One of the futurist forecasts back in the 1950s was that we'd soon have thin TV sets hanging on the walls just like paintings. For decades nothing happened and TVs got bigger and fatter every year. It's just within the past few years that the first hints of the future began to appear. One of these hints is the digital picture frame that displays slide shows and movies, with or without audio. Thin these may be, but cheap they are not. However, if you want to have an ever-changing slide show of your images, you might want to check into these devices. Some even let you, or others you invite, change the images on display from anywhere in the world.

While researching these devices, you'll find that on-line user guides, often in PDF format, let you really see what you are getting into. If the manufacturer doesn't put their guide on line, you should at least expect detailed specifications. The many sites that provide neither should probably be avoided or given extra scrutiny.

Following are some things to think about when considering a digital photo frame.

Screen Characteristics

Screen quality is really what it's all about and it's hard to evaluate without actually seeing frames side by side. This requires a trip to a store and it won't be easy to find a store that displays even one of these frames in action. You'll find that styles vary widely, but all are designed to look more or less like traditional photo frames, and some even incorporate traditional mats. Designs range from elegant to those that look like they were produced in a high-school woodworking shop. There also seems to be a feeling on the part of some manufacturers that they can make the device more appealing by adding a wide frame to a small screen.

• Size and resolution are two of the key determinants of the quality of the displayed image and the price of the frame. Specs are hard to come by so comparisons are almost impossible but the relation between these two features is critical. Available resolutions are much like those on other digital devices; 640 x 480, 800 x 600, 1024 x 768 and 1280 x 1024. For any one of these resolutions image quality will decrease as the screen gets larger because the available pixels are spread over a larger area.

  To calculate the pixel density of a screen you first calculate the screen's viewing area and resolution. For example, if the screen is 4 x 6 inches and the resolution is 640 x 480, 4 x 6 = 24 square inches and 640 x 480 equals 307, 200 total pixels. You then divide the total pixels by the square inches to find the pixels per square inch-307200/24=12,800 pixels per inch. The square root of this number will give you the pixels per inch, in this case about 113.

  Higher numbers are better, but exact comparisons can only be made between screens of roughly the same size.
• Pixel pitch is the distance between pixels center to center and smaller numbers are better. This number gives you an idea of the density of pixels and will be larger on a large screen with low resolution.
• Number of colors has a huge impact on how good your photos will look. Low-quality screens will have thousands (usually 256,000) and high quality screens will have millions.
• Display technology also has a huge effect on how good your images appear. The best screen technology is currently active matrix thin film transistor (TFT).
• Adjustable brightness, especially auto adjustment, improves the display of your images as the ambient light changes.
• Viewing angles indicate the angles at which images can be viewed horizontally and vertically. Higher numbers are better.
• Contrast ratio is the difference in brightness between pure white and black on the screen. Higher numbers are better.
• Style, or the "look," of these frames vary widely. However, you aren't locked in to a given look if your frame lets you change frames, sometimes called bezels, and mats if the device uses them.
• Display and mounting. Many frames offer both table display and wall mounting. (Remember wall mounted frames still need an electrical connection so there is an unsightly wire to deal with).
• Orientation on some frames can be changed to portrait or landscape orientation and when you rotate the frame the photos should rotate to match. When the frame is in landscape mode, portrait photos appear much smaller. When the frame is in portrait mode, landscape photos are the ones that appear smaller.
• Aspect ratio often determines if an image is cropped for display. (Ideally a frame won't crop your images or at least give you the option of a full-image display). On screens that do crop photos with an aspect ratio different from the screen's, two sides are cropped so the screen is filled by the central portion of the image. If you want control over this process you can crop your images in a photo-editing program before sending them to the frame. A few frames can display images in an HDTV aspect ratio of 16:9 but most use the TV aspect ratio of 4:3 or the 35mm film ratio of 1:1.5. Be careful when considering aspect ratios. HDTV shaped frames may look sexy but one new one has a resolution of only 480 x 234. If you display portrait oriented images they will either be very small on the screen or heavily cropped.
• Analog or digital. Digital screens are better so companies that use older analog technology usually omit any reference to it in their frame's specifications. Generally you can identify analog panels because their resolution differs from the standard sizes used in digital devices— 640 x 480, 800 x 600, 1024 x 768 and 1280 x 1024. Instead their resolution will be something like 960 x 234 or 480 x 234.

Feeding Images to the frame

For images to be displayed on a frame it must have access to them. You'll find there are a number of approaches taken to feeding images to a frame, many of which let you invite others to add photos to the show from anywhere in the world.

