One Post was just not enough for this; here we discuss
some finer details into buying a camera…
Image stabilization (IS):
This is what keeps your photos from displaying camera shake. There are two physical types: in-camera sensor shift and in-lens optical. While they perform similarly, optical IS seems to work a little better while shooting video, but sensor-shift means that for interchangeable-lens models you don't have to wait for the manufacturer to put IS in the lens and the lenses will likely cost less and be a little smaller. Cheaper cameras may have electronic IS, which uses a combination of fast shutter speed and higher ISO sensitivities to help with motion blur. Unfortunately, this increases image noise and is less effective in low lighting. EIS does make sense as a complement to physical stabilization, since it can respond faster when shooting video.
This is what keeps your photos from displaying camera shake. There are two physical types: in-camera sensor shift and in-lens optical. While they perform similarly, optical IS seems to work a little better while shooting video, but sensor-shift means that for interchangeable-lens models you don't have to wait for the manufacturer to put IS in the lens and the lenses will likely cost less and be a little smaller. Cheaper cameras may have electronic IS, which uses a combination of fast shutter speed and higher ISO sensitivities to help with motion blur. Unfortunately, this increases image noise and is less effective in low lighting. EIS does make sense as a complement to physical stabilization, since it can respond faster when shooting video.
Battery life and type:
Most cameras use lithium ion rechargeable battery packs. While they offer greater battery life than readily available AA -size batteries, they are generally designed for a specific make or model of camera. There are models using AA batteries, but they're usually lower-end compacts and larger mega-zoom cameras. When buying a camera, check out how many shots its battery has been rated for, a specification that has been standardized by CIPA.
Most cameras use lithium ion rechargeable battery packs. While they offer greater battery life than readily available AA -size batteries, they are generally designed for a specific make or model of camera. There are models using AA batteries, but they're usually lower-end compacts and larger mega-zoom cameras. When buying a camera, check out how many shots its battery has been rated for, a specification that has been standardized by CIPA.
Burst/continuous shooting rate:
A measure of the number of frames per second a camera can capture, this spec can get quite confusing. Optimally, you want a high frame rate, at full resolution, with autofocus and auto-exposure, for a reasonable number of frames. In order to report a high frame rate, the most common spec, companies play fast and loose with the other variables; so, for example, they'll say the camera does 10 frames per second (fps) -- but that's for 10 frames (1 second) with exposure and autofocus fixed at the first frame, while the usable burst rate will be closer to 5fps.
A measure of the number of frames per second a camera can capture, this spec can get quite confusing. Optimally, you want a high frame rate, at full resolution, with autofocus and auto-exposure, for a reasonable number of frames. In order to report a high frame rate, the most common spec, companies play fast and loose with the other variables; so, for example, they'll say the camera does 10 frames per second (fps) -- but that's for 10 frames (1 second) with exposure and autofocus fixed at the first frame, while the usable burst rate will be closer to 5fps.
Video:
For typical vacation videos or videos of the kids, you want 1080/30p -- "1080" refers to 1,920x1,080-pixel resolution, also referred to as Full HD, while "30p" stands for 30fps progressive video. These days, you should stay away from 60i -- 60 fps interlaced -- as it has more visible artifacts than even 24p. If a camera offers a frame rate greater than 60fps, that lets you create slow-motion videos. As for codecs, the algorithms which compress and decompress the video, look for a real codec like H.264, AVCHD or XAVC, which are subsets of MPEG-4, rather than Motion JPEG. The actual video files have formats like MOV (QuickTime), AVI (Microsoft Audio/Video Interleave), MP4 and MTS (AVCHD). Video recording also has a bit rate, the amount of data it encodes per second of video; for this, higher is generally better. Because AVCHD is really a playback specification, it's a lot less flexible with respect to available bit rates than H.264 MPEG-4. We're also starting to see more support for 4K capture in cameras, though the best thing about these currently is that the extra processing power it requires means the cameras can usually support higher-bit-rate HD video.
