After viewing your digital photo masterpieces on your computer screen, sending them to friends and family via email, or posting them on your web page, eventually you’re gonna find someone (maybe even you) who wants a good old-fashioned print. Armed with your photo quality ink-jet printer and paper, your image editing software, and this article, you’ll be ready to make prints that Mr. Kodak himself would be proud of.

How does an ink-jet printer work? Simplistically, it turns pixels into dots. Your printer (either by way of your computer, or on some models, by itself), interprets the digital data about each pixel in your photo, then sends a print head containing hundreds of ink nozzles across the paper, spraying ink droplets to “re-create” the pixels in your picture.

Older printers use four colors of ink: cyan (blue), magenta (kinda pink), yellow (duh, yellow) and black. Newer printers add two more colors: light cyan and light magenta. The bottom line is these colors are combined to create the many dots of color that make up your photo.

You’ll remember that earlier in this series we defined photo resolution in terms of dots per inch (dpi). Basically, on photo-quality paper, 300 dots per inch are more than enough to make a “suitable for framing” print. Remember we also talked about a 1600 x 1200 pixel digital image, and how at 300 dpi, that image would end up being about 5 inches by 4 inches when printed?

So how does all this relate to using your image editing software, like iPhoto or Adobe Photoshop Album, to get a good print? Say your printer has an advertised resolution of 1440 dpi (low by today’s standards), more than enough to give you the 300 dpi I said would make a good print. You want to print that 1600 x 1200 pixel image we talked about before. You soon notice that your image editing software only asks you what size print you want, in inches – it doesn’t really care about dpi (at least on the surface). Forgetting everything you’ve learned, you tell your software to make you an 8 x 10 inch print.

You’ll get an 8 x 10 print, all right, cause computers just do what they’re told (“Open the pod bay doors, HAL”). Unfortunately, you’ll be disappointed by the quality, because that print will only have 160 dots per inch, which means each dot is made bigger, which means less sharpness and less vivid color (and less oohs and ahhs). ‘Nuff said.

What else can you do to make your photos look better? Some image editing applications have a “blemish” tool, with which you can “erase” unsightly pimples, stray hair, or the dreaded “red eye” from flash photography. “Red eye” happens when the light from the flash enters the subject’s eye and reflects off the retina and back out to the camera. Since the retina is full of blood vessels, the reflected light is red. To combat this, some cameras have a “red eye reduction” flash setting. When this is used, the camera emits short flashes of light just prior to taking the picture, causing the subject’s iris to close, so there’s no reflection from the retina. If your camera doesn’t have this feature, you can head off “red eye” by increasing the ambient light around the subject, or have them not look directly at the camera.

Next time we’ll continue with more tips on editing and improving your digital photos, and archiving those shoeboxes full of old prints and negatives. Hint: think scanner. Until then – stay in focus!

© 2003 Peter F. Zimowski