Читать книгу Digital Photography For Dummies - King Julie Adair, Julie Adair King - Страница 38

Most digital cameras can record video as well as still pictures. In this book, I don't provide much video-recording information, for two reasons. First, if all you're after is basic recording, there's not much to it: You press the Record button to start recording and press it again to stop. On the other hand, if you want to get serious about digital cinematography, you're probably after a lot more information than I have room to offer in this book.

That said, I realize that you may want a little guidance as far as knowing which video-related specs are most important, so the following list gives you an introduction:

  Video resolution (frame size): Just like photos, digital videos are created out of pixels, and the resolution, or frame size, indicates how many pixels are used to produce each frame of video. The highest resolution found on most cameras is 1920 x 1080, known as Full HD (high definition, as in HDTV); the second highest, 1280 x 720 pixels, which is Standard HD.Many cameras now also offer 4K video, which delivers approximately 4000 horizontal pixels and is designed for the hot (for now) new 4K displays.

 Progressive (p) versus interlaced (i): This spec has to do with the way that the video frames are created. Progressive is the more current technology and is considered better for most video-recording purposes.

 Frame rate: This value indicates how many frames the camera records per second, which affects the look of your movies:24 fps: The standard for motion pictures; gives videos a soft, movie-like look.25 fps: The standard for television broadcast in countries that follow the PAL video-signal standard, such as some European countries. It gives videos a slightly more “real-life” look.30 fps: Resulting in even crisper video, 30 fps is the broadcast standard for the United States and other countries that use the NTSC signal standard. It's the default setting for cameras bought in those countries, too.50 and 60 fps: These super-high frame rates are designed for capturing very fast action as well as for shooting footage that you want to play in slow motion. (More original frames delivers smoother slo-mo playback.)How about 50 versus 60? You’re back to the PAL versus NTSC question: 50 fps is a PAL standard, and 60 is an NTSC standard.120 fps or faster: A few cameras raise the frames per second bar even higher. Again, the purpose of this high frame rate is for creating slow-motion footage.

 Audio features: Built-in microphones on most cameras produce so-so audio quality and also often pick up and record noise from the camera’s autofocusing system. For better audio, some cameras allow you to attach an external microphone. If you’re a serious videographer, look for a model that enables you to attach headphones so you can monitor audio as you’re recording.

 Continuous autofocusing: Most new cameras can track focus during recording, a capability that was missing until a couple years ago. Of course, on interchangeable-lens cameras, you can forego autofocus and focus manually, but it takes practice to be able to adjust focus manually without creating noticeable camera movement.