Originally Posted by Irishdoom
So there are many discussions on this board, that often devolve into battles of linked articles, about passive vs active in terms of true 1080p.
I don't care about that argument, and instead hope to see a discussion of the OTHER merits of Active vs Passive.
I currently have a Sony 40HX800 that I purchased about 2 years ago. It has a fabulous image both for 2D and 3D. I enjoy 3D when I get to watch it, but I rarely get that chance. The reason is myself and my wife have never found either of the active glasses types we've bought all that comfortable. I have 2 pairs of the run-of-the-mill Sony battery powered glasses that came with the 3D kit I bought with the TV. I also have 2 pairs of the Sony Playstation rechargeable glasses.
So there is definitely a part of me that wants passive 3D in my next set just because of the glasses.
But what are the other issues? Do you have to sit up and keep your head level with all 3D TVs? (My wife likes to lay down sometimes when we are watching movies, and the 3D seems to go bye bye.)
What are the 3D viewing angles like on passive vs active? One element of passive and its cheap glasses that is intriguing is being able to have many people experience it without needing 8 pairs of charged up glasses ready at all times.
With our current TV, eye level falls on the bottom half of the screen. I've heard some stuff about ghosting in passive if the TV is too high or too low. What's that all about?
Overall, what I'm most hoping for is a discussion about Active vs Passive minus the "true 1080p" arguments.
Without discussing true 1080p or not, ther eare still image quality issues with passive - the scanlines at anything less than 3x screen width I find very noticeable (others claim to not see them as close as 1x screenwidth so it's very much a personal thing) but even outside the range I can see the scanlines the image artifact they create is sometimes visible (think you can see the effect of moir furhter away than you can see the individual lines that make up moir). I find it most noticeable in the rim of a cup or glass. The rim tends to be a high contrast round shape with very defined but thin edges. This stresses the image artifacts introduced by the scanlines in that you can usually see rough seperation in the lip and if it pans around you see the lines crawl around the lip.
I find this very distracting and a big negative although many people I know claim they don't see it or only notice if looking for it. I think it has to do with the way I watch TV as I have trained y eyes to watch for quality issues, and once you do that you can't stop doing it.
As for horizontal alignment FPR works by putting an array of bars in front of the screen basically. If the bars are right in front of their light eliment, they block it out (in conjunction with the glasses) but as with anything in front of something else, whether it's truly in front of it or not depends on where you view it from.
In my experience being a little under center is best... I don't know if my screen is built funny or something but I swear 5-10 degrees below center gives less ghosting than dead center.
That said I have never found a 0 ghosting spot. It seems that even in the best spot, extreme scenes (ie big seperation and high contrast) will ghost in one eye or the other. Sometimes the left eye will ghost the top left ot the screen and the right eye will ghost the bottom right or some such combination. Moving up or down will help one eye while hurting the other.
Overall I find ghosting to be a very minor issue. When it happens it's noticeable, but it tends not to happen much (again pretty much high seperation high contrast areas).
The further back you sit the broader the acceptable view height becomes.
When lying down, as long as your eyes remain in the accetpable viewing range the 3D does kind of still exist... although as mentioned above it goes from horizontal seperation to vertical seperation. This is not how you perceive 3D normally as your eyes are not vertically offset, however I find it does still work to some extent... it looks weird at first and feels wrong but I can still determine depth while sideways. I have heard from others it still looks fine and 3D and they don't see any difference. Again it depends on the viewer.
The nice thing about passive is when you turn your head sideways the screen doesn't black out like it does on some active displays when the glasses polarization matches the displays... I believe passive is circular polarized which is much more orietnation friendly.
I don't understand how passive can have better depth... that doens't make sense from a logical perspective since depth is governed by the horizontal seperation of the images and neither passive nor active changes that.
Passive does appear brighter however I would argue that it lets more light through... passive glasses themselves block about 30% of visible light while active glasses will block close to 70% (while functioning).
This seems to give a huge benefit to passive however you have to remember passive glasses are blocking 50% of the display 100%... that means they are actulaly only letting through 50% of the light to begin with and then filtering that 50% by about 30%. So overall light thorugh is the same for active and passive...
The difference is the brightness of the light that does come thorugh with passive is brighter (ie the 50% of the lines on the screen that do come through are only 30% dimmed while with active you get all the lines of light but they are all dimmed 70%). I say this is analogous to looking at a large but somewhat dim bulb vs seeing a few bright small flashlights. While the total light output from both maybe the same, the small bright lights will look brighter.
There are a lot of pros and cons and neither is a sure winner. It's best to try them both yourself and prioritize.
If cheap, comfortable non charging glasses are a huge thing for you, passive is obviously a winner.
If resolution clarity and detail are paramount then active has an advantage.
Almost all other image quality aspects are subjective.
Originally Posted by rekbones
I do have a HD33 projector in my home theater that is of course active and it is a better picture then the passive in the theaters so for that reason I would have no interest in a passive projector.
I just try to clear this up when I can - the saying "passive is the technology they use in theaters" is very misleading. In theaters you wear passive glasses but the image is alternated in a very active manner.
In theaters the passie glasses do not block out alternating rows of resolution and in function it's very much an active display method - just the shutter is moved to the lense away from the eyes.