Checking resolution: Do you have enough pixels?

For good-quality prints, you need an adequate pixel population. Chapter 4 explains the role of pixel count, or resolution, in detail, but the short story is that you should aim for the neighborhood of 200 to 300 pixels per linear inch of your print. If you want to print, say, an 11 x 14-inch photo, your image needs to contain at least 2200 x 2800 pixels, or roughly 6 megapixels. (Here's the math: 11 inches by 200 equals 2200 pixels; 14 x 200 equals 2800 pixels; and 2200 pixels x 2800 pixels equals a total resolution of 6.16 million pixels, or 6 megapixels.)

Don't have enough pixels? Expect prints that look jagged along curved and diagonal lines and exhibit other visual defects. Also remember that even though some photo programs enable you to add pixels to an existing image, doing so never improves picture quality.

If you're printing photos at a retail or online site, the printer's order form usually indicates how large a print you can make given the image's pixel count. If you're doing your own printing, you have to be the resolution cop, though. You can find out how many pixels you have by looking at the image file properties during picture playback on the camera. (You may need to change the camera's display settings to do so.) For example, in Figure 9-3, the resolution value reports 4032 x 3024 pixels. (I dimmed everything except that value to make it easier to spot.)

You also can view resolution information in the photo software after you download pictures to your computer. For example, here's how to get to the resolution data in the free photo programs provided on Windows-based and Mac computers:

• Windows: In Windows Live Photo Gallery, click the image thumbnail, click the View tab (at the top of the image window), and click All Details, as shown in Figure 9-4. You then see the filename, the date the picture was taken, the file size (3.72MB in the figure), and the picture resolution (3697 x 2464). These instructions refer to the version of Windows Live Photo Gallery found in Windows 7; the process may be slightly different in other versions of Windows.

  Note that the file size value shown here (3.72MB, or megabytes) is not the image resolution, which is stated in megapixels. In this case, the megapixel count is roughly 9.1 megapixels (3697 x 2464 pixels equals about 9.1 million pixels).

• Mac: After launching iPhoto or Photos, track down the image thumbnail and then choose View ⇒ Info or click the i button in Photos or the Info button in iPhoto. You then see a box showing an assortment of picture settings, including the resolution. Figure 9-5 shows the window as it appears in Photos. (In iPhoto, the Info button is at the bottom of the screen instead of at the top.)

For pictures stored on your cellphone or tablet, you may be able to pull up resolution data in whatever photo viewer the device's operating system provides. If not, many third-party photo apps enable you to get the image file to disclose its hidden metadata. Of course, if you didn't crop the photo and your phone takes pictures at only one resolution setting, you can just check the phone's camera specs to find out the image resolution.

Getting print and monitor colors in sync

Aside from poor picture quality, the number-one printing complaint is that colors on the computer monitor don't match the ones that show up in print. When this problem occurs, most people assume that the printer is to blame, but in fact the most likely culprit is the monitor. If the monitor isn’t accurately calibrated, the colors it displays aren’t a true reflection of your image colors.

To ensure that the monitor is displaying photos on a neutral canvas, you can start with a software-based calibration utility, which is just a small program that guides you through the process of adjusting the monitor. The program displays various color swatches and other graphics and then asks you to provide feedback about what you see on the screen.

Both the Windows and Mac operating systems offer built-in calibration programs. If you use a Mac, look in the Displays section of the System Preferences dialog; the utility is called Display Calibrator Assistant. Windows 7 and 10 offer a similar tool named Display Color Calibration.

Software-based calibration isn’t ideal, however, because people’s eyes aren’t that reliable in judging color accuracy. For a more accurate calibration, you may want to invest in a device known as a colorimeter, which you attach to or hang on your monitor, to accurately measure and calibrate the display. Companies such as Datacolor (www.spyder.datacolor.com) and X-Rite (www.xritephoto.com) sell this type of product along with other tools for ensuring better color matching. Figure 9-6 shows the X-Rite ColorMunki Smile, for example, which has a suggested retail price of $109. As shown in the image, some products work with both laptop and desktop monitors, and some companies even offer tools designed for calibrating tablets. (Check the product specs to ensure compatibility with your screen and your computer or tablet's operating system.)

Whichever route you go, the calibration process produces a monitor profile, which is a data file that tells your computer how to adjust the display to compensate for any monitor color casts. Your Windows or Mac operating system loads this file automatically whenever you start your computer. Your only responsibility is to perform the calibration every month or so, because monitor colors drift over time.

If your monitor is calibrated, color-matching problems may be caused by any of these other, secondary issues:

• One of the print nozzles or heads is empty or clogged. Check the manual to find out how to perform the necessary maintenance to keep the nozzles or print heads in good shape.

• You chose the wrong paper setting in your printer software. When you set up the print job, be sure to select the right setting from the paper-type option — glossy, matte, and so on. This setting affects how the printer lays down ink on the paper.

