Relationship between SLR Camera Structure and Lens

Photography Masterclass

Photography Masterclass Online Course

Get Instant Access

Figure-1

1. Check the subject through the viewfinder.

2. The mirror rises and the shutter opens to expose the 3. The shutter closes and the mirror returns to its original film/imano conenr __nncitinn

1. Check the subject through the viewfinder.

2. The mirror rises and the shutter opens to expose the 3. The shutter closes and the mirror returns to its original film/imano conenr __nncitinn

Camera Structure

Photograph plane

2nd principle point

Photograph plane

2nd principle point

What does the world look like through a lens? Construction and characteristics of the SLR camera.

The single-lens reflex (SLR) camera construction makes it possible to use a wide variety of interchangeable lenses to build the optimum system for photography. This is the attraction of the SLR camera. The major characteristic of this camera is the viewfinder system. Because the image that actually reaches the focal plane is displayed in the viewfinder, the image that will be captured digitally or on film can be checked in advance.

The light rays that pass through the lens are deflected upward by a mirror in front of the lens to show the image in a focusing screen that is equidistant with the focal plane. A pentaprism is then used to correctly orient and project the image before it is seen through the eyepiece. When the shutter button is pressed, the mirror rises up and the shutter opens to expose the film or image sensor. When the shutter closes, the mirror returns to its original position (Figure-1). This makes it possible to accurately frame images without being affected by parallax, a problem with compact cameras, which have different light paths for the shooting lens and the viewfinder.

How different focal lengths can change your shots.

The impression given by a photograph can be greatly changed by using a variety of different lenses for different purposes. In particular, differences in lens focal length greatly change the range (angle of view), perspective, and depth of field of the

Photo 1

Photographed using an EF 28-135mm f/3.5-5.6 IS USM

Figure-3

Focal length

Photo 1

Photographed using an EF 28-135mm f/3.5-5.6 IS USM

Figure-3

Focal length

Slr Camera Strcture
135mm

subject being photographed.

The angle of view is expressed as the angle of the range being photographed, so it is generally shown as the angle of the diagonal direction. Naturally, the image captured by the lens is circular—not a rectangle the size of the focal plane—and this image is called an "image circle." The image that is actually photographed is taken from the center of the image circle (Figure-2).

In the case of a 35mm camera, the angle of view (diagonal view angle) is 180° using a 15mm fisheye lens, 46° using a 50mm lens, 24° for a 100mm lens, 12° for a 200mm lens, and about 4° for a 600mm telephoto lens, so the longer the focal length, the narrower the angle of view (Figure-3). The angle of view becomes approximately 1/2 when the focal length is x2

and the photographed area becomes 1/4. Photo 1 shows photographs taken using 28mm, 50mm, and 135mm focal lengths. The composition changes dramatically from a wide view showing the table and surrounding area to a close-up of the subject.

Screen change in accordance with focal length

Slr Structure

Understanding focal length allows you to select the appropriate lens.

This series of photographs shows how lenses with different focal lengths photograph the same location.

The shorter the focal length of the lens, the wider the scene coverage, and the longer the focal length, the narrower the scene coverage. As was mentioned on the previous page, when the focal length is 2x, the area of the photographed image is 1/4, so it is useful to remember the degree of change, especially for the lenses you normally use. For example, being able to imagine that the dome, which is the main subject using 50mm, gradually appears closer when using 100mm, 200mm, and 300mm without looking in the viewfinder is useful when selecting lenses.

Was this article helpful?

0 0
Digital Photography Mastery

Digital Photography Mastery

Insider Secrets Revealed By the Pro Showing You How to Become a Professional Photographer! Discover The Secret Tips & Techniques On How To Be A Professional Photographer, Start Producing High Quality Pictures and Skyrocket Your Photography Business Income Revenue To The Roof TODAY! You're About to Discover the Powerful Strategies and Method to Start Taking Sharp, Clear and High Quality Pictures Like the Professional Photographer Without Paying a Single Penny to the Expert!

Get My Free Ebook


Responses

  • aman
    What are the interrelationship between lens,view finder?
    2 years ago

Post a comment