Active Shutter v Passive 3D Glasses
I’ve just got back from the store where I’ve been checking out how polarized 3D glasses (sometimes called passive 3D glasses) stack up against active shutter 3D glasses. Now this is potentially a big issue if you’re thinking about upgrading to 3D TV, so I thought I’d get up to speed on the issue so I could tell you all about it! Let me tell you about Active Shutter v Polarized 3D Glasses!
3D TV Images are a Trick!
The first thing you need to understand is that 3D TV images are simply a trick played on your brain by the technology. Remember the actual screen you are watching is only 2 dimensional…so to see a 3D image the screen and the glasses literally trick your brain into seeing a 3 dimensional image. How cool is that?
The second thing you need to know is that if you want to use polarized 3D glasses…you will need a 3D TV that is designated “cinema” as it is only these LED TV sets that provide the images in a way that can be used by the polarized glasses. LG have been incredibly quick to “jump” on this technology and their LGxxLW6500 range provides great images for use with polarized glasses…I’m sure the others will follow!
Anyway, back to the images produced on the screen. If you have watched a 3D TV without the glasses (come on admit it, you’ve tried it)…you’ll know that there is a split image shown on the screen. This is because to trick the brain into thinking it’s seeing a 3D image two different (actual) images are needed. What you see without the glasses is the two images one transposed over the other, but slightly offset.
How Active Shutter 3D Glasses Work
The active shutter glasses very quickly flick each different lens (so each of your eyes) on and off very quickly thereby tricking your brain into seeing the two images merged as one image with the 3 dimensional depth.
That’s great but there are problems with active shutter glasses. The first and main one being they are expensive! Secondly they need batteries and with some models you cannot actually change the batteries and so when they run out…you have to buy new glasses – ouch!
From a technical viewpoint sometimes the timing of the opening and shutting of the lenses doesn’t quite “time” with the images on screen and this is one cause of crosstalk (3D image blur) – although this is not the only cause. Finally active shutter glasses are not overly comfortable and if you already wear spectacles, they are downright uncomfortable.
Now if I’m honest that all sounds a bit like a “hatchet job” on active shutter glasses…it’s not meant to be, although I have been a bit of a crusader on behalf of spectacle wearers the world over :>) I have spent many happy (if slightly uncomfortable) hours watching 3D TV through active shutter glasses.
So, what do I think of polarized glasses after testing them earlier today?
Polarized 3D Glasses
Well, firstly, in my opinion, they do not allow you to go to such a wide angle and retain perfect 3D – although I have seen videos online and listened to salesmen who say they are better at retaining the 3D image at wide and varying angles. LG will tell you that “you don’t have to sit up straight” to get a perfect 3D image anymore? Not sure about this.
The sales puff will also tell you that polarized glasses reduce crosstalk and there is far less image blur. Again, I really didn’t see a difference.
One thing that polarized glasses definitely win on is that sometimes you can see the “blur” of the shutters working on active shutter glasses. It’s only out of the corner of your eye, but sometimes you just “catch” it and it is a distraction. Because both lenses are permanently open on polarized glasses this issue is totally resolved.
Passive 3D Glasses Are More Comfortable
And, finally polarized glasses, because they don’t include the electronics to make the shutters open and close, are much lighter, far less cumbersome and therefore much more comfortable. And, as I am writing this, I have just been told that clip ons will be available soon – manna from heaven! This is a “biggie” for people (like me) who already wear glasses and don’t get on with contact lenses.
Oh, yes, and because of this, they are much cheaper! Yippee. This is why you are now seeing the main players giving away 4 or 8 pairs of glasses with new “cinema” 3D TV sets.
So, to sum up, I believe this is a good advance in 3D technology. If I am really honest I can’t see a lot of difference in the 3D image produced, but I do see major advantages on cost and comfort with polarized 3D glasses. So, active shutter v polarized 3D glasses? Well, if you already have active shutter glasses, you are certainly not missing out. If you’re considering 3D then certainly take into account the factors I have mentioned here. Good luck and why not post a comment and let us know about your experience with 3D glasses, be they polarized or active shutter.
Active Shutter 3D Glasses
Polarized 3D Glasses
Passive 3D Gasses