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Cameras I
Basic operation and features
Why Digital?
With digital photography you can do things that you can not do with film:
• Snap anytime- there is no cost until you print!
• There is no such thing as a roll of film. Snap 2, 10 or 100 photos at a time.
• Use the camera’s automatic mode – a computer helps take a great picture.
• Review the picture immediately after you snap it. Delete and re-snap if required.
• Print what you want, when you want.
• Sa
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Digital v. Film: Camera Sales 90 80 70 60 Digital Worldwide 50 Digital US 40 Film Worldwide Film US 30 20 10 0 1999 2000 2001 2002 2003 2004 5.5 11 18.5 30.5 50 78 Digital Worldwide 2 4.3 6.5 11.5 17 23 Digital US Film Worldwide 67 71 66 63 57 49 16.8 20.6 191916 13 Film US Year We are in the midst of a technological revolution that rivals the inventions of the automobile, the telephone, the television and the computer. Only this revolution is happening much faster. Over 23 million digit
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shutter button and lens are virtually the only parts of the camera that remain in digital cameras. The film has been replaced with a light sensitive chip, called a Charge Coupled Device (CCD). This chip is an array of millions elements that are sensitive to light. When light hits an element in the CCD array, a electrical charge is accumulated at a rate determined by the amount of light striking it. This charge is then measured by an analog to digital converter that converts the voltage t
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The block diagram shows a fast microprocessor, memory, a color display and buttons for a user interface; with a power supply for rechargeable battery operation. That would be a good description for a laptop computer. Add the lens and the CCD module and you have a camera! All of this processing power means that the camera can make many calculations and decisions while you take the picture. Before the shot: • Display options on the screen and allow the user to change them with the but
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What the heck is a megapixel? Mega is a prefix that means million. A pixel refers to the element on the CCD that captures light. Thus a 4 megapixel camera has approximately 4 million sensing elements on its CCD. The megapixels a camera has nothing to do with the size of the image, but has everything to do with resolution. You can get a print of any size with any camera, but the image quality will be better the higher the resolution. Here is an extreme example: 1600x1200 pixels 80
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Remember: while you can always decrease resolution using editing software, you can never increase it. A rough rule of thumb is that the memory required per picture is one half of the megapixel rating of the camera. Thus a 4 megapixel camera will require 2 Mbytes of storage per picture. Professionals put the resolution required for parity with film at about 250-300 pixels per inch. Thus for an 8x10” print, a 6 megapixel camera would be required. This rule is somewhat subjective. Most
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Can you see the difference? You can probably tell that the 1 megapixel camera is not as good for 8x10s. It is still adequate for email or eBay work but not acceptable for taking quality pictures that will be enlarged. Is 2 megapixels enough? That is up to you: it may be, if a camera has other features you like. Certainly by the time you get to 3, 4 or 5 megapixels you are going to get quality prints (in my opinion). If you are a person who will accept nothing but the absolute best quality,
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Many cameras offer a digital zoom in addition to the optical zoom. That’s ok. If you never use the digital portion, which is activated automatically when the limit of the optical zoom is reached, then you never suffer a loss of resolution. It is always there if you really need it. Do you need greater than 10x? A professional camera with changeable lens system is your best bet. Get the checkbook ready! LCD screen LCD stands for Liquid Crystal Display. Are the acronyms getting to yo
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Remember the rule of thumb for storage? One half the megapixel rating per picture. So a 4 megapixel camera will require 2 megabytes of storage per picture. Thus the 32 mbyte card that came with the 4 megapixel camera will only hold 16 shots. 16 shots is not enough for a good afternoon, especially if you decide to shoot some video. Unfortunately, in an effort to save money most digital cameras come with only a small memory card. Plan on buying a 128 or 256 megabyte card when you buy the came
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Good, Better, Best or Normal, Fine, Superfine At the highest quality, Best or Superfine, the compression removes only the artifacts that the JPEG scientists decided that humans cannot resolve anyway, in other words the picture quality is near perfect. Setting your camera to the lower quality setting, with higher compression, will result in the algorithm reducing the detail in the picture, reducing the file size and also reducing the detail in the image. Highly compressed images can lo
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are spread over a larger area so apparent distortions are lessened. Professional quality cameras have large lenses with large objectives. Higher zooms require more light and a larger objective lens. Of course cameras with such lenses won’t fit in your pocket. Cleaning the lens of a camera Lenses are extraordinarily fragile, and once damaged cannot be repaired. When light hits the surface of the lens, some is reflected and some is transmitted through the lens. Most of the light that i
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new disk drive. Newer operating systems, such as Windows XP may do this automatically, older operating systems, particularly Windows 98 and ME, will require that you install drivers from the included disk. After you plug the cable into the computer, leave it there. Don’t carry it around with you. It is difficult and expensive to replace. If you need to access the pictures on the road, use a “card reader.” These will allow you to read the pictures off the card directly without the spec
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Microsoft Picture-It, (free with XP?): Pretty limited, but good for simple tasks. Make sure that the software (and the drivers for the camera), are compatible with your own computer. If you are running Windows 95 or a Macintosh, you are likely to have a more difficult time finding a camera and software that will work with your computer. Windows 98 is OK, Windows 2000 and XP work well also. What can you do with photo editing software? Most of the time photo editing is about sharing. F
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The final result Photo restoration: The following severely damaged file was restored using Photoshop Elements: 13
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File types Different file types can be determined by the suffix on the file name, for example, a JPEG file might be called “filename.jpeg” or “filename.jpg.” The most common file types are sufficient for most uses, they are: JPG: example: “filename.jpg” or “filename.jpeg.” This is the native or internal file format for most cameras. It is the best starting and ending point for photo editing. It is a compressed format, and you will get good results even with small files. Rule of thumb
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tend to be smaller and are definitely more expensive, and standard size batteries that you can buy in any electronics, grocery or drug store. Proprietary battery packs: If you opt for a very small camera you are going to get a special small battery supplied by the manufacturer. If you want a second back-up battery they are expensive, $40 to $50. The advantage to these batteries is that they are small and light. The downside?...if you run out of power at a remote location you‘d better
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Some other common features on many cameras There are a number of other common features on most digital cameras. Most cameras have the following modes. • Automatic: The camera makes the decisions: It makes pretty good ones most of the time! • Manual Mode: Set the flash on to fill or adjust the exposure manually. • Movie Mode with sound: Take full motion videos for computer viewing and editing. • Self Timer: Put the camera on a tripod and take a picture of yourself. • Macro Focusing:
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Both of these ads appeared in the Sunday paper. There are three cameras in them that you should not buy. Can you spot them? Hint: Digital zoom without an optical zoom is not a good option. It turns out that the Polaroid camera will take a memory card, although one is not included. It doesn’t matter anyway because it does not have an optical zoom. 17
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Printing at the digital kiosk You don’t need a computer to enjoy the benefits of digital photography. With the introduction of digital kiosks in many photo, discount and drug stores you can select, edit, make prints and burn your photos onto a CD without ever getting near a computer. The photo at right is a kiosk at a well known department store. The machine is linked to the normal photo processing machine, so photos pop out as they normally would with film. You order the prints u
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Addendum Copyright law If you take a picture with your camera, you own it. You can copyright it, print it, sell it and freely modify it. If you use someone else’s copyrighted image, from the internet for example, you lose some of these rights. Unless you obtain permission of the original photographer or the owner of the photograph, you may have no rights to use that photo or any part of it in any commercial way. Under the principle of “Fair Use,” you are generally allowed to use copyr
