Nagahara's 180 deg catadioptrical hmd replication

[3dpmaster]

Nagahara's 180 deg hmd replication.

Finally, I had the possibility to get custom mirrors in a university. There are two mirrors alined to eachother.
I saw the image is distorted like a curved valley. If I can take a picture with the same distortion, the viewed image will be corrected.
The setup is a big issue because the aligment tolerance between focal points is very small.
The fov is less than 180 deg ---> 160 deg because of the enclined mirror (patent description).

to be continued....

[cybereality]

Awesome work bro! What are your plans for this (ie will you be selling kits or is this personal use only)?

[Okta]

You certainly have chosen a complex project and if you can get is workable will be a huge achievement. Wishing you great success.

[FingerFlinger]

Really excited to see your progress. Very impressed!

[PalmerTech]

Sitting on the edge of my seat with this, being able to ditch traditional refractive optics would be great!

[3dpmaster]

thanks

It is extremely difficult to get a smoother mirror surface without cnc and whithout lathe. The image is not that perfect. There are some curvature errors, the mandrel was made from wood. The sharpness of the image is ok, but the aperture is not so great. The image is not bright enough because of the small beam exit from the cone mirror. The big advantage of this mirror device is the use of any magnifier, even a standard 50mm photo lens can be used for a sharper image.
The main image format is as big as a 35mm diapositif (very small for a 160deg fov hmd).

I have plans to make a new mirror with a mandrel from metal (cnc). The following test is the ultimate 3D test (also done with 35mm dia's). The final assembly would be set on a moped helmet.

Unfortunately, I cannot sell kits of this devise because it is from a patent.

[DixieFlatline]

Can we get more pictures of the device and it's function?
Perhaps a demo using dual camera rig?

[3dpmaster]

Sorry for this late reply.

The conic mirror is not so good because the focal legnth is too short, it cannot reach the ellips. I have to make a new one with a longer focal length. This will reduce the field of view of the incoming rays through the lens group. The FOV of the primar mirror will stay the same (180 degrees).
If I have better results, pics will follow.

[3dpmaster]

Big surprise on my last optical tests, the mirrors can go over the 180 deg!!!!
Mr Nagahara could rotate the mirrors a bit more. Now I have 200 degrees somewhere, I can't believe my eyes
I still have to get rid of these vignette errors.

[brantlew]

Cool. Are the mirrors polished? How clear is the image they produce?

[cybereality]

Sounds amazing. Please try to take a photo if possible.

[3dpmaster]

Sorry about this long waiting time. I'm trying out different mirroring techniques that I can do by myself. Half silvered mirrors like the aircraft helmet mounted displays is a big possibility.
The curved mirror devise can be used in augmented reality If I use these curved half silvered mirrors.
More will come as soon as possible

[3dpmaster]

other pics of the 'stitched" concave mirror.
One mirror weights around 10 grams.
The construction is more complex than I expected, but I can make it.
It is just a manner of a correct focus alignment.
If the correct cone mirrors are finished, I can start the assembly.

[FingerFlinger]

Very cool. It looks like they are maybe scotch-taped together right now? Are you going to mount them and do a final polishing once they are in place? Just curious how you will manage the seams, or perhaps they are not a problem because the eye can't resolve them at that distance?

[cybereality]

Looking good.