Still Photography Cameras I

1. Still Photography Cameras I A Lecture By: AMIT CHAWLA

2. Camera Parts All types of cameras should have: • Some means of accurately aiming & composing the picture. • Ability to focus precisely. • A shutter to control the moment of exposure & time for which the light acts on the film. • An aperture to control depth of field & intensity of light. • A method of loading & unloading film, without allowing unwanted light to affect it.

3. Other Optional Parts • Light Meter • Depth of Field Preview Button • Flash Light • Lens Changing Option • Tripod mounting ability etc.

4. Camera Types • Pinhole Cameras • View Cameras • Twin Lens Reflex • Compact Cameras/ Direct Viewfinder • Single Lens Reflex • Polaroid • Digital Cameras

5. Pinhole Cameras • Lensless camera. Tiny hole replaces lens. Light passes through the hole; an image is formed in the camera. • It is the simplest camera possible. It consists of a light-proof box, some sort of film and a pinhole. The pinhole is simply an extremely small hole like you would make with the tip of a pin in a piece of thick aluminum foil.

6. View Cameras • Earliest forms of photographic plate camera • It consists of 2 boxes one sliding inside other for focusing. • You can readily change lenses which are readily mounted on panel.

8. View Cameras • In this camera, the lens can be tilted or offset sideways, independently of the back. • These camera movements are especially important for architectural & still life photography. • They give the photographer an extra control over Depth of field and subject distortion (perspective correction).

9. Types of View Camera Designs: • Baseboard • Monorail

10. Its Advantages & Limitations Advantages of View Cameras • A huge range of camera movements. • One can image & process single exposure. • Relatively simple construction than others. • Choice of special film types available. Limitations of View Cameras • Bulky to carry • Slow to setup and use. • Image in the viewfinder is dim & also awkward to view. • Impractical for fast-moving situations like sports/candid photography.

11. TLRs • Twin Lens Reflex cameras fv use 2 lenses of identical f-length mounted one above the other on a panel. The above lens is used for composing while the bottom one is used for capturing the image. • The distance between the top lens to the focusing screen must be the same as the distance between the bottom lens and the film.

12. Parallax Error • The differences between the viewpoint of two lenses, give parallax error, especially with close subjects.

13. Its Advantages & Limitations Advantages of TLRs • Mechanically simple & compact design. • Handy and portable than View Camera. • You can see visual focusing effect even during the exposure itself. • It costs lesser than an SLR with similar quality lens. Disadvantages of TLRs • Parallax error creates difficulties with close-up work. • One cannot check the visual effect of Depth of Field. • Relatively bulky (than an SLR) for a 35 mm format. • Additional Lens are Rare & have to be bought in pairs.

14. Compact Cameras / Direct Viewfinders • Direct viewfinder / Compact cameras were the first small format point & shoot cameras. • They’re designed as self contained unit with everything built-in, including a Flash. • Most of the elements in this type of camera are automated in order to ensure a low failure rate & to make cameras a common man’s tool.

15. About Compact Cameras • These cameras mostly have a lens with fixed focal length between 35mm to 40mm. You compose by looking through separate optical view-finder unit. • As different lens are used for composing and capturing, these cameras also encounter parallax error. • Both, Aperture as well as Shutter speed, is set internally using an in-built light meter which measures brightness of light source.

17. Its Advantages & Limitations Advantages of Compact cameras: • All in one unit for quick ‘aim and shoot’ purposes. • Compact & Light weight than their older counterpart View cameras. • You can see visual focusing effect even during the exposure itself. • It costs lesser than any other camera design. Disadvantages of Compact cameras: • Parallax error was still a problem. • No convenient way of visually checking DoF. • No possibility of changing Lens. • Flash units are not very powerful & give only flat light.

18. SINGLE LENS REFLEX (S.L.R.) • SLRs were developed to overcome the problems with TLRs & compact cameras. The design avoids parallax error completely by using same lens for both viewfinding & capturing.

19. Working of SLRs • Hinged 45o mirror reflects image on to a pentagonal shaped block of glass called “Pentaprism”. It reflects light off its roof so that laterally reversed image is presented to the eye as straight image. • This mirror flips out of the way, just before focal plane shutter is fired.

20. More Information • The distance between lens & focusing screen via mirror is equal to lens to film distance. Thus what appears sharp on the screen will also be sharp on the film. • As same lens is used for both viewfinding & capturing one can also check the visual effect of DoF on pressing the DoF preview button.

21. Its Advantages & Limitations SLR Advantages • Ability to precisely compose the frame without parallax error. • Ability to check the visual effect of DoF on the image. • Vast range of lenses & accessories is available. • Key information such as that of exposure & focus are signaled directly on to the view-finder. SLR Disadvantages • One cannot see through viewfinder whilst exposure is taking place. • Electronically & mechanically it is more complex than other designs. • Enhanced camera movements are not possible. • Shutter speed settings for use with flash is limited.

22. DIGITAL CAMERAS • The digital camera perhaps the most remarkable instances of shift from Analog to Digital era. Conventional cameras depended entirely on chemical & mechanical processes. On other hand, digital cameras work on the mechanism of recording images electronically.

23. DIGITAL CAMERAS • In Digital photography, lens flashes the image on a sensor instead of a Film. This sensor (CCD) which is made of semi-conductor material captures image as a long string of 1s & 0s that represent all tiny colored dots / pixels.

24. Image Sizes • Resolution of the Frame is defined in Pixels • Image is converted to a specific size, compressed & then written to memory. • Then, you may transfer them to a computer or printer.

25. Its Advantages & Limitations Advantages of Digital Photography • You can manage your images collection on a computer. • Small size of many digital cameras makes them portable. • You can immediately view & delete photos. • You can choose the size & quality of images as you shoot them. • Images can be easily shared and printed. Disadvantages of Digital Photography • Good digi-cams are still expensive compared to film. • Cameras rarely have interchangeable lenses or are expensive. • A computer is needed for working on the images. • Most digital cameras are automated, giving photographer little direct control.

26. Instant Cameras • The instant camera is a type of camera with self-developing film. The most famous were those made by the Polaroid Corporation. Polaroid no longer manufactures such cameras since February 2008. The invention of modern instant cameras is generally credited to American scientist Edwin Land, who unveiled the first commercial instant camera, the Land Camera, in 1947, 10 years after founding the Polaroid Corporation.

27. Working of Instant Cameras • Polaroid cameras had a film/paper pack of the size 4”x5”. As soon as the exposure was made, the paper was pulled through the rollers that released the chemicals that would develop the print. In matter of few seconds the negative could be peeled of its negative fixed with a saturated pad provided with the film pack.

28. Its Advantages& Limitations