Fresnel Lenses

[Vin047]

So i've been doing a lot of reading over the past few weeks about 3D and finding it very interesting!

The major issue for me is that i (and most of my family) already invested in LCD and so not really looking to buy 3D TV's or 3D Monitors yet. I've been searching around for possible (perhaps diy) ways of displaying 3D with 2D LCD's. Naturally the most obvious is with anaglyph, and I probably will use that for now, but just exploring various alternatives.

I read on some various sites (including this one i think) that people used to use fresnel lenses attached to CRT monitors to get a 3D effect. Would it not be possible to get a large fresnel lense and place it in front of an LCD to achieve a 3D effect? I realise it wont be as good as using shutter glasses or new monitors etc but from what I read it does a pretty amazing job nonetheless right?

Would also like to clarify what the cons of this method would be and if you think its a worthwhile investment. There are 3 main LCD's id like to get into 3D and their sizes are 18.4", 26" and 52".

Any info appreciated!

[Likay]

I don't think fresnels (circular prismas) can be used to make it possible to view 3d. They only make the image bigger.
However: They work in a similar way as lenticular (vertical prismas) lenses which is used for some autostereoscopic displays. The nag is that all the lenticular lenses has to match the displays pixels and the result is a certain very few "hotspots" where 3d is visible and somewhat correct. The chance of success is vanishing small by just trying to make these matches yourself.

[cybereality]

Fresnel lenses act to magnify the image and can create a kind of "surround view" if you sit close enough to the lens. It is not really 3D and thus not really comparable to a stereoscopic image. It is, however, an interesting effect albeit something that is more suited toward experimentation than any real practical use. Its certainly not a substitute for a 3D monitor. If you are on a budget or won't replace your existing monitors than anaglyph is about the best you can do. I recommend the Pro-Ana glasses.

[Vin047]

hmmm i see. so what size of lenses do I aim for? (Same size of monitor/screen, larger, smaller?) might be interesting to see what its like.

but yh, for actual 3D i'll probably stick with anaglyph (I wonder what it looks like if you use both at same time?? I assume u can?)


with regards to the glasses I was thinking of getting something like these:

http://cgi.ebay.co.uk/ws/eBayISAPI.dll? ... 200wt_1165" onclick="window.open(this.href);return false;

http://cgi.ebay.co.uk/ws/eBayISAPI.dll? ... 262wt_1165" onclick="window.open(this.href);return false;

cheap I know (and so probably not amazing quality) but should suffice right? The 2nd one is slightly more expensive than the 1st, the only reason I can think of is the 2nd one is more curved, does this result in better image quality?


Actually I like the pro-ana too but a little wary of the price since I want to buy around 10 glasses (for use with the family). Does the pro-ana have equal 3D effect to regular red/cyan? What I mean is, I read about anachrome and pro-view glasses etc which give various "improvements" to the picture quality, but from what i've read these come at a cost of a more subtle 3D effect. Is this is also true with pro-ana? or does pro-ana have best of both worlds? (equal 3D effect to regular red/cyan but no ghosting) if thats the case I may be willing to invest in them instead.

Thanks for the help so far guys!

[cybereality]

Well the Pro-Anas seem to be the best overall, at least with my computer monitor (Zalman Trimon). Both the Pro-View and Anachrome are also good glasses and work better on some content. For example, I find when playing games with the iz3D driver the Pro-Ana have the least ghosting. Pro-View has the best colors and Anachrome is somewhere inbetween. On my living room HDTV for Xbox content (specifically Invincible Tiger) the Anachrome seem to work out better with less ghosting and retinal rivalry, then the Pro-Ana, then the Pro-View. But in general the difference is not huge between these glasses and even the generic paper ones. So if you are trying to save money those generic glasses will probably be fine.

[Vin047]

ok thanks cybereality

any advice on what fresnel lense size I should get for a 18.4" screen?

[cybereality]

The fresnel should be the same size as the screen.

[Vin047]

ok thanks likay and cybereality for your help!