Wednesday/Thursday Nov 17th / 18th Lens Aperture Wednesday/Thursday Nov 17th / 18th

Lens Aperture Your lens aperture is an important control for dimming or brightening images, or helping to compensate for bright or dim subject conditions. There is an even more important effect on visual results whenever you photograph scenes containing a number of items at various distances from the lens.

Lens Aperture More light Less Light

Lens Aperture Most smaller-format cameras control the aperture size automatically, and some SLR cameras you may have to change this manually, depending on the camera. The F-number system, which is an internationally agreed sequence, means that every lens set to the same number gives the same brightness, regardless of what type of camera you are using.

F-Numbers This system works because each f-number take into account 2 main factors which control how bright an image is formed: Distance between lens and image – you can control this Diameter of the light beam – this depends on your camera setting

F-Numbers Most smaller format cameras stop down to f/16 or f/22. Larger cameras are designed to continue down to f/32 or f/45 What do I mean by “stop down”? Smaller apertures are useful for extra depth of field, but will start to destroy image detail if taken down too much.

Depth of Field Depth of field is the distance between the nearest and furthest parts of a subject that can be images with acceptable sharp detail at one focus setting of the lens.

Depth of Field Imagine, for example, that the shot consists of a head-and-shoulders portrait with a street background behind and some railings in front What, specifically, will you focus on with your lens?

Lens Aperture If you focus the lens to give a sharp image of the face and take a photograph at the widest aperture (on a manual lens), both the street and railings will appear unsharp. Widest aperture (smallest f-number) gives the least depth of field Smallest aperture (highest f-number) gives the most depth of field.

Higher f-number Lower F-number

Depth of Field There are 2 other significant effects: Depth of field becomes less when you are shooting close-ups and greater when all your subject matter is further away. The longer the focal length of your lens, the less depth of field it gives, even with the same aperture and subject distance. PRACTICE using your peers as subjects, making sure you have something in the background and foreground. What happens?

Depth of Field

Depth of Field It is very important to be able to control the depth of field and make it work for your pictures, not against them. By choosing shallow depth of field (close-up) you can isolate one item from others at different distances. You can create emphasis on certain objects.

Depth of Field

Depth of Field

Shooting Assignment Practice taking photos using depth of field. In the classroom In the building Picnic Area Outside Check in: 10:20 – 10:40 – 11:00 –