  Some paper manufacturers provide ICC profiles, which are small data files that help your printer and computer better translate your image colors to the specific paper you're using. (ICC stands for International Color Consortium, the group that developed the universal color translator on which this system is based.) After you download and install the profiles, you should see the related paper types in the list of options in your printer settings dialog box. If you're using paper made by the printer manufacturer, though, you don't usually have to take this step; the profiles are automatically added when you install the printer software during initial setup.

• Your printer and photo software are fighting over color-management duties. Some photo programs offer features that enable the user to control how colors are handled as an image passes from camera to monitor to printer. Most printer software also offers color-management features. The problem is, if you enable color-management controls in both your photo software and your printer software, you can create conflicts that lead to wacky colors.

  Unless you're schooled in color management, I recommend letting your printer handle things. However, it's wise to do a few test prints to see whether results are better when you hand the job to your photo software. Check your photo software and printer manuals to find out the color-management options available to you and how to turn them on and off.

Even if all the aforementioned issues are resolved, however, don’t expect perfect color matching between printer and monitor. Printers simply can’t reproduce the entire spectrum of colors that a monitor can display. In addition, monitor colors always appear brighter because they are, after all, generated with light.

Finally, be sure to evaluate print colors and monitor colors in the same ambient light — daylight, office light, whatever — because that light source has its own influence on the colors you see. If your prints will be displayed in a gallery, you also should make sure that colors look good in whatever lighting the gallery uses. Ditto for prints you hang in your own home, of course.

Choosing a printer type

Cruise the aisles of your favorite office-supply or electronics store, and you'll encounter a few different print technologies, each of which has its pros and cons. The next three sections explain the most common options to help you decide which makes the most sense for the kind of printing you want to do.

Looking at other printer features

After you narrow down what type and size of printer you need, a few additional shopping tips can help you pick the right product:

• Don’t worry too much about the specification known as dpi. This abbreviation stands for dots per inch and refers to the number of dots of color the printer can create per linear inch. A higher dpi means a smaller printer dot, and the smaller the dot, the harder it is for the human eye to notice that the image is made up of dots. In theory, a higher dpi should mean better-looking images, but frankly, just about any printer you buy today offers enough resolution to output good prints.

  Don't confuse dip with ppi, even though many printer manufacturers (and online “experts”) use the two terms interchangeably. Ppi measures the resolution of the digital photo file (ppi stands for pixels per inch). Many printers use multiple dots to reproduce one image pixel.

• For inkjets, look for a model that uses four or more colors. Most inkjets print using four colors: cyan, magenta, yellow, and black. This ink combination is known as CMYK. (See the sidebar “The separate world of CMYK,” later in this chapter.) But some lower-end inkjets eliminate the black ink and combine cyan, magenta, and yellow to approximate black. Approximate is the key word — you don’t get good, solid blacks without that black ink, so for best color quality, avoid 3-color printers.

  Some high-end photo inkjets feature six or more ink colors, adding lighter shades of the primary colors or several shades of gray to the standard CMYK mix. The extra inks expand the range of colors that the printer can manufacture, resulting in more accurate color rendition, but add to the print cost.

• If you're a black-and-white photo fan, look into printers that offer special ink combinations designed for that purpose. Such printers often have two or more black or gray cartridges, for example, to better render all the tones in a black-and-white image. However, before you invest in this type of printer, compare the price of the printer (and ink and paper) with the cost of having the job done at a lab. You may find that you can get better results, for less money, by having a pro lab output your black-and-white prints.
• Inkjets that use separate cartridges for each color save you money. On models that have only one cartridge for all inks, you usually end up throwing away some ink because one color often becomes depleted before the others. With multiple ink cartridges, you just replace the ones that are running out.
• Compare print speeds if you’re a frequent printer. If you use your printer for business purposes and you print a lot of images, be sure that the printer you pick can output images at a decent speed. And be sure to find out the per-page print speed for printing at the printer’s highest-quality setting. Most manufacturers list print speeds for the lowest-quality or draft-mode printing. When you see claims like “Prints at speeds up to … ,” you know you’re seeing the speed for the lowest-quality print setting.

• Computer-free printing options give you extra flexibility. Some printers can print directly from camera memory cards — no computer required. Several technologies enable this feature:

  • Built-in memory card slots: You insert the memory card, use the printer’s control panel to set up the print job, and press the Print button. Be sure that the printer offers card slots that are compatible with the type of memory card you use, though.
  • PictBridge: This feature enables you to hook up your camera to your printer via USB cable for direct printing. (Both the camera and the printer must offer PictBridge capabilities.)
  • DPOF: This acronym, pronounced “dee-poff,” stands for digital print order format and enables you to select the images you want to print via your camera’s user interface. The camera records your instructions on the memory card. Then, if you use a printer that has memory card slots, you put the card into a slot, and the printer reads and outputs the “print order.” Again, both the camera and the printer must offer DPOF technology.
  • Wireless connections: Manufacturers are offering a number of Wi-Fi and Bluetooth-enabled printers, too. If you use a camera or memory card that offers wireless connectivity, you can send your pictures from the camera to the printer wirelessly.

