Posted by: Laura
Active – The first major different is in the glasses, as Active 3D requires the use of powered glasses. Whilst early models required the use of batteries, the vast majority of modern glasses will use rechargeable cells, much like your smartphones or tablets. Why do the glasses need power though? You might ask? Essentially the glasses (which are also referred to as 'Active Shutter' glasses) shutter either the left or right lens so that data meant for your left eye is stopped from reaching your right eye and vice-versa.
Passive – Passive 3D is the most common form of 3D, and the 3D you'll have been accustomed to from visits to the cinema. In fact, you'll actually be able to use 3D glasses from the cinema with your own set at home (yes those flimsy plastic things that set you back less than a pack of chewing gum). The primary difference in the way Passive 3D works is that the glasses themselves don't actually do anything. These glasses work in much the same manner as the old paper 3D glasses of yore, creating the illusion of 3D by having one lens focus on the 'odd' lines of the screen and the other focus on the 'even' lines. In the cinema, this effect is achieved by using 2 projectors, however with TV screens, half the pixels are used to display the left image and the other half are used to display the right image. This means that without the glasses the screen looks relatively normal, only a little more 'fuzzy'. With Active 3D, viewing the screen sans glasses, it would appear as if you're watching two duplicates of the same image, with the screen split down the middle.
Pros and Cons
• You receive the image at the intended resolution as you are seeing the full screen independently with both eyes. This means the image is far more accurate and precise, perfect for gaming.
• Able to see FULL HD 3D (1080p) at 60fps.
• Twice the vertical resolution of passive 3D.
• Some wearers claim that the glasses are a little bulky and uncomfortable. This is because they have to be large enough to house a power source.
• Active 3D glasses are significantly more expensive than passive glasses, this means that equipping your entire family with them could prove incredibly costly.
• The shutter effect of active 3D glasses can make certain viewers fells nauseous and it's been reported that extended use can lead to headaches and eye strain. Unless they remake Das Boot in 3D though, you shouldn't have a problem watching for a couple of hours at a time (the length of an average movie) as long as you remember to take occasional breaks.
• Occasional flickering and crosstalk.
• Reduced brightness.
• Incredibly cheap glasses, and in fact, cheaper overall. The glasses are also (generally) far more comfortable to wear.
• More comfortable for your eyes and less likely to cause nausea.
• The image is typically brighter with passive 3D, as there is more light reaching your eyes.
• You'll most likely already be accustomed to passive 3D, unless you haven't been to the cinema in the last decade of course!
• Half the vertical resolution of Active, which could irritate real purists.
• Less precision than active 3D, which means it's not as suitable for gamers.
Which to Choose?
Ultimately this depends very much on the individual. Active 3D offers the sharpest, most precise and immersive experience, but some people just can't enjoy it and can't make peace with the price. Some have also complained that their brains can “sense” something isn't right and it makes using the glasses for any significant length of time incredibly uncomfortable. As this is the case, your best bet is to take a trip to your local electronics store and ask if you can try out the displays for yourself. In general though; if you require expert precision (for gaming especially) then Active is the way to go, but for most casual viewers, Passive will more than do the job!
Glasses-free 3D is still years off being a completely viable option, though it is definitely “The dream” for all technology companies. The technology is there, but it's simply not affordable at the moment, and whilst the 3DS achieves the effect, it's far from perfect. So for now, if you want to immerse yourself in the world of 3D, you'll be donning your glasses for the foreseeable future.