually when the subject is in focus and the rest of the image is blurry, this could be in front of the subject or behind, as in the images below
In the image on the left, I wanted to show the blossom on my apple tree, but the background would have been a distraction, so I wanted it to be blurry. This is shallow DoF, where flower is sharp. Deep DoF is where more of the whole image is sharper. One case where you would not want to show any depth of field is when taking photographs of landscapes as you will want all the image in sharp focus.
More on Dof further on in this exercise
The 3 main elements that will need a little thought in producing a sharp clear image or shallow DoF are, ISO, Shutter and Speed setting. These are collectively known as the ‘exposure triangle’
In the earliest cameras, there was no facility to change the aperture. The aperture controls the amount of light that enters the camera, and in the early days there was no way to fix something over the lens to reduce the amount of light exposed. The aperture is the opening in the lens. It may have taken hours to expose an image. One development that did help to reduce the exposure time was the introduction of light sensitive paper, reducing the exposure time needed to seconds rather than hours.
With todays digital cameras, when the shutter is pressed, a controlled amount of light is allowed to enter the camera, hitting the image sensor. The larger the hole, the more light is allowed in, and the brighter the image will be. The smaller the aperture (hole), the less light enters, resulting in a darker image.
The size of the aperture is normally referred to as the F Stop. For example you may have on your camera the following;
f/2 f/4 f/5.6 f/8 f/22
Changing the F Stop setting, can be confusing to the new photographer as the smaller the number, (ie F/2) means you are actually making the hole (aperture) bigger, letting in more light.
When taking night shots or in poor light, a ‘lower’ setting is required to allow more light in, making the aperture larger, while taking shots on a bright sunny day, will require less light to enter, therefore the aperture should be smaller.
In the two images above, the first was taken of the Albert Dock Liiverpool, I wanted to capture the orange glow of the buildings as well as the blue colour of the water. It was a dark night and if I had used automatic setting, the flash would have come into play. The result would have been a bright foreground and the building/water would have lost the colour and been very dark. So the settings had to reflect the circumstances.
The second picture, on the right was taken in Turkey on a hot, bright summers day, in mid afternoon. The natural light meant that if I had taken the photo on automatic there would not really have been much difference, except that the result may have been a little more on the blue side that I would have wanted
aperture size = f stop = f/3.5
shutter speed = exposure time = 2 sec
ISO = sensitivity = 100
aperture size = f stop = f/5
shutter speed = exposure time = 1/250 sec
ISO = sensitivity = 125
Changing the aperture setting is one element that will have a direct effect on the depth of field, (DoF). As previously discussed, Depth of field relates to areas which are in focus and which are not. At times, the subject in the foreground of the image, is what the photographer wants to emphasis, cutting out the clutter or distraction in the background, or maybe to give the illusion of distance. With this in mind, the photographer will want the foreground sharp, and the background blurred.
Besides aperture setting, focus also plays a part in how much of the image is sharp, as does the focal length. DoF is referred to as shallow or deep. Shallow depth of field means that there is only a small part of the image that is sharp, while deep DoF refers to a larger part of the image that is in focus. Using a wider aperture will result is shallower DoF
large aperture=small F number=shallow depth of field
Small aperture=large F number=deeper depth of field
So to decrease DoF, use a wide aperture, (small F number), move closer to the subject, and increase the focal length. I increase DoF, use a smaller aperture (large F number), move further from the subject and shorten the focal length
Focal Length 20mm
Focal Length 20mm
The depth of field in the first photograph above, taken at Rhaeadr Falls in Wales has a shallow DoF, so that the buds on the tree are quite sharpe, with the falls and the person on the bridge in the background blurred. Whereas in the next image, the depth of DoF is deep, leaving most of the image in focus. The only thing that was changed was the ISO. It was a dull cloudy day and the light was not very good, so the settings had to reflect the circumstances.
focal Length 24mm
focal length 105mm
In the two images above, taken at Market Drayton medieval fayre, the birds on display were situated in a corner of the town with unsuitable background for the final image I wanted to portray. I needed to blur the background, and get a better shot of the head, as the jesops that the bird was wearing on its feet were something I did not want in the shot. I wanted the shot to look like it had been taken in the wild.
The buddleia in the photograph to the left attracts numerous butterflies in the summer months. This particular plant is in my back garden. The butterfly I was trying to photograph kept landing on a the buds with a chimney and TV aerial in the background. This background was not what I really wanted, and for the most part it is blurred, although I think I should have blurred it more, to become a non-entity and stop being a distraction. Additionally, the same applies for the image of the bee on the clover flower. By blurring the backgrounds further, the subject would increase in prominence.
