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Building a Very Cheap DIY Beam Splitter 3D Camera Rig

November 26th, 2010 · 4 Comments · Shooting in 3D


When talking about making a cheap 3D camera rig using two cameras or camcorders for shooting in stereo 3D we are usually referring to Side by Side setups as this is is easier and much cheaper to make for an amateur. Of course mounting two cameras Side by Side has its own disadvantages as compared to a more professional approach in the form of a beam splitter 3D camera rig, but as I said it is easier and much more affordable, you can get the basic stuff you need, besides the two cameras, for pretty much a couple of bucks. When going to beam splitter 3D camera rigs, then amateur 3D photo or videographers should be ready to go for a cheaper and more basic 3D rig, again without the cameras included, that starts at around $3000 USD and goes way up to hundreds of thousands. So if you are a normal user that just wants to shoot in stereo 3D, then you either have to go with the quite affordable all-in-one solutions like the Fujifilm Real 3D digital camera for example, or build a simple Side by Side 3D camera rig yourself, but making a beam splitter 3D camera rig is usually out of the question and you probably won’t go for an expensive already built solution.

I already have built a simple Side by Side 3D camera rig myself and am quite satisfied with the results I got, I even figured out a cheap and simple way to properly align the two cameras for best results. However the drawback with the Side by Side 3D camera rig i have is that I pretty much can’t get the two camcorders I’m using close than 8 centimeters or around 3.15″ which is not that convenient and less than 11 centimeters or about 4.33″. This is due to the physical size of the cameras and camcorders and the only way to get around this inconvenient limitation is to go for beam splitter solution where you may be even able to align the two cameras to match completely or with other words to have zero interaxial distance. Of course as an amateur into that doing 3D just for fun it is way out of my budget to go and purchase an expensive beam splitter 3D camera rig, so I had to figure an alternative. But I was not yet aware that this will not be an easy thing to do, especially when I’ve considered to try and build the 3D rig myself with the major problem being the acquisition of a high quality and affordable 50/50 beam splitter mirror which is one of the most essential things…



I was finally able to find what seems to be a good quality 50/50 beam splitter mirror for my project, however it will take a while for the mirror to arrive and meanwhile I decided to do a quick test with a few cheap alternatives. I’m talking about making a dirt cheap alternative of a beam splitter mirror by using some handy materials like a piece of one way mirror film that is applied to windows and a mirror screen protector for an iPhone from Switcheasy. These two things can act pretty much like beam splitters that just need to be applied to a piece of glass and I’ve used the front glass from iPhone as I’ve had a few of these handy, you can see how the foil and protector look like after applied on the photo above. Then what I also needed was a small box from cardboard to put the DIY beam splitter mirror in, two cameras and a remote to trigger both cameras at the same time and my two faithful old Sony V1s were great for the task.



After a few minutes of work the quick and simple stereo 3D camera rig was assembled and I did take a few photos with it using the two different DIY beam splitter mirrors I’ve prepared. Of course the whole thing was not very mobile, although the whole thing was quite portable in size, so I just moved it to a windows and took some photos over the window. Both cameras were set with an interaxial distance of just about 1 centimeter apart or around 0.4-inches, so the depth in the following few photos I’m posting here may not be that impressive. However the whole ideas was to see how well will the two cameras work with the DIY mirrors and frankly said the results were not that bad as one might expect, although for a top notch quality you should go for a professional solution of course.



The first photo is taken with the help of the Switcheasy iPhone mirror screen protector and as you can see the result is quite good, here both the left and right frames were equalized to have more matching colors. You can however notice some color deviations that were probably caused by different polarity of the light, but still the end result was quite good.



The second photo here is again taken with the Switcheasy iPhone mirror screen protector, but there is no color equalization done to any of the two frames, so that you can see the slight variation between the two. Again very good result in terms of quality, meaning that the optical qualities of the product are quite good and close to 50/50 transmittance-reflectance. However with different such mirror screen protectors the results may greatly vary, so do not expect to achieve the same result with quite any of them, although you may even get lucky and find even better one. The only thing you should be careful here is not to get dust and dirt between the protector and the glass on which you are applying it on, otherwise the visual quality may degrade further.



Next comes the other half mirror that uses the one way window foil. I had high expectations from this one too,e specially after getting so good results with the iPhone mirror screen protector, however I was quickly disappointed. It seems that the optical qualities of the two sides of the one way window foil are quite different with the one much better than the other as you can see in the more blurrier right frame. On this photo I did some color equalizing for both views to be easier on the eyes.



The second photo with the DIY mirror using one way window foil shows pretty much the same not so good results, but the difference here is that I did not try to match the colors on both pictures after taking them with the help of an image editing software. It turns out that the optical properties of this foil can also vary a lot between different brands and products, so you can get different results by trying different ones.

The important conclusion here is that the optical quality of a beam splitter mirror are very important for achieving great quality photos and videos in stereo 3D format when using a beam splitter 3D camera rig. You can try to make yourself a kind of a half mirror with handy and cheap materials, but the level of quality you get may greatly vary, so it can take a lot of experimenting and time. Still you can get very decent results with a dirt cheap solution, so it is worth trying if you are interested…it is also a good learning experience that can further help in developing a more advanced 3D camera rig.

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