4eyes lens testing and face scanning (medical devices)


Hi everyone,

I’ve been talking to Michael Balzer (@mebalzer), creator of the very useful 4eyes lens adapter he’s created; which you can purchase from his store here:

Thought it would best to share the conversation with the forum. The 4eyes is quite an amazing improvement to the structure for high res scanning. Very impressed with the results we’ve been getting:

In these tests I was using the scanner via usb cable, plugged into my laptop- which has a fairly powerful graphics card for a laptop: (NVIDIA GEFORCE GTX 860M - 2GB GDDR5 VRAM). So that may have something to do with the quality I’ve been getting. I find that I’m getting best results setting the bounding box to around .7M without X2. We’re very curious to know what others are getting from different settings- anyone doing 4eyes tests, please reply to the thread with screen shots and settings.

The goal here going for the best high-res (relatively quick) close detail scan we can. We’re using the scans to produce medical devices; specifically, my startup Metamason is using the structure in our process for creating custom fit CPAP masks for sleep apnea patients. We’re interested in the human nose (fitting CPAP masks to it)- anything we can do to improve compliance and coupling to the nostrils (hard to scan) has benefits.



Really interesting stuff, Les. Not least because I’m a CPAP sufferer myself. Oh yeah. And OSA. The 4eyes certainly seems to give a significant improvement over the stock Structure when used for facial scanning.

I notice from the 4eyes website that one needs to fit a separate lens for the iPad’s camera if one wants a fully textured image. I assume you don’t need a texture for your purposes but wondered whether you have one anyway and if so, where you got it.

One other question: Have you tried the Itseez3D app with 4eyes and, if so, did you get a similar improvement in results?

Keep up the great work




My understanding is that 4eyes is not yet compatible with Itseez3D as they haven’t picked up their kit from their California office yet. You will also need the RGB lens to complement the Structure 4eyes lenses in order to bring in textures. I haven’t had the time to test 4eyes thoroughly since I got my unit last Monday.


Hi Missingman,

I work in a hospital system in the Trenton, NJ area. In addition to two hospitals and 12 clinics we have a 12 bed Sleep Center.

I am a Network Engineer and 3D printer Maker-Geek. I have built 2 3D printers and customized a 3rd and I am working on a Delta and I have been doing scan with the Structure.

I am not familiar with the 4eyes lens. I would like to get more information.

What application did you use to connect your Structure to the laptop. I have a Sony vaio with a Core i7 and an Nvidia video card.

I have used the Structure with the Skanect application.


Hi @missingman, have you tried scanning faces using only the iOS device? It would be great to know about the accuracy of the scan with few processing resources.


Answering a few questions:

  • I have tried using the iPad for scanning; the resolution sans 4eyes is no go. But with the 4eyes, ipad facial scans turn out good enough for our purposes. Very much looking forward to tests with the new A8 processor on the iPhone 6/soon to be released refreshed iPad lineup. If anyone does a test with a new iPhone, please let me know.

  • I haven’t used Itseez3D as of yet, looking forward to experimenting with it.

  • The 4eyes people also make an attachment to magnify the lens of the iPad (but the part I received from them to do it doesn’t fit). I’m about to design and print my own, in addition to play with my own variations to their design. I encourage others with a printer to do the same. The key part appears to be a Fugifilm Diopter lens; I just ordered a few with some additional diopter lenses of other magnification levels so we can experiment.

  • I’ve been scanning from Skanect using the hacker cable connected to my laptop (specs in my earlier post)

  • To the guy building the delta 3D printer (good fucking luck); delta’s are such a royal pain in the ass to get working properly… as if its not a big enough pain in the ass to get linear axis printers to behave consistently. I’ve built a rostock max before, after the experience I had, am never messing with delta printers again.


Thanks for the heads up on the diopter lenses! I have been looking for just this, since I do have a 3d printer of my own but have been unable to properly experiment with all the different diopter possibilities to get it working as well as your results have given you.

Any chance that you would make available the stl if you do complete your own design? I seem to always have trouble doing snap fit designs on my own.


As requested:

Here’s Metamason’s design for our own version of the 4eyes lens mount, for the Fugifilm X1 Diopter lenses;

And then here’s Metamason’s design for a front facing mount/stand for the iPad Air, to enable 3D selfies.

Enjoy y’all,


Highly appreciate it! thanks


Nice one, Les! Lenses are in the mail. :smile:


Just a bit confuse here.

So I have structure but the scanned object never be this good.
What is 4eyes? is it different from structure or some kind of custom thing you made from Structure?

Thank you and sorry for the newbie question.


hey @truyen_le , so the 4 eyes is a set of ‘glasses’ for the structure sensor that allows it to focus more on things that are closer, instead of further away, kinda like reading glasses do in real life. It goes on top of the sensor and the projector to zoom in a little, and allows you to gather more details. The downside to this is that it distorts the outer edges a little, as well as makes it longer to take a scan.


Thank @fgvalle. Now I got it.


@fgvalle, you are pretty much correct, but I don’t’ agree that it takes longer, other than you are closer and require more movement to cover the same area. I spent two hours scanning non-stop last night with some of the worst test subjects – kids! and was able to do 180 upper chest and head in 15 seconds. I can shave another few seconds off if we allow the volume rocker to be used with BT shutter switch so you don’t have to use two hands touch the screen.

Also the lenses do not magnify per say, they allow you move closer to the object, I am changing the focal distance.

Optimizing scanning for highest resolution on small objects

To make clear Les is the CEO of Metamason. Also, I sent you RGB lens version that works with the 4eyes quick connect/disconnect bracket. I apologize for sending you the wrong version and will send you the proper updated version this weekend that will work with our iPad Air or iPad mini Retina. Since you already have the lens, I will send you just the bracket.

Thank you

Mike Balzer
slo 3D creators



I have tried to access the 4square page to but your product but I cant access the buy it tab. It is greyed out and indicates
“sold out”. Are you still selling this?




Is possible to get any colors with the 4eyes ?


It is, what color would you like?
There is a little more cost involved, but these brackets are made SLS via Sculptify. I have also made this available for sale through them as well. I have tested the polished white variant and fit is as good or better that the Fortus 250 FDM ABS Plus material. I have sprayed this bracket with red rubberized material on both inside and outside surface. Looks pretty good and fits like a glove.
Let me know, if you want to order directly from Sculptify – which is a good direction to go if you are in Europe, but you will have to buy and insert the lenses yourself. Or you can buy it from me with three lead time.
I hope this helps.
Michael Balzerslo 3D creatorsAll Things 3D805-3D5-8511


After all I thing I be ok with the regular color.

I need to capture high definition details plus RGB color as well, can you please send me a link to choose from. I would like to buy it from you I don’t have the time to do any assembly. Can you Send this in Toronto Canada?


Hi, I’m also interested in ordering one of your 4eyes systems but get the same greyed out button on your 4square page. Let me know when you have another batch of them ready.