  Of course, direct printing takes away your chance to edit your pictures; you may be able to use camera or printer settings to make minor changes, such as rotate the image, brighten the picture, or apply a prefab frame design, but that’s all. Direct printing is great on occasions where print immediacy is more important than image perfection, however. For example, a real estate agent taking a client for a site visit can shoot pictures of the house and output prints in a flash so that the client can take pictures home that day.

• Research independent sources for cost-per-print information. Consumer magazines and computer publications often publish articles that compare current printer models based on cost per print. Some printers use more expensive inks than others, so if you’re having trouble deciding between several similar models, this information could help you make the call. Note that some printer ads and brochures also state a cost per print, but the numbers you see are approximations at best and are calculated in a fashion designed to make the use costs appear as low as possible. As they say in the car ads, your mileage may vary.
• Read reviews and blog comments for other input, too. Once again, it pays to check out reviews in magazines and online sites to find detailed reviews about print quality and other printer features. You also can get lots of good real-world information by searching out blogs and user forums where people discuss their experiences with models you’re considering.

Sizing photos for screen display

How many times have you received an email message that looks like the one in Figure 9-8? Some well-meaning friend or relative sent you a digital photo that’s so large you can’t view the whole thing on your monitor. (Again, Chapter 4 explains why high-resolution photos take up so much screen space.)

Fortunately, the latest email programs have tools that automatically adjust the display of large images to make them viewable. Even so, that doesn't change the fact that sending someone a mega-resolution picture means that you're sending them a very large file, and large files mean longer downloading times and, if recipients choose to hold on to the picture, a big storage hit on their hard drives.

Sending a high-resolution photo is the thing to do if you want the recipient to be able to generate a good print. But for simple email sharing, I suggest limiting photos to about 800 pixels on the longest edge. This limit ensures that people who use an email program that doesn’t offer the latest photo-viewing tools can see your entire picture without scrolling, as in Figure 9-9.

The same sizing usually works well for Facebook and other social media sites, but check the site's image restrictions before you post. If the picture will be used on a business website, the web administrator or designer should be able to tell you the size guidelines to follow.

Saving files in the JPEG format

In addition to paying attention to file size, you need to be sure that your files are in the JPEG file format, which is the only format that's sure to be viewable in all web browsers and email programs.

What about PNG (pronounced “ping”) and GIF, the other two online formats you may encounter? Well, PNG is a less-common image standard on the web, so I don't recommend that option. And GIF files can contain only 256 colors, so photos appear splotchy when saved to this format, as illustrated by Figure 9-10. GIF is designed for logos and other simple graphics that contain only a few colors.

People argue about whether to say “jiff,” as in “jiffy,” or “gif,” with a hard g. I go with “jiff” because our research turned up evidence that the creators of the format intended that pronunciation, but it doesn’t matter how you say GIF as long as you remember not to use it for your web photos.

To avoid some potential confusion when you take the step of saving your JPEG files, here's advice about a couple of options you may encounter:

• Quality: When you save a file in the JPEG format from inside a photo-editing program, you usually see an option named Quality. In some cases, you may find this feature instead provided within the overall program-preferences settings; in that case, the program uses the same setting for all files you save in the JPEG format.

  Either way, the Quality option relates to the how the JPEG format achieves its smaller file sizes, which is to remove some of the original picture data from the file — a process known as lossy compression. A higher Quality setting results in less lossy compression, which translates to a better-looking image but a larger file size. As you lower the Quality setting, more data is tossed, the file size shrinks, and the image quality is further degraded.

  The good news is that if you first reduce the resolution of your photos, taking the pixel count down to a size appropriate for online use, your files shouldn't be too large for most online uses even if you select the highest Quality setting (least amount of compression). Remember that with onscreen images, pixel count only changes the size of the display, not the quality, whereas the amount of JPEG compression does affect picture quality. See Chapter 4 for more on this issue.

• Progressive: When you save a picture in the JPEG format inside a photo editor, you usually encounter an option that enables you to specify whether you want to create a progressive image. This feature determines how the picture loads on a web page. With a progressive JPEG, a faint representation of the image appears as soon as the initial image data makes its way through the viewer’s modem. As more and more image data is received, the picture details are filled in bit by bit. With nonprogressive images, no part of the image appears until all image data is received.

  Progressive images create the perception that the image is being loaded faster because the viewer has something to look at sooner. This type of photo also enables website visitors to decide more quickly whether the image is of interest to them and, if not, to move on before the image download is complete. However, progressive images take longer to download fully, and some web browsers don’t handle them well. In addition, progressive JPEGs require more RAM (system memory) to view. For these reasons, most web design experts recommend that you don’t use progressive images on web pages.

• File naming: If you're saving a low-resolution copy of a JPEG original, be sure to give the copy a name that's different from the original. Otherwise, the full-resolution version will be overwritten by the smaller file. You may even want to save your screen-size images in a separate folder so that you can track them down more easily when it's time to upload them to their final online destination.