Absolute Beginner's Guide to Digital Photography

The best photo papers for longevity are made of 100% cotton and are acid-free.

Cotton papers can last decades, but don’t have the “pop” plastic papers contain.

The two most important factors that affect the quality of paper are the presence of

impurities and an acidic pH. Finished papers may contain natural impurities, such

as lignins (glues that hold plant cells together) that have not been removed during

processing, and unnatural impurities such as residual chemicals like sulfites, which

are not washed out during final processing.

Why Do Images Look So Good on the Monitor?

The monitor has the lowest resolution of any device in your computer system. An

older monitor is only 72 ppi (pixels per inch); Sony monitors and other more mod-

ern monitors use a shadow mask of 96 ppi. Even LCD screens are up to 100 ppi. So

why do images look so good on a monitor? Two reasons:

■ Backlit illumination. Have you ever seen an illuminated billboard on the

highway? Notice how much better it looks than a front-lit billboard?

■ Phosphor intensity. Every phosphor onscreen can produce the intensity of

every pixel in an image. This differs from an inkjet printer, which can only

produce a dot or leave the area blank. Basically, the monitor can generate

255 intensity values (0–255), whereas a printer can only generate two (a

blank or a dot).

Printing Big Pictures

A good scanner will enable you to scan in an

image and print it much larger than its original

size, but only a few times larger. If you really need

to print large images, a film scanner is required.

Film scanners can scan at a much higher resolu-

tion. A Nikon scanner, for example, can scan at

4000 samples per inch. Granted, a 35mm nega-

tive is much smaller than a print, but even this

size will enable you to print images up to 16× 20

inches with no noticeable grain. The big prob-

lem is the cost.

Some scanner manufacturers have created more

advanced flatbed scanners that include negative

and slide “sleeves.” You place the negative in the

sleeve and place it on the flatbed scanner (see

282 ABSOLUTE BEGINNER’S GUIDE TODIGITAL PHOTOGRAPHY

tip

Film scanners have a much

higher “dynamic range,”

which is the capability to

pick up details in the shad-

ows. When you scan a print,

detail is lost considerably in

shadow areas. Scan film

negatives and slides for maximum

quality and dynamic range.