Orlando Chapter STC - 47th STC Conference

Professional Development

Notes from 47th International STC Conference
Orlando, Florida, May 21-24, 2000

Digital Imaging: from Camera to Cropping

Diane Knerr, Michael Starr, and Brenda McGuire

The speakers represented Centromine, Compuware, and Battelle, respectively. Knerr, a recent graduate of Bowling Green State University's Master's Degree Program in Scientific and Technical Communication, authored the accompanying paper in the Proceedings.

Session Description: This panel discussion provided information on how to effectively incorporate digital images into information development projects.

Slides: View slides from the presentation.

What is Digital Imaging? -- Diane Knerr

Note: Presenter is with Centromine, a totally Web-based medical services company.

Analog = information presented in continuous form; a representation of the real world.
CCD = charge-coupled device. Light passes through lens and creates electronic image.
Compression: reduced file size.
Digital image image composed of discrete pixels, each with a brightness value
Pixel: Acronym for "picture element." It is the smallest discrete spatial component of a digital image.
Digitize: to convert into digital form.
Resolution: image quality defined by image's width and height measured in pixels.
Digital imaging is a process that converts photographic images into their mathematical equivalents, to produce a picture on the computer screen.
Three elements of digital imaging: acquisition, enhancement, and output.
Continuous-tone image: conventional photograph from film camera.
Digital image: tiny points of light with assigned brightness values.
In a digital camera, the light image passes through a color filter which separates the image into RGB colors, then to a CCD that converts the RGB pixels into electronic values, and then to a converter (from analog to digital).
Digital imaging has become integral to a great many professions, from medical diagnostics to law enforcement and forensics.

For technical communicators, digital imaging is important because:
It can enhance documentation with less effort
It can make your skills more marketable
It may help sustain employment
It can add a new dimension to your career (as well as your personal life).

The ABCs of Buying a Digital Camera -- Michael Starr

Note: Presenter works for Compuware.

Resolution: Online use is limited to 72 dpi. Hard copy can go up to 300 dpi.
Width x height = pixels. 1 Megapixel = 1M pixels.
Storage media: removal vs. flash card. Flash card is very limiting. Removable storage media add flexibility. 8 MB holds about 100 images.
Sony Mavica: quality limited by disk size.
Glass lens is important, because plastic scratches easily.
Lens options include zoom (true zoom is important vs digital...digital zoom loses quality), macro, telephoto. Telephoto demands much light.
CMOS = complementary metal-oxide semiconductor. Cheaper, more power-efficient than CCD, but sacrifices image quality...therefore limited to low-end cameras.
Price is driven by features, not just resolution and optics. Comparison-shop on the Web; prices vary widely.
Flash: Internal flash gives you 3-8 feet; further is useless, closer risks overexposure. External flash is important for longer distances.
LCD and viewfinder: LCD is difficult to use when taking pictures, but very useful when viewing pictures. Viewfinder (TTL) is invaluable for taking pictures.
Top Ten Accessories, in reverse order:

Imaging, organizing, and management software
Archiving CD-ROM media (note that approximately 36 rolls of film and development = price of a decent digital camera)
Lighting kits
Photo-quality printer
Photo-quality printer paper
Memory reader hardware
Memory reader software
Protective carrying case
Rechargeable batteries: Nickel metal hydrides are best...50 pictures plus 300 recharges.
Storage media

E-Film is an attachment that lets you take digital pictures with a 35mm analog camera.
Palm Pilot now has an attachment for a digital camera.
PIE = Picture Information Extractor. Names images by exact time they were taken.

What to Do with Those Digital Images -- Brenda McGuire

Note: Presenter works with Battelle.

Books on digital imaging:

Image manipulation software: very wide range of products, from $50 to $700.
Image organization software. Orderly, systematic file naming is important for archiving, creating virtual photo albums. Range from $40 to $80
Image organization Web sites also exist, to support sharing with remote friends and families.
Digital Camera Magazine has published a Buyers' Guide with ratings.

Best overall value: Microsoft Picture It
Best organization software: Cerious Software Thumbs Plus 4.0
Best manipulation software: Adobe PhotoShop 5.5. Tough to learn, but definitely the best.

Exposure value: Avoid using brightness/contrast in PhotoShop; instead, use Levels. This lets you independently manipulate shadows, midtones, and highlights, as well as separate RGB channels.
Contrast: Adjusting this can give your image more life. Adjust to a classic S-curve to bring out sharpness.
Special effects: Experiment...but first, save the image! Save the background layer and then work in successive layers for color filters, etc.
Resolution: Consider the output (print, presentation, Web). Use drives resolution. Resolution drives camera price.
JPEGs are half the size of comparable TIFFs but have lossy compression, which loses part of the image. JPEGs decompress when imported into presentations, which slightly changes the value of the image. JPEGs should be saved with maximum resolution to preserve as much of the image as possible.
Tradeoff is file size vs. image quality. Suit the resolution to the use; don't "overkill."
GIFs are not suitable for print or presentations (lowest resolution), but take up the least space on the Web. Can have transparent background. Can be animated. Both are very useful features for Web applications.

Questions and Answers

Longevity of paper prints? Varies. Ink does tend to fade with time. It is often water-soluble as well. On the other hand, if you keep good archives, you can always print another one.
Digital imagery can lessen the need for professionally developed graphic imagery.
If you need high-res, immediately convert the JPEG image into a TIFF. Each time you open a JPEG file, image quality degrades slightly.
Megapixel camera will provide 300 dpi prints for documentation use.
Super high-end quality such as advertising images still demand optical capture and high-res scanning.
Shoot close in rather than cropping...that preserves image quality.

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