Opera Glasses
- September 26, 2013
- 274 Downloads
- 3 Likes
- Blender 2.6x
- Render: Cycles
- Creator: ampace
- License: CC-BY
Description:
These glasses are based on the Zhumell Mezzo Opera Glasses. They are set up to be rendered in Cycles, currently, and there are 4 separate Cycles materials - black enamel, black plastic, glass, and polished brass. Interestingly enough, due to the shape of the lenses, these opera glasses actually magnify if you look through them!
This is a high poly model, running 9641 total verts. The glasses aren't rigged, but the handle is a separate object from the glasses, is parented to the glasses, and has the transformations locked so that it only rotates along the hinge axis.
Comments:
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ampace
Edited September 27, 2013Hi FayZee, I'm glad to hear you like them, but sorry to hear that you're having difficulty with the orientation of the magnified image.
I suspect the reason you're seeing an upside down image through the glasses is due to the inaccuracies of the lens. Unfortunately, I never designed the lenses to be looked through - I simply wanted to have something convincing when the glasses were seen. I will try a couple of things to see what happens when I create authentic lenses for the glasses, and if I have luck, I will update this model with my results.
In case you're interested, here's some more info on optics: http://en.wikipedia.org/wiki/Lens_(optics)
EDIT: After taking a look for myself, I am convinced that the reason the image is flipped is because the lenses are shaped incorrectly. Additionally, I think I can get more magnification out of them.
EDIT 2: Actually, I discovered the real issue after some research - I need 2 biconvex lenses, rather than 2 convex lenses. facepalm
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FayZee
Written September 27, 2013Thanks for the link and the extra information. I looked up "biconvex" and found some data relating focal length to image inversion here:
http://www.eschenbach.com/products-hand-held-magnifiers-biconvex.htm
which has helped me to understand a bit more.
I would be very interested to see how this can be solved and if there is more than one solution.
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ampace
Edited September 27, 2013After some experimenting, I've discovered that the proper way to get the magnification and the non-reversed image is to use one biconvex lens on the large side, and one convex lens on the small size. It also helps to have a proper lens shape.
For the initial version of the lens shape, I simply scaled down a sphere until it was close to the right depth. This caused the edges of the lens to be steeper than they should have been, which caused a ripple effect in the image. For the 2nd attempt, I created a large, high poly sphere (64x64, if i remember correctly), then deleted all but the first several rings. I duplicated the result and flipped it, joined the verts and recalculated normals. This seemed to work, but I still had to play with the depth of the lens to get it right. I also discovered that all of the lens radii need to match up in the in so that the image isn't warped. You will see in the new version that my lenses still aren't perfect - I didn't have time today to learn the ins and outs of optics! :)
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ampace
Written September 27, 2013New version uploaded. Test it out and please let me know what you think!
Thanks.
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FayZee
Written September 29, 2013I've tested it with my multi-line text object, using your original camera set up, at a focal length of 42 and again at 155 for a close-up.
The text is perfectly clear now and right-side-up.
It's still not magnified, but that's okay, you've explained the type of lenses that should be used, and for that I'm grateful. I realise that one shouldn't expect a render of a model of binoculars to actually show magnification; that's something I would expect of a model of a magnifying glass.
Maybe a render of a single pair of lenses could show the magnification, as in an illustration for a physics tutorial. But in your model the lenses are not separate objects, so I couldn't test this.
I just have to say again that the model renders beautifully and this has been an intriguing discussion. Thank you.
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Lomar
Written September 27, 2013A lovely model, thank you!
And a most interesting discussion about optics. Makes sense that since Blender is mimicking how light travels in real life, a lens-shaped object would act as a lens. Yet it is something I never ever would have thought of!
A most interesting thought indeed! There are some real possibilities here....
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These opera glasses are beautiful looking. Thank you so much for sharing.
I bet they were heavy to use. I say this because we had a small pair of binoculars with glass lenses, which had a metal body covered in leather. They felt very nice to handle but were heavy in use. They must have been quite old, but I was fond of looking at them, if not actually through them :-)
Well, I added text to this scene. The phrase "Small text made larger by magnification" with an array modifier to produce ten lines. I rotated the glasses so that the right lens was perpendicularly aligned between the camera lens and the text. When rendered, the text seen through the right lens was definitely transformed, but appeared upside down.
I'm not sure about optics and I realise that opera glasses are designed to be used by two eyes. But is there some little adjustment I could make so that the text appears the right way up?
I made one render with the camera position and configuration the same, and another by shortening the focal length for a close-up. In neither was the text actually larger. So under what circumstances can I produce a render to show magnified text?