For typical vacation videos or videos of the kids, you want 1080/30p -- "1080" refers to 1,920x1,080-pixel resolution, also referred to as Full HD, while "30p" stands for 30fps progressive video. These days, you should stay away from 60i -- 60 fps interlaced -- as it has more visible artifacts than even 24p. If a camera offers a frame rate greater than 60fps, that lets you create slow-motion videos. As for codecs, the algorithms which compress and decompress the video, look for a real codec like H.264, AVCHD or XAVC, which are subsets of MPEG-4, rather than Motion JPEG. The actual video files have formats like MOV (QuickTime), AVI (Microsoft Audio/Video Interleave), MP4 and MTS (AVCHD). Video recording also has a bit rate, the amount of data it encodes per second of video; for this, higher is generally better. Because AVCHD is really a playback specification, it's a lot less flexible with respect to available bit rates than H.264 MPEG-4. We're also starting to see more support for 4K capture in cameras, though the best thing about these currently is that the extra processing power it requires means the cameras can usually support higher-bit-rate HD video.
Some Other Very Important Features:
GPS:
If you love knowing exactly where you were when you took a photo, you'll want a camera with a built-in GPS (global positioning system) receiver. Typically found in rugged or higher-end cameras (add-on receivers are also available for some ILC and dSLR cameras), the GPS receiver uses satellite positioning to tag your pictures with location data. This location data can be read by software as well as photo-sharing sites to map where the photos were taken. Depending on the camera's capabilities, the GPS may also be used to tag photos with landmark information, set the camera's clock to local time, and track your path on a map as you shoot or even help with basic navigation on foot. The biggest downside is that it will drain your battery faster as it has to be left on so it can continue to update your location. It also won't work indoors or, in rugged cameras, underwater. GPS will add to the cost of the camera, too.
If you love knowing exactly where you were when you took a photo, you'll want a camera with a built-in GPS (global positioning system) receiver. Typically found in rugged or higher-end cameras (add-on receivers are also available for some ILC and dSLR cameras), the GPS receiver uses satellite positioning to tag your pictures with location data. This location data can be read by software as well as photo-sharing sites to map where the photos were taken. Depending on the camera's capabilities, the GPS may also be used to tag photos with landmark information, set the camera's clock to local time, and track your path on a map as you shoot or even help with basic navigation on foot. The biggest downside is that it will drain your battery faster as it has to be left on so it can continue to update your location. It also won't work indoors or, in rugged cameras, underwater. GPS will add to the cost of the camera, too.
One last note: Though some models state that they tag
video with location information, the data is attached to the video as a
separate file instead of being embedded as it is with photos. Generally this
means the location information can only be viewed if the videos are played
directly from the camera or with bundled software.
Wi-Fi:
The most popular use for Wi-Fi connectivity is wirelessly transferring photos and videos off the camera, but many models can back up straight to cloud services or networked computers as well as connect directly to a mobile device, so you can view, transfer and edit shots, and then upload to sharing sites over your device's mobile broadband. Sony has gone to the extreme and basically created cameras without LCDs -- the QX series -- that are designed to be operated over Wi-Fi. Some models use Wi-Fi to remotely control the camera, too, using your mobile device's display as a viewfinder. It can also be used to piggyback on your smartphone's GPS receiver for tagging photos with location data. What this means is you can get things your smartphone's camera can't offer (such as better photo and video quality, a zoom lens and more control) and still share on the go.
The most popular use for Wi-Fi connectivity is wirelessly transferring photos and videos off the camera, but many models can back up straight to cloud services or networked computers as well as connect directly to a mobile device, so you can view, transfer and edit shots, and then upload to sharing sites over your device's mobile broadband. Sony has gone to the extreme and basically created cameras without LCDs -- the QX series -- that are designed to be operated over Wi-Fi. Some models use Wi-Fi to remotely control the camera, too, using your mobile device's display as a viewfinder. It can also be used to piggyback on your smartphone's GPS receiver for tagging photos with location data. What this means is you can get things your smartphone's camera can't offer (such as better photo and video quality, a zoom lens and more control) and still share on the go.
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