Category Archives: 02. Focus

Focus at different apertures

This exercise aims to demonstrate the way that aperture can affect the focus in a shot. For this exercise I chose to photograph coloured pencils from a very low angle. I set the camera on a tripod and focused on the orange pencil in the centre of the image.

18mm, F3.5, ISO 800

I set the camera to Aperture priority, allowing the shutter speed to be automatically selected by the camera, and  took the first picture.  I set the lens to it’s widest available aperture, F3.5.

18mm, F11, ISO 800

I took the second photograph with the lens set to F11.

18mm, F22, ISO 800

The photograph was taken with a small aperture of F22.

I then printed the photographs and compared them. There was a noted difference in the limits of sharpness between each.

In image 1  the yellow, red and orange pencils are the only items which are sharp, with the pencils further back becoming increasingly blurred.

In photograph 2 the limits of sharpness become a little wider. The first 6 pencils are sharply focused with even the text printed on the navy blue pencil becoming clearer.

The third photograph has an even wider area of sharpness with more detail becoming noticeable such as the grain in the wood of the table and the text printed in the rear pencils.

I found the difference between these 3 images quite remarkable. I personally liked photograph 1 the most. I liked the blurring of the pencils and colours at the end of the row as it conveyed a sense of distance.

Advertisements

Focus with a set aperture

This activity looks at focus. It requires me to select a scene which has depth of field and then, with the camera set to it’s lowest f-stop, take 2-3 photographs while focusing on different points in the distance within the shot.

I selected a park scene, looking across some shrubbery and trees.

1.DSC_0024

55mm F5.6 ISO 100

In photograph 1 I placed the focus at a point a 1/4 of the way in from the left. This has put the plants in the foreground of the shot in focus, allowing the details in the leaves to be clear and the plant stems to be well defined. The trees and plants to the right and in at the back of the image are blurred.

2.

DSC_0028

In this second photograph I focused on the centre of the image. This has allowed the centre stem to become a focal point. This draws the eye to the fine detailing in the leaves and their translucent qualities. There is still a feeling of distance to the shot as the trees and fencing to the rear are blurred.

3.

DSC_0026

55mm F5.6 ISO100

For the third photograph I aimed the focus 3/4 of the way across from the left. This brought the tree more into focus and caused the plants at the forefront to become blurred.

This exercise has shown how the focal point in an image can draw the viewers eye and how a sharp object can really stand out against an out-of-focus background.

While there appears to only a little difference between images 1 and 2 I prefer image 2. My eye was drawn immediately to the almost centre stem of leaves. The central focal point here allowed the detail to be sharp against the out-of-focus surroundings. The image also retained it’s sense of depth.

I decided to repeat this exercise, this time using a more man-made subject, a wardrobe full of clothes. I chose this subject as the colours and patterns made the focal points easier to see.

1.focus right, 26mm, F4.2, ISO200mm

26mm, F4.2, ISO 200

In this image I placed the focal point to the far right of the shot which shows the garments hanging here clearly. The eye is drawn in particular to the blue and white striped shirt which is sharply in focus.

2.

focus centre, 26mm, F4.2, ISO 200

26mm, F4.2, ISO 200

The central focal point in this shot shows the brown and white stripes shirt very clearly against the out-of-foucussed garments in the forefront and background.

3.

focus left, 26mm, F4.2, ISO 20026mm, F4.2, ISO 200

The left focal point sharpens the view of the formal shirts hanging to the rear of the image. This allows the thin stripes on the sleeves to become clear for the first time.

This exercise has shown me the value in varying focal point within an image and the way in which a sharp image can really stand out amidst out-of-focus surroundings.