Digital Focus: Make Your Own Enlargements

Tips and strategies; the trade-off between resolution and image quality.

Dave Johnson

When I was a teenager, flush with the excitement of learning the craft of 35mm photography, I'd save my pennies--I worked for minimum wage hauling boxes of lingerie into Barney Stock and Sons--and every month or two, I'd turn my best photos into 5-by-7- or 8-by-10-inch enlargements. At the time, making oversize prints was a big deal for me, because special printings were somewhat expensive. I'd also have to communicate instructions to the photo shop about how I wanted the picture cropped and color adjusted; it was always a big deal.

These days, making enlargements isn't quite so dramatic. Equipped with virtually any modern ink jet printer, you can turn your digital images into frame-worthy prints as large as 8 by 10 inches. Large-format ink jets let you make truly huge prints, such as 13 by 19 inches.

Sizing Up Your Photos

Unfortunately, the bigger a print is, the more pixels it requires to maintain a sharp, high-resolution, photo-quality look. You probably already know that; what you may not know is exactly how many pixels you need for any given print size. Actually, it's pretty simple: If you're printing on an ink jet printer, you should use a resolution that gives you about 200 pixels for every measured inch in the dimensions of the print. If you're making an 8-by-10-inch print, for instance, the resolution of your image should be 1600 by 2000 pixels large (that's about what you get from a 3-megapixel camera at its highest resolution, by the way).

How can you tell how big your photo actually is? Your favorite image editing program can tell you. Try Paint Shop Pro, for instance. Load your picture and choose Image, Image Information from the menu. The resulting dialog box will tell you the image resolution in pixels. Divide both the X and Y dimensions by 200 to get a ballpark idea how large you can successfully print this image.

Get Creative

If you don't have enough pixels in your image, the result will be a blurry, pixilated mess. It's all a matter of perspective, though. Print a 640-by-480-pixel image on a sheet of 8-by-10-inch paper, for instance, and the result will be undeniably ugly. If you have a 1200-by-1500-pixel image, though, your print will probably look okay. The only way to be sure is to print it and see. Sometimes I'll crop a 3-megapixel image a bit, shaving off some unwanted pixels. In general, a moderately cropped photo will still look good on paper.

And don't forget--you don't have to stick with standard print sizes when you've got a digital printer. If you think your image is a bit blurry at 8 by 10, print it a little smaller. You can trim the edges of the paper with a paper cutter, sharp modeling blade, or scissors, and hang the completed image with a little matte paper to make it fit in a frame. Be creative--that's what digital imaging is all about.

Mini Review: Digital Camera Enhancer

Almost any photo can benefit from a little touch-up--and professionals rely on software like Adobe PhotoShop to sharpen detail, soften portraits, adjust off-kilter colors, and balance bad lighting. If you're not using an image editor to tweak your photos, you might be surprised at just how much you can improve your shots.

Find out how much better your pictures can be--for free--with Digital Camera Enhancer from MediaChance. This great little tool won't replace a full-featured image editor, but it does a few things very well. By manipulating a small handful of sliders, you can correct the color balance, enhance detail, adjust skin tones, and reduce digital noise (that's an effect that looks like multi-colored snow, caused when you take pictures in low light) in your photos. If you're not keen on tweaking these controls manually, the program can also adjust your photo automatically.

In general, the results are quite good. The software works best with photos that have lighting and color balance problems; if your image is already pretty good, Digital Camera Enhancer has a tendency to make it worse. You can preview your results right away and save the changes or abort the edit. It's hard to beat this program for quick changes that don't warrant opening a big program like Paint Shop Pro, and the price is right. Give Digital Camera Enhancer a shot.

Q&A: Image Quality Versus Resolution

My camera lets me control resolution and image quality. What's the difference?

-- Janice Wall

With a digital camera, you have two different ways to manage the visual quality of your pictures, as well as how many you can store in memory before having to swap memory cards or download pictures to your PC: resolution and image quality.

The resolution setting determines the physical size of the picture--that is, how many pixels are used. Typical resolutions include 640 by 480, 1024 by 768, and 1600 by 2000. If you set the resolution higher, you'll be able to make larger prints, but you'll fit fewer in the camera's memory.

Image quality has to do with how accurately the camera represents your pictures. Virtually all cameras use the.jpg file format for storing pictures, and.jpg is what's known as a "lossy" file format--it discards some information to make smaller files. A high image-quality setting creates fewer graphical glitches in your photo but takes more room to store. Low image quality saves lots of space, but sacrifices image quality.

Here's my suggestion: Always work with your camera's highest image-quality mode, but adjust the resolution depending on what you're doing. If you're shooting for the Web, take low-res images. If you want to make prints, use high resolution.

Send your questions to: dave@bydavejohnson.com.

Hot Pic of the Week

Get published, get famous! Each week, we select our favorite reader-submitted photo based on creativity, originality, and technique. Every month, the best of the weekly winners gets a prize valued at between $10 and $100.

Here's how to enter:

Send us your photograph in.jpg format at a resolution no larger than 640 by 480 pixels to hotpic@pcworld.com. Larger entries will be immediately disqualified. If necessary, use an image editing program to reduce the file size of your image before e-mailing it to us. Include the title of your photo, along with a short description of the photo and how you photographed it. Don't forget to send your name, e-mail address, and postal address. Before entering please read the full description of the contest rules and regs.

This Week's Hot Pic:

Savate by Rick Hodgson

Rick says: "I took this picture with a Nikon Coolpix 990 at my local kickboxing class. It's hard to capture action with a lot of digital cameras, so I'm happy with the way this shot came out. I set the camera to shutter priority and set a fairly slow shutter speed. Combined with the flash, I managed to get a sense of motion without overly blurring the image."