• Memory cards are the most common way to feed images to a frame. Ideally the frame accepts the same type of card as your camera so you can pop it into the frame to share the days results. If your card isn't supported you may be able to make it work using an adapter. The number of photos you can display is usually only limited by the number of photos that will fit on the card.
• Internal memory lets you store a permanent collection of your favorite photos in a frame so they remain playable when you change or remove the card. Software in the frame may reduce stored images to the frame's optimal size so more will fit in memory. (The original images remain unchanged). You can usually select which photos are moved into internal memory but some frames also store images there that have been fed to it by e-mail, RSS and other ways. The number of photos you can store in internal memory is determined by the frame's storage capacity.
• USB outlets on a frame let you connect it to a computer by cable. The frame may then appear on your computer as a hard drive so you can copy images to it.
• A phone line connection lets you plug a frame into a phone jack and it then uses an old-fashioned modem to dial up a Web site and download any photos that you or others have placed in the specified album. This is a great way for a family or group of friends to share photos among themselves. Monthly fees usually apply but this technology may be the best when you give a frame to someone who is clueless about computers. (Do you really want your grandmother and grandfather dealing with RSS feeds on a WiFi enabled frame?)
• Wireless capability lets you put a frame on your home or office network so it's just like any other drive. If you have a WiFi-enabled digital camera that is supported by the frame, you can download photos directly from the camera or even view photos on the frame as you take them. An optional network card may be required.
• E-mail feed lets you set-up a free e-mail account so the frame has a dedicated e-mail address. You (or anyone else) can then e-mail photos to the device.
• RSS (Really Simple Syndication) capability lets you download selected photos to a frame from a Web site such as Flicker or Google's Picasa Web Albums. To do this the photo sharing service supplies the RSS feed and the frame is the feed reader. RSS is discussed later in this chapter.
• Bluetooth support lets you transfer photos to a frame from any other bluetooth device such as a camera phone.

Displaying Slide Shows

Although many people just pop in a card with their latest photos, you can edit your photos on the computer and then transfer them to a frame. When copying them to a card there are usually requirements about filenames such as retaining the extension, and sometimes about the folder into which you copy them. Filenames can also be important if a frame displays images in alphabetically order.

Multimedia features let you display sound movies and accompany your slide show with background music, usually in the popular MP3 format.

A frame can display any content as long as it's in a supported format. For example, you can display a PowerPoint presentation by using PowerPoint's Save As > JPEG commands to save each slide as a separate JPEG file. You can then adjust the interval setting on the frame for an automated show or browse the slides manually with a remote control.

• Audio and video out connectors and cables let you display your show on another system such as a TV. If you play audio on the frame itself the quality of the built-in speakers is important.
• Supported file formats vary, so make sure the frame supports the image, video, or audio formats you plan on using. All frames display JPEG images and some also support PNG, BMP and TIFF. A few frames support common video formats such as MPEG-1, MPEG-2, MPEG-4, Motion JPEG, AVI, 3GP (video phone format) and the audio formats MP3 and WMA. Some frames have limits on file sizes and none support any of the existing RAW formats. Playing video files smoothly may require a high-speed card and even then you may be disappointed by the image and playback quality.
• Image management features let you rotate, copy, crop, and delete images. Some frames let you add masks and borders and apply special effects, perhaps to show a photo in sepia or black and white. Some also let you organize photos into albums or folders so you can select which set of images to display at any given time.
• Browse mode lets you scroll through images manually.
• Thumbnail view lets you see a number of images at the same time so you can quickly locate specific photos.
• Automatic slide show starts displaying photos as soon as you turn on the frame or insert a new card. A random shuffle setting saves you from having to see the same pictures each time you turn on the frame.
• Customizable slide shows let you specify which images are in a show and the order in which they appear.
• Settings let you specify transition effects and display times.

Other Features

• A remote control lets you change settings and control a slide show in progress. Zoom and pan buttons let you explore details in a photo.
• Software may let you add captions, sound, special effects , and transitions, set display times, and rotate images.
• Software upgrades can sometimes be downloaded from the manufacturer's Web site to upgrade your frame when improvements are made.
• A rechargeable battery on a few models gives you the choice of operating your frame cordlessly for a short time so you can pass it around for people to get a closer look.
• A built-in clock turns your frame on or off at times you select. Ideally you can set different times for weekdays and weekends. At least one frame (Philips) lets you specify a date, such as a birthday, when a specific photo will be displayed.