PDQ Library:  Digital Photography

Digital camera advantages:
These camers are convenient, and you can view your photos, mistakes and all, right away. It can save enormously on printing costs if you take a lot of photos but keep or print only a few. You will save money on developing and printing costs using a digital camera. If you print every photo on your home printer, the cost of colour cartridges, paper and printer will likely be higher than commercial printing services. It's very useful if you never print photos but publish them on Web pages.

Digital camera disadvantages:
Photographers who like control over shutter speed and aperture plus other features will find that a digital camera, with equivalent features for creating high quality photos, is more expensive than a film camera.

Camera features:
Do you want to send your photos by Email and publish them on a Web page or print and enlarge them? Each of these might require different resolution or size settings on your digital camera or even choosing a better quality camera. Printing requires a high quality image and computer display requires fast loading (small file size). Both are very different requirements.

For Web sites, Email or displaying on your screen, you can use the most basic camera (1MB will do). If you want professional photos enlarged to 11 X 14, you will have to use a high-end (more expensive) camera with a better quality lens and extra features, resultion and storage capability. You should check out digital video recorders which can also be used for taking still images. Some digital cameras are hybrids that can take still pictures or short videos (movies).

Scanner option:
If you send only a few photos by Email, and have a large backlog of prints to digitize, a scanner might be more useful than a digital camera. A scanner can convert prints into image files you can save, publish to the Web or Email. It has the added advantage of being able to scan (paper) pages of text, which you can then convert to a document file using OCR (optical character recognition) software. You can also use a scanner with a modem and fax software as a fax machine.

Faxing photos:
Faxing requires 200 dpi for reasonable quality at the receiving end - check this image property using your image software. In your photo editing software, you may have to resize a large picture to fit a normal fax page (8.5 X 11 inch). Convert your photo to gray-scale, make sure the image is 200 dpi, then alter brightness or contrast if it improves the appearance. FAX transmission will not "print" the best quality photo but you can come close.

Camera settings:

Picture Quality:
Most cameras save photos in the JPEG (JPG) format, a standard Web image format. JPEG is a compressed format to save storage space and is known as a "lossy" format. Compression causes loss of picture quality as the file size gets smaller, but is usually not noticable on a Web page or Email. Some cameras use uncompressed TIFF format - this high quality format takes up the greatest amount of storage space and is available only on more expensive cameras.

Camera picture quality is expressed with terms like "Good, Better, Best" or "Standard and High". You will have to refer to your manual to what terms are used for your camera. Generally, the highest quality combined with highest resolution settings will result in the best quality pictures for printing, creating the largest file size. This means you can take the fewest number of pictures before your camera storage is full. It also results in the slowest downloads for people viewing them on the Web or by Email.

Resolution is measured in pixels on a computer monitor - a typical 15 inch computer monitor, which is 11 inches across set in your system to display 800 X 600 pixels (default is 640 X 480), will display about 72 pixels per inch.

Photo Size:

Image size (in pixels) - approximate file sizes for best quality setting:
2048 X 1536   3 MB
1024 X 768   1 MB (XGA)
800 X 600    700 KB (SVGA)
640 X 480    40-85 KB (VGA)

VGA is the default setting for many computer monitors even though they are capable of higher settings. On some cameras, the largest resolution setting will create an image that will not fit on the screen of a normal computer monitor and you will have to scroll up and sideways to see it all. For example, if your monitor is VGA, then a horizontal photo taken using that setting will be 640 X 480 pixels and will fill your screen. The same photo displayed on a high-resolution monitor set to 2048 X 1536 would fill about a third of the way across the screen and fill 10% of the area. A photo size of 2048 X 1536 would contain 3.34 Megapixels (3 million pixels).

Best quality with XGA size will result in picture file sizes of about 400 Kilobytes each. A 4 MB flash card in a camera will store about 10 images at that quality.

How to Choose Settings

You should experiment with a digital camera to see the difference yourself - take the same picture at all setting combinations and make notes about file size and picture quality on your computer monitor and printed out. These notes will come in handy for future reference.

Web and Email:
If you are using the photos for Email or Web pages, a "Good" or "Basic" quality with VGA size will likely be adequate with file size will be in the 40-85 KB range. If images are larger than that, you should be wary of putting more than one on a Web page. People get very annoyed when pages take more than 15 seconds to load and often leave or press the "STOP" button. An image that is 2" wide on the screen will load much faster than one that fills the screen. Always use photo editing software to resize your images for a Web page - never resize them using HTML image attributes.

Print publishing:
You will probably need maximum quality and size settings (in the 1-3MB range) for printing. For magazine publishing, you may discover your camera is not up to the job! To submit photos to a professional print shop, images usually must be a resolution of 300 dots per inch - or 300 DPI, which will be equivalent to the highest quality settings on your camera.

Stealing Images off the Web:
If you check most Web sites, you will notice a Copyright notice at the bottom. That means that you may not use any images, code or information without permission of the creater. In Canada, this right is inherent in law. You own copyright on your original creation without doing a thing. Of course, you have to be prepared to protect your copyright - which could be expensive. Proof of authorship is fairly easy with images, which are date-stamped at date of publishing and are rarely changed.

Protect your original images:
If you are concerned about plagarism of images from Web pages, you could deface them with text (e.g. your name) or add digital or image "watermarks" using software (e.g. Photoshop).

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