Digital Photography For Dummies. Julie Adair KingЧитать онлайн книгу.
increasing the ISO setting, which makes the camera more sensitive to light. When the camera is at a higher ISO, you can use a faster shutter speed, which means that the length of time you need to hold the camera still is reduced. Unfortunately, a higher ISO often brings the unwanted side effect of image noise, as discussed in the earlier section “High ISO performance (low-light picture quality).”
Even the best possible stabilization system can’t work miracles; you still need a tripod for very long exposures. But you can expect to get a steady shot at shutter speeds slower than what you can enjoy without stabilization. How much slower depends on the capabilities of the camera or lens as well as your ability to hold the camera still.
Long story short (too late, you say?): This is one camera feature that I highly recommend to photographers of any level.
Viewfinder: Optical or electronic?
But not all viewfinders work the same way, and because this component plays a critical role in your camera use, it's worth understanding the differences. Here's a look at your options:
Optical viewfinders
This term is used to describe a standard viewfinder — the kind that's been used for a long time in both film and digital cameras. Optical viewfinders come in two forms:
TTL (through-the-lens): The display is created by light coming directly through the lens.
Non-TTL: For technical reasons I won’t bore you with, a TTL lens requires a larger, bulkier camera design. As an alternative, some cameras have non-TTL viewfinders, which simply means that the placement of the viewfinder is such that it has a slightly different angle on the scene than the lens. This results in parallax error: The viewfinder doesn't show exactly what the lens will capture, making it difficult to precisely frame a photo.To help solve the problem, most cameras include framing marks in the viewfinder to guide you; when camera shopping, be sure the framing marks are easy to see. And note that not all viewfinders of this type are created equal — the amount of parallax error varies from camera to camera, so do your research.
Electronic viewfinders (EVFs)
With an electronic viewfinder (EVF), the camera sends the live feed that's normally displayed on the camera monitor to the viewfinder, and because the monitor shows the same area as the lens, this viewfinder option offers the same improvement in accuracy that you get with a TTL optical viewfinder. But the EVF system has two other benefits: First, you can not only use the viewfinder to compose your subject, but also see everything normally displayed on the camera monitor. You can review your photos through the viewfinder, for example, and see camera menus. I love these features when I'm shooting in bright sunlight. Instead of having to look for a shady spot where I can clearly see what the monitor is displaying, I simply look at the viewfinder display. However, EVF displays vary in display quality, size, and performance, so this is one component you should test in person.
Video-recording capabilities
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.
Memory-card features
Instead of recording images on film, digital cameras store picture data on removable memory cards. Most cameras can hold only one card at a time, but some have two card slots. This feature is great because you can configure the two cards to perform different storage functions. You can put all your Raw files on one card, for example, and JPEG files on the other. Or you can send all files to both cards so that if one fails, the other provides a safety net.
Another thing to know about memory cards is that they vary in terms of capacity and in how fast they can record data. Larger cards hold more pictures and videos, and faster cards enable you to capture more pictures per second and record smoother videos. But not all cameras can take advantage of the highest-capacity, fastest cards. I won’t bore you here with an explanation of card capacity and speed specs (I save that for Chapter 2); for now, just know that if you do a lot of fast-action photography or video recording, this is a camera feature that matters.
Convenience features
No matter what category of photographer you consider yourself, I rank the following features as not critical, but nice to have: