wow! you were really fast! thank you! i'll try and post

thank you again =)

you were right! it is very close! it is not 3d yet, but it's the closest pattern i have printed =D thank you! I have one question: now i only have to try different patterns close to this one, right? how did you do that? you tried 17 px insted of 16? or what? I mean.. how do i print more patterns having this one?

PD: with the alignment test image i got blue-red (with your pattern) with the others i got red-blue so i guess it might be a little bit bigger... (your alignment test image is very useful) thank you a lot for all this =D i cant believe im having 3d in my monitor this week xD

You have to make a more complex pattern in order to fake a higher resolution. For example, you can have five 12 pixel lines and then one 13 pixel line. That would give you a barrier with the approximate width of 12.1666 pixels. The one you need is going to be close to that one (and it might be a good place to start). If you follow my tutorial I show how to create pattern files in Photoshop, its very easy.

well, couldn't he just scale it down slightly in photoshop's print properties? then it's all automagical, and he won't have to worry about 12/13 pixel lines and whatnot.

I got strange results when I tried using the Photoshop scaling, but this was also back with my 600dpi printer so maybe 1200dpi will handle this better.

Wow, this sounds a bit complicated! I think it would be great it it could be done to create 3d glasses for next to nothing though! With the emergence of 3d televisions now, it would be really great to save some money on creating the glasses yourself, but only if they are up to par. I'm hoping that glasses will go down in price in a few years as the technology becomes more common place.

i got better results with the new pattern (5x12,1x13), thanks, it still is small, but it's very close, because i got only one line, blue-red. And at the center of the pattern it is white (or black) But i cant see the 3d image... Is this normal? should i be able to see 3d images with this pattern?

Yeah, it is somewhat complicated. I am looking to find a method that is easier but I've just been busy. But I am not done with this, its an evolving project. If you are interested, I am actually sending out free 3D glasses. They are just the cheap paper red/cyan ones, but they work OK. Certainly a good option if you don't have a high-end 3D solution. Just PM me with your name/address and I will send them right out.


It is very difficult to get the perfect pattern. I might have printed over 50 tests just to get the right pattern for that video. So don't be discouraged if the first few are not right. Unless is is extremely close to the right size, then you are going to have trouble seeing in 3D. Also, try flipping the barrier around (so the printed size faces the monitor) and also try moving your head forward and back. That changes the way it looks. You will probably have to learn how to customize it yourself, as it takes a lot of trial and error.

Good Job Cyber

Unfortunately I have Transparency Film for Laser printer but I only have injet printers. I tried anyway but the ink make some sort of bubbles. I wanted to convert my old smartphone to a brand new stereo smartphone I'll have to buy special filter ^^

Yes, you must make sure you get the correct transparency film for your printer (inkjet or laser) and also read the instructions because you usually can only print on one specific side (usually the rough side) and may need to put it in the printer a specific way. Also, stay away from overhead transparencies, acetate transparencies, or anything else that doesn't specifically say its meant to be printed on by consumer inkjet or laser printers. Although other types may work, you might just waste your money if it doesn't print right.

Yes. I'll buy one of these tomorrow.

Did you try to madke a filter for your smartphone (if you own one) ? It could be interesting. Well you'll have to make your own software to watch your images/movies, but it could be really fun !

Yes, I am thinking about it. But, like you said, it would also required writing custom software so it is a more involved project.

On a smartphone you can simply import photos and videos in vertical interlaced mode, it's not interactive but that's a good start to evaluate the technology. If you own an iPhone/iPod you can also directly buy the parallax barrier from GRilli3D without having to print one yourself, they also have images and videos in interlaced format on their site.

I can help you with that.

Fredz> thanks for the information. But I don't have any Apple product

I managed to print my barrier for my smartphone ... It doesn't work :'(

If I move my eyes around my screen, there is some change but eache eye seems to view black and white line.

I'll have to print a new barrier !

I just noticed that if you search for "Parallax Barrier" on YouTube, a total of 11 of my test videos come up on the first page. The main $5 video is the first one, followed by the last big test I did in 2009. Out of the top 10, 5 are from my DIY solution. If you do the same search on Google 2 of my videos are featured for the video widget. Pretty impressive if you ask me. Though I am not so sure how many people search for the words "parallax barrier". Do you guys have any ideas for keywords I can use for my next video? I probably want to do something involving the Nintendo 3DS, since that will surely be popular in the coming months. Any other tips on how to improve the quality of the video would be helpful as well.

I think an head-tracking SW could solve this issue.



Could a fotography of the screen with a ruler placed on it help to determine parameters to create a suitable parallax barrier for remote users?
The user could also place on its screen a small, generic parallax barrier implementing different parameters, to be used as a reference by who will actually create the final p. barrier.

Yeah, something like that could help, but you have to realize even a mm of inaccuracy can destroy the effect. So it is almost impossible to do this remotely (I would need the monitor in my hands to test). I still have some plans to make a product out of this, but I have to figure some things out first. I will probably just end up buying a bunch of cheap monitors to test with. So I can support all the popular models. Not sure when this will happen, but hopefully sooner rather than later.

