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Macro Lens from a Pringles Can
isharq writes "In a cool little feat of extremely low-tech hardware hacking, Photocritic has created a macro lens out of a Pringles can. According to the article: "with less than £1 worth of equipment, a little bit of sweat and tears, you can build yourself a surprisingly good macro lens". The results are astonishing."
Most lenses are designed to focus on things in the FAR range - ~10+ feet. Macro lenses can focus on things very close or very small - in the 1' range.
So if you plan on shooting yet another flower and calling it 'art', you need a macro lens.
Note that many recent digitals offer moderate macro functions and do not require a macro lens.
Actually a true macro lens usually has additional lens elements to correct for various defects resulting from the decreased subject to lens distance. Also they stop down more. While a 'normal' lens can stop down to F16 (sometimes F22), a true macro will go down to F32 or even F45 for greater depth of field.
http://www.photocritic.org.nyud.net:8090/2005/macr o-photography-on-a-budget/
"Programming is like sex: one mistake and you have to support it for the rest of your life."
Focusing distance is not sufficient to qualify a lens as a macro. There are close focusing lenses that are not macro, and there are macro lenses with long focal lengths that don't focus particularly close.
A true "macro" lens is defined as a lens that allows for at least 1:1 reproduction of the subject image on the recording media. For the sake of simplicity, we'll talk film. If you photograph an object that is 1/2" across, and the resulting recorded image on the film is also 1/2" in size, you're shooting macro. A "macro lens" is one that is capable of rendering at least this 1:1 reproduction.
Unfortunately, many camera/lens manufacturer have abused the term to mean "focuses at a (slightly) closer distance than a normal lens at an identical focal length, so that when printed to standard 4x6 the image is life-size." This, of course, is regardless of the reproduction ratio of the lens. A rather silly definition, really, since any reasonable frame at any magnification can be cropped and enlarged to "life size" up to a point before quality degrades enough to become unworkable.
At 3 A.M. you can see people's auras; at five you can see their contrails...
What this guy built is an extension ring, not a macro lens. He used an existing lens, he chose non-macro lens, a macro lens would provide more precise focusing and flat focal plane but otherwise would work the same.
What he built is called extension ring, it fits between the camera and the lens and allows extremely close focusing of any lens. Extension rings go for $20-$40, sometimes you can find them used for less, or you can by a set of 3 for around $100. Factory-made rings usually preserve automatic functions of the lens, at least aperture control, sometimes even autofocus. They are usually much shorter than the pringles can, anywhere from 9mm to 45mm (and you can stack them).
So this little contraption does save you some bucks, just not as much as you might have hoped if you read the title and priced a macro lens.