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Comment by namibj | Hacker News Reader

I assume it's just very narrow FOV and not achromatic.

From the fine article:

  > The only parts of the lens that can’t be 3D printed are the
  > glass optics, and for this Steele used Surplus Shed to
  > acquire achromatic (two-part) lenses.

I can’t help but feel that’s no longer "3D print… a… lens".

Everything else? Sure, nice job, but not exactly surprising.

In photography, a "lens" generally refers to the mechanical component that houses the optical lens.

In 3D printing, "print" generally refers to "most of the device, except those components that one versed in the field would recognized as being composed of materials not suitable for printing".

Though I do agree with you, many people who do 3D printing would not find the title misleading.

Nope, a lens holder is the mechanical component. Most people and people in industry would refer to either the optical element(s) or the complete assembled optic as the lens.

I am referring to the complete assembled optic.

>> "In photography, a "lens" generally refers to the mechanical component that houses the optical lens."

Where did you hear this? I probably see people use "glass" to refer to lenses as often as I see "lens."

Try Google Images:

https://www.google.com/search?q=photography+lens

You'll see not a single glass lens by itself, but rather every image will be of an assembly containing optical lens intended for mounting to a camera.

Also, enter any photography store and ask to see the lenses. You'll not be presented with discrete glass, but rather with assemblies containing glass intended for mounting to a camera.

Perhaps in the eyeglass industry the term "lens" refers to the glass itself as a discrete component, but not in photography.

In the imaging industry the lens assembly is normally called an objective. In every field I've worked in, the lens is the glass and nothing more. If photography uses this term, it's wrong, but if it's established... who cares, just know that fact and move on.

It makes sense in photography where we don't really deal with or think about individual lens elements aside from people who repair their own, or when some new kind of element appears. We also call the whole assembly glass sometimes, though some people think it's pretentious. It's more common in blogs/YouTube/etc than in actual practice where focal lengths and f-stops are usually the main language of lenses.

The issue is that while you can print 3d lenses (fun read: https://formlabs.com/blog/creating-camera-lenses-with-stereo...), it's just not practical unless you're super into the project (similar for telescope makers who grind their own lenses). The long and short of it is that high quality glass is an industrial process that has hundreds of years of refinement to give you excellent image quality at very low prices.

That said, I have cnc'd a piece of acrylic, polished it, then used it to make a silicone mold and used that to make an epoxy lens.

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