This is a fantastic project, actually I found this site via Youtube, searching Parallax Barrier!

I'm amazed how well its worked out, has anyone tried this on an iPhone? if so please email me saj_12@hotmail.co.uk

You can buy a parallax barrier specifically designed for the iPhone here :
http://grilli3d.com/

Hm, is there no way to create a "Parallax Barrier Creator Tool", where you input your LCD and printer geometry (maybe with tests), then print out some test patterns with different sub-mm adjustments, etc., etc. until the perfect one is found?

Yes, that is possible. Some members actually created tools like that (posted on the past 2 pages maybe). I didn't verify them, but they might prove helpful to you.

Ah, found it. Thank you!

I just made an online calculator for calculating the document and barrier widths, based on the supplied variables.
http://tinyurl.com/3we38kq

cybereality, could you try to make some sort of guide around this? Basically you'd create a photoshop document at your printer's DPI, supply your screen height and this calculated width, and then fill it with an interlace pattern where the number of white columns would be the same as your horizontal resolution, and black columns the same PLUS ONE, so the first and last columns are both black. I have no idea of how you could do this, apart from drawing every line manually which is probably out of the question.

I've included the width of the barriers/gaps in pixels, don't know if that helps or not.

My original version actually used a Photoshop script that would create the barrier for you. Later I ended up doing it manually, just to have a little more control, but I could easily update the script. Just been really busy lately. I want to create a new tutorial that is much easier to do. I think the method I used is just too confusing for anyone to follow.

Nice tutorial... i will try to build this. I have a Notebook Acer 7720G with maximum resolution of 1920x1200 pixel and hope it will work. Too bad it has the downside of cutting the resolution ingame into half but it seems all 3d-solutions has a problem of some kind at the moment.

I have a laserprinter with 1200x600 dpi maximum but it can only print maximum A4 but I will try it first with it.
At ebay i found transparent film coming from a business wind-up and so I bought 200 sheets for 10,20Euro. Cheap I think.

I was wondering what transparent tape is clear enough to see through clearly. I tested one at a window and... no good result. So I asked and the tape to look for is Tesa or Scotch "Crystal clear"... this tape is not the normal transparent tape so I was told... so I bought a pack with the scotch version and will see how it goes with it...

At last I bought a steel rule. Normally used by craftsmans but I bought it to use it together with a cutter. I hope to get a clear cut with this setting because I dont have a A3-Printer.

Lets see what I can get with this...

I was wondering what kind of printer makes the sharpest edge. I thought it should be a laser printer but you wrote the laser wasnt very good... So that means dpi is everything? I thought the ink wouldnt make such a good edge because the ink wouldnt remain strictly at his place... what about plotter? Or other techniques if any?

If the result isnt very good I will look after canon pixma... they have printers that print up to 9600x2400dpi in black and white. And the ones that can handle A4 but no A3 are sold for 40Euros if they are used. So this would be my next move I think when the result isnt pleasing.

Is the image darker with a parallax barrier because of the black? If so... wouldnt it be possible to use a light color next to white? White itself wouldnt be possible I think. But the color would block the pixle the same way I think. And its often the case that printers can print higher resolutions in color than in black and white.

What Im wondering is how to find out the pixel pitch? I cant find it for my notebook...

How about the difference between the parallax barrier and the pixel? Its not taken into account in all formulas except the javasoftware. But it looks to me like an important point isnt it? I mean 1 mm more or less could mean that at the edge of the screen the pixel are seen completely different. So when not taking this into account and directly putting the film with the ink-side to the screen will it work perfectly or does it mean there is enough space between so that at the edge you will see different pixel even though you calculated the rest of the values correctly?

A laser printer at 1200dpi should work. You would think laser would be better than inkjet (maybe it is) but with my particular Samsung laser printer, the printouts were inconsistent. Meaning I would print the same pattern twice, and it would come out slightly different. It was very difficult to work with (although it was enough to get a proof-of-concept). Printing in color might work, I never tried it. That could be interesting. With a light gray it may make the image appear brighter. The parallax barrier line should be about the same size as 1 pixel (or the dot pitch). In practice, it may have to do slightly smaller due to the perspective caused by the glass on the screen. Turning the sheet to face the monitor can also help (and was what I did). But the pattern is always uniform. Once you get the right number, it will work for the whole screen (or a part of it, if you are printing multiple sheets).

Inconsistent? Maybe it was because the rollers that drive the paper were not working together correctly so the paper was driven more at one side? I hope i wont have such a problem...

I dont know if a light gray would be a good idea... because wouldnt that only mean that some dots arent printed to get some more white into it? If so I think it must be a real color so that blue, red and/or yellow is needed to build the color. And probably it cant be too light because that maybe would result in not printed dots too? But then the maximum that could be done would be to use yellow, red and blue together. Not at one point because that would mean to get black but near together. But I dont know what color that would give. Maybe even black too?