More examples of varying DoF can be found below
The Shutter Speed
The shutter speed is like a curtain that opens and closes over the aperture. This is the amount of time that the open aperture is actually exposed to the light. Shutter speed is measured in seconds.
The shutter speed will affect the image and determine if the effect is a moment frozen in time, or blurred, showing movement. When set on a ‘slow’ shutter speed, ie ‘open longer’, the image will show movement by producing a blurred image. This effect is desirable when taking shots of waterfalls or fast moving sports events such as motorbike racing. In a waterfall shot the water will show a blurred movement of the water, while the surrounding area is in focus. As with an image of a fast paced motorbike race, the wheels on the motorbike will show up as blurred, depicting a sense of movement.
nose past the post
In the image to the left, taken at Marsa Races in Malta, movement can be seen in the wheels and the dusts thrown up by the horses hooves. The DoF slightly blurs the background, but the horses and jockey are pretty sharp.
f/3.9 1/360sec ISO800 Focal Length 41mm
The shutter speed is measured in fractions of a second, ie 1/4 means that the curtain is open for a quarter of a second, while 1/250 is two-hundred and fiftieth of a second. Again as in basic fractions, the smaller the ‘number’ will mean that the curtain will be open longer.
The simplest way to explain this is that 1/2 is larger than a 1/4, therefore 1/500th will freeze the action and produce a sharper in focus picture.
lance the target
At Rinella Museum in Malta, the re-enactment was a great photo opportunity to try and get some images that illustrate movement. It would have been better if the horses front legs were slightly off the ground and the only bit if the image that illustrates movement are the back legs and dust. Other than that, the image captured is quite static.
f/5.6 1/400sec ISO80 focal length 29mm
The International Standards Organisation (ISO) is the governing body that provides standards in many areas, including film speed, (sensitivity). By film speed we mean that sensitivity to light that the film has. Depending on the ISO setting of the film, will reflect on the sensitivity it has to light, and the amount of information recorded.
lower number=slower film=need more light=longer exposure
higher number=faster film=need less light=shorter exposure
Fast film will record less detail of an image, therefore resulting is a grainy looking image. This grain is known as ‘noise’. While slower film will record more detail, making the image much sharper.
Other elements required to produce a sharp, clear image, will also be affected by film speed, such as contrast, brightness and black and white areas.
With the development of the digital camera, film has almost become obsolete. Film has been replaced with the digital image, and ISO settings relates to the number of pixels that are recorded. Its worth mentioning at this point that a RAW setting will capture more pixels than a jpeg, which means that there will be more detail available to process. The is a down side, these files are big and you may have problems uploading to the internet. This is why I always use jpegs for my blog and only upload a few processed raw files. R>A>W is not an abbreviation for anything, what you see is what you get, the files are raw and have not yet been processed. Most of todays cameras cannot show a raw file and unless processed viewing them on a windows PC or smart phone is almost imposable.
Now that all out of the way lets get on with the exercise……
I spent the day at Houghmond Abbey near Shrewsbury as the exercise stated that scenes that had depth would be required. I had some problems as I couldn’t get a picture with enough depth. I did do the excersce again at home, along the hallway and outside, down the side of the bungalow, with better results. It was a bright sunny day at Houghmond , which I don’t particularly like it as it plays havoc with shadow and light. But never the less at least it wasn’t raining…..
Although I took photographs in both RAW and Jpeg, the images below are all jpeg, as taken with no manipulation. RAW files will be processed and added at the end of the section.
Setting the camera at Av take a sequence of 5 or 6 shots at different focal lengths (zooming in/out) and get a feeling of how the angle of view corresponds to the different focal lengths without moving back and forth from the subject. Which shot in the sequence feels closest the the angle of view of your normal vision?
The images below are what I thought would be good for this exercise, but I was wrong, because the scene was not deep enough… hmm
These examples below are not very good as there is furniture in the way
On reviewing the images and to answer the 2 questions for this exercise, I suppose the one in this sequence that feels closet to the angle of view of my normal vision is one at the end, because there seems to be less distortion, unlike the ones at the beginning, the path does not seem to be going uphill. Also the rain water drain pipe in the first image is distorted. Does zooming in from a fixed view point change the appearance of things? Yes it does. It changes the perspective, so in order to combat this I would have to change my viewpoint.
Read more on perspective and flat photography at the links below