This discussion is limited to Consumer-Grade camcorders. Professional camcorders that achieve very high quality recordings are beyond the scope of this discussion... afterall, this website is about cruise and vacation photography (and yes, I have seen a few cruse passengers lugging around pro video gear).
These days, with so many cameras having a video function, is there really any reason to buy a CamCorder (video camera) anymore?
...you bet there is.
First, realize that a camera is not a camcorder. All cameras are optimized for taking photos, not video. Video is a secondary function. For the most part, using a camera for video is overkill. Even 1080p video only takes around 2.1Megapixels, so using that 16Megapixel camera for video use is inefficient at best, and a bad compromise at worst.
There are several disadvantages to using a camera for a video recorder:
- Limited recording time. All cameras with the primary purpose of taking photos are limited to video recording times of 29 minutes - 59 seconds. This limit is set by the WTO/ITA (World Trade Organization/Information Technology Agreement), as CamCorders - those cameras primarly intended for video, are tariffed at a higher rate. So to preserve the VAT (Value Added Tax) of some countries, all cameras are limited to less than 30 minutes. CamCorders do not have this limitation - as they are subject to the VAT.
- Sensor overheating. Since the digital sensor in a camera is optimized for photography, they tend to heat up during video use. Especially for the lower expensive cameras, they may only allow recording for just a few minutes before the sensor overheats and shuts the camera down. In the worst examples, the video feature in some inexpensive camers may shut down after only a few seconds.
Needless to say, with this kind of performance, the 30 minute WTO/ITA recording limit is a moot point - but camera manufacturers are improving heat dissipation - and at some point, may hit the 30 minute brick wall. However, there has been some movement by various governments to remove this limitation from the trade agreement - but we are not there yet.
- Pixel Mapping. Here is where it gets deep. You should realize that when it comes to video, virtually all cameras are overkill. As previously stated, Full HD requies 2.1Mp, so how does a 16Mp camera sensor get turned into a 2.1Mp sensor? There are three techniques that can be used; "Pixel skipping", "cropping", and what I like to call "Oversampling".
Pixel skipping, which is the worst solution is also the most popular. Simply put, entire rows of pixels are skipped when the sensor is read. This means 14Mp out of a 16Mp sensor used for video is simply discarded. This is necessary as the camera's processor simply does not have the horespower to read every pixel and blend the results. The higher the pixel count of a sensor, the more likely this technique is used. Even DSLRs tend to use this technique.
Cropping as you might imagine is simply using the center portion of the sensor, either directly or at a manageable size by using oversampling. You will know if your camera does this if you see a focus shift from photos to video. However, I know of no cameras that currently employ such a process, although some camcorders may indeed use this technique.
Oversampling is where every pixel of the sensor is read, but then averaged into the result. I call this "oversampling" as it is reminiscant of how CD players sometimes read and average data. There are only a few cameras that have a manageable sensor - combined with the processing horsepower to accomplish this. The "Nikon 1" series of cameras were first to do this, followed by the Sony RX10 - which is why both of these cameras have incredible video capability.
Unfortunately, camera manufacturers do not tell you what technique they use to accomplish this mapping. However, the larger and more pixels a sensor has, the more likely it uses pixel skipping to acheve this goal. Camcorders may have the advantage here as they often to use smaller pixel density sensors, so they more likely use oversampling, cropping, or a combination of the two. The Sony Action Cam for instance masks a 16Mp sensor off to 11.6Mp, which is a sure sign of cropping, and may result in the ability to oversample the remaining sensor.
- Abbreviated features. It is quite typical that CamCorders have considerably more capability for video than cameras - including stereo mics, remote mic capability, video LED lighting, editing features and so on. Cameras tend to lack many of these features, but some items such as stereo mics and remote mic capability do exist on some higher end cameras.
- File format. Most cameras with a video function output format is MOV, which may also limit the length a movie can be. In contrast, most higher end CamCorders output format is AVCHD, which is optimized for video, and can typically record longer.
- Battery. Since CamCorders are more efficient at recording (don't tend to overheat the sensor), the battery usually lasts longer between recharges than do cameras.
- Ease of use. Many CamCorders have a single button that both turns the camera on and starts the recording. And there are typically fewer settings and buttons to contend with than the typical DSLR. Not eveyone wants to be a highly skilled photographer, and sometimes simpler is better.
So if CamCorders have all of these advantages, why even consider a camera for video?
- Convenience. Time and time again, consumers prefer convenience over quality. Whether this be the old VHS vs. Beta argument, CDs vs. Vinyl, or smartphones vs. cameras, consumers will chose convenience over quality over and over again. It is simply more convenient to carry a single camera than having to carry two - especially since some cameras (Nikon 1 for instance) can take a high quality photo during video recording.
- Access to lenses. Especially in the DSLR world with interchangeable lenses, high quality lenses can be used. And since these lenses also have manual focus and zoom capability, sophisticated setups such as "focus followers" can be employed. And since this is more-or-less a professional setup, the recording time limit is not an issue as such cameras typically record individual scenes lasting only a few seconds or minutes, and edited/spliced together in post processing.
- Cost. Obvously a single camera is less costly than owning two cameras.
These days, almost all cameras and video recorders will do 1080p Full HD. And the issue of which is better is a moving line... Some cameras are gaining sophistication in their video features. For instance, the tiny Nikon P330 compact camera has a true "Pause" function that most cameras as well as camcorders lack. The Pause function allows you to interrupt your video for a short period of time (changing scenes, waiting for a better shot, etc), without the camera creating a file for each time you pause it. This is very handy for the occasional video when the photographer does not want to have to assemble video snippets into a longer movie.
Some DSLRs also have articulated (swing out) LCD screens that can aid in video use. However, caution should be taken before purchasing such a camera as often the LCD screens result in a longer shutter delay. Shutter delay is a measurement of the time delay from depressing the shutter to when the photo is taken. A longer shutter delay means the camera may not be as good for sports and action photography. Therefore, articulated LCDs may actually be a disadvantage if your primary use of the DSLR is photography.
Other cameras, such as the Nikon 1 series actually have dual processors in the cameras. This allows you to take video while simultaneously snapping a photo. These cameras have a dedicated shutter button and video record button. This feature may be an advantage if you want both a lot of video and photos of your next vacation.
So which approach is better? Only you can decide that. I have provided you with the salient characteristics of each type of camera, and your photography vs. video needs will dictate whether you purchase a camera or a camcorder.