I agree with you SebastianJu, it was a nice tutorial. I do print my stuff with a LaserJet though. I think that it prints great quality images. Just make sure that you have it set to 1200dpi. I'm pretty sure that this is what magazine printing companies use when printing too.

white won't work, since you can't actually print white. any color other than black will give a poor result.

The barrier width is crucial. get it wrong and it simply won't work except for a narrow column somewhere on the screen. The air gap between the screen and the barrier is equally important, but that's not a factor when printing the image, so if you have the right barrier you can just trial and error the correct distance.

Hi all.. it's very nice this work and i tried but i have a problem to get the correct pixel pitch of zalman zm-m240w.... the 22'' is 0.282 but this is the 24'' version and in many site the value start from 0.270 to 0.285... i tried 272, 276, 282 without fortune... anyone have tryed? It's possible to calcolate the pixel pitch? (this also in case of make a test for my notebook asus where the pixel pitch of the monitor isn't simple to find)... thanks thousand

Yes you can calculate the pixel pitch by simply measuring the width of your display. The formula is then :
dot pitch in mm = width in mm / horizontal resolution.

For the 22" (16:10) the width in mm is 22 * 2.54 * 10 * 16 / sqrt(356) = 473.86 mm, this gives a pixel pitch of 473.86 / 1680 = 0.2820 mm.

For the 24" (16:9) the width is 24 * 2.54 * 10 * 16 / sqrt(337) = 531.31 mm, which gives a pixel pitch of 531.31 / 1920 = 0.2767 mm. If they didn't lie about the real diagonal size (which happens sometimes with some manufacturers), then you could probably test 0.277 which is closer to the real value. If this doesn't work, then the problem with your barrier should probably lie elsewhere.

If you do measure the actual width you will find out if 531.31 mm is the correct value, an error of 1 mm in the measure won't have much impact on the final result (0.005 mm in this case).

EDIT : corrected, calculations went badly the first time :/.

in this case, 1mm is NOT an acceptable error. 1mm is the width of almost four pixels. There is literally no margin for error with this

The 1 mm error is divided by 1920 in the end, so as I said it gives an error of max 0.005 mm for the dot pitch calculation.

The dot pitch is only needed to get in the ballpark. You still end up needing to do trial and error at some point, because there are a lot of variables at play. So even without the dot pitch, you should be able to make a decent estimate just by measuring the screen and using some simple math.

I hope someone can help me to make a barrier film for my 17inch monitor (sync master 732) to use as autostereoscopic display.I wish to get how can i make the transperent film for this and how can I prepare image for the same.

Did you see my tutorial:
viewtopic.php?p=55961#p55961

I include a test image you could use, but it also works with the iz3D driver.

Tnx for the answer ... 276 ... i tryed but probably i have to set 0.2767 then.. ok...
I'm waiting the new trasparent film for try... (When i have time ........... uff)

no really, if your measurements are 1mm off, you won't get a usable barrier. that one millimeter is almost four pixels, so if you position the barrier correctly on one edge of the screen, the other side WILL be off by four pixels.

sure, the 1 millimeter error is divided by 1920(so it's actually 0,0005mm), but since you're printing at least 1921 lines, that half micrometer is still a millimeter in the end.

so, if you want to calculate your dot pitch for any reason other than this, half a micrometer is probably considered acceptable but for this, you want it as accurate as possible.

Thanks for the correction, as you said it's actually a 0.0005 mm error margin for the dot pitch (1 / 1920 = 0.00052) and not 0.005 mm as I said. Stupid me...

It's in fact even better than what I tought because a 2400 dpi printer has a dot pitch of 25.4 mm / 2400 = 0.01058 mm, which is a lot less precise than this error margin. And the given dot pitch of monitors is generally rounded to max 3 decimals (which is the case for the Zalman ones), which gives a 0.001 mm error margin. Still a lot worse than what you would obtain by measuring the width of the display yourself with a 1 mm error margin.

So in only two tries - by selecting your lower and higher bound for the measure of the width of the display - you should theoretically be able to print the most perfect possible parallax barrier printable with any printer.

But as cybereality said the dot pitch will only get you started with a first approximation, because in the end the precision of your printer won't be good enough whatever its dpi is. So you'll probably have to use uneven values for the tickness of both transparent and black bars, it's probably the reason why using 600 dpi printers can give acceptable results when printing at a 2400 dpi resolution.

And you should also account for the fact that the thickness of your bars shouldn't be exactly equal to the dot pitch. For the effect to work the parallax barrier is not placed exactly on the surface of the pixels, but some millimeters away from them. You don't have the choice anyway because of the thickness of the different strates between the pixels and the surface of the display.

As illustrated in this schema, you can see that a parallax barrier with bars of the same thickness than the pixel pitch won't work, even if this illustration is not at the correct scale :



Unfortunately I don't think there is any mean to know or measure the thickness of the surface of a display. And even when knowing this thickness, the fact that it's made of glass and other materials has an incidence in the way the light travels it. So you'd also need to know it's refractive index, and then use the Snell law to make the calculations for your parallax barrier.

In the end it will be much more simple to do some trial and error, starting with an acceptable approximation and going down till it's correct. Be prepared to consume some transparent paper...