using a lens mount. Figure 1-4 shows a close-up of the mount on a Sony dSLR. It’s pretty large, and has to be made of metal to stand up to the stresses of mounting different sized lenses. Here is a quick summary of the lens mounts that the top manufacturers use:
❯❯ Nikon uses the F-mount, which is standard on both its cropped (DX format) and full-frame (FX format) dSLRs. Nikon also uses the DX classification to identify lenses that are optimized to work on cropped-frame, DX-format camera bodies. Lenses without the DX identifier are compatible with DX and FX-format camera bodies. As a bonus, Nikon’s FX-format camera bodies can use DX-format lenses in a special “DX crop” mode. This mode uses the area in the center of the image sensor and results in a smaller, cropped photo.
❯❯ Canon dSLRs use the EF lens mount on all its cropped and full-frame cameras. Canon uses the EF-S lens designation to identify lenses that are only compatible with cropped-frame Canon cameras. All Canon dSLRs can mount EF lenses. Only cropped-frame dSLRs can mount EF-S lenses.
❯❯ Sony uses the Alpha mount or A-mount (refer to Figure 1-4). Of note, DT lenses are compatible with cropped and full-frame bodies, but images are recorded cropped on the latter. Sony E-mount cameras such as the A7R and A6300 have dSLR-sized sensors without the mirror or optical viewfinder. A-mount SLR lenses can attach to E-mount cameras with a special adapter.
❯❯ Pentax dSLRs use the K-mount. There are several K-mount sub-types that feature different contacts and autofocus drive capabilities. In addition, adapters are available to mount old screw mount Pentax lenses to K-mount cameras.
❯❯ Olympus dSLRs use the Four Thirds mount while its newer mirrorless interchangeable lens cameras use the Micro Four Thirds mount. Note that you can attach Four Thirds lenses to a Micro Four Thirds body with the proper adapter, but not vice versa.
FIGURE 1-4: The lens mount determines what lenses are compatible with your camera.
Mirror and viewfinder type
Digital SLRs have a reflex mirror that sits in front of the closed shutter and covered image sensor. Its purpose is to reflect light that comes into the camera through the lens up and into the viewfinder (among other things). This is how you view the scene, and how the camera meters the light and focuses. When you press the shutter button, the mirror moves (this is what reflex means) quickly up and out of the way, allowing light to expose the sensor. When the exposure is over, it moves back into the down position.
Digital SLTs (single-lens translucent) cameras do not have a moveable mirror. They have a semi-transparent, or translucent, mirror that stays put when you take the photo. The mirror allows some light to shine through it and onto the image sensor while bouncing the rest up into the camera's viewfinder (or into another sensor that drives the electronic viewfinder). For most purposes, dSLTs look and function just like dSLRs.
Typical dSLR viewfinders are optical. You look through a prism that directs light from the reflex mirror to your eye. They work whether the camera is on or off.
Some cameras (especially dSLTs and mirrorless cameras) now use electronic viewfinders to display information. Sony's electronic viewfinders, for example, are small, high-resolution organic light-emitting diode (OLED) monitors. This type of viewfinder combines the functionality of a standard viewfinder with the LCD monitor on the back of the camera. Because you’re looking at a monitor, anything that can be displayed on the back of your camera can also be shown to you in the viewfinder. You can compose and frame the scene normally, view photos during playback, see the camera's shooting display, and use the menu system – all without taking your eye away from the viewfinder. Truly awesome.
Figure 1-5 shows the electronic viewfinder of another Sony camera. This particular model extends outward from the body of the camera a bit. Optical viewfinders don’t need as much space, and will appear flush with the body even on small cameras.
FIGURE 1-5: Whether optical or electrical, the viewfinder enables you to see through the lens.
Lenses
You can buy most dSLRs bundled with something called a kit lens. While they are not typically top-of-the-line lenses, kit lenses are decent and have enough versatility for most amateur photographers. Kits are designed to get you started with a good lens without breaking the bank.
Currently, many consumer kit lenses are standard 18-55mm zoom lenses. Depending on the camera, you may have the option of choosing different kit lenses. Very often, these alternate lenses are a step up in quality and price, and have different focal length ranges.
Turn to Book 1, Chapter 3 to learn more about lenses. You can also turn to Book 2, which covers a number of different lens types in depth.
Wrapping it up
Returning to the two cameras I mentioned in the introduction to this section, you should now understand that the Nikon D3300 is an F-mount, cropped-body dSLR from Nikon with an APS-C sized sensor. It is compatible with Nikon DX and FX-format lenses and captures photos that are 24.2 megapixels in size. It comes with an 18-55mm kit lens. The Sony A99 is full-frame A-mount dSLT. The photos it captures are 24.3 megapixels in size. It features a fixed translucent mirror along with an electronic viewfinder. The A99 is not generally sold as a kit so no lens information is listed.
Pricing Digital SLRs
Camera manufacturers design and create dSLRs for different audiences. This enables them to meet the needs of a wide range of people and sell more cameras. It gives you the freedom to choose a camera with the features, capabilities, and price that you want.
The following sections organize these market segments into three broad categories, each featuring cameras designed and priced to appeal to that audience. If you shop around, you’ll see that Canon and Nikon have more than one dSLR in each category and are constantly updating their lineup. Not all camera manufacturers compete so heavily across the board.
Consumer dSLRs
Consumer dSLRs are great cameras for the average person. They range from entry-level models priced under $750 (see Figure 1-6) to more advanced consumer-level models that cost near $1,000. At this level, cameras are often sold as kits. This means that a basic zoom lens is sold with the camera body. The lens increases the overall cost slightly compared to buying the body only, but most consumers like the convenience of having everything they need to get started in one box. At this level, all dSLRs are made from polycarbonate and their image sensors are cropped-frame.
FIGURE 1-6: The Nikon D3200 is a good example of an entry-level consumer dSLR.
Compared to more expensive cameras, consumer dSLRs are less expensive,
