Slashdot Mirror
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."
He built an extension tube from a Pringles can and stuck a Canon lens on the front. This is not "building a lens".
"I'd rather be a lightning rod than a seismometer." -Ken Kesey
What he really built was an extension tube to allow an ordinary
lens to focus closer.
http://mirrordot.org/stories/a6cd3d2482ab26fa99636 acc4d255044/index.html
/. tech monkeys include a Mirrodot/Coral Cache link as part of the story template? It would help defray the /. effect (smoldering servers and whatnot).
Why don't the
http://www.networkmirror.com/AodpyYLsgUIgSIiH/www. photocritic.org/2005/macro-photography-on-a-budget /index.html
"I'd rather be a lightning rod than a seismometer." -Ken Kesey
http://www.photocritic.org.nyud.net:8090/2005/macr o-photography-on-a-budget/
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.
Robert Cringely did just that; see the following link:
. html
http://www.pbs.org/cringely/pulpit/pulpit20020207
A macro lens is capable of taking pictures of things in much more detail than a normal lens. Think of a steel countertop at a moderate distance it would look much like an ordinary camera picture of it would, but if you look a littlem ore carefully even from a few feet away you can usually see scratches in the surface. A macro lens allows you to focus closer than the usual minimum focal distance so you can capture that detail. Normally you'd only be able to get so close and then it'd just get blurry instead of clearer macro lenses are designed to overcome that limitation.
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."
These kinds of extension tubes are quite common things, and cheap. I have a number of them for my M42 mount cheap-ass Praktika camera. I think they cost about 2 pounds overall. :)
The guy has a D20, if he is rich enough to pay for that camera, he should ne able to afford a proper and good macro lens. Extension tubes are a pain when you are holding the camera and trying to focus but they are cheap alternatives for the real thing. I think the correct terminology is bellows or something like that. I have the stuff lying around but never bothered the learn the correct terminology.
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.
A very nice way to do macro photography is to place that 50 mm (or similar) lens reversed in front of your lens. You can buy a reversing ring for the purpose. It is easy to do if you only have threads for the reversing ring on your camera (many point and shoot digital don't). Just zoom in (to minimize vignetting) and stop down the lens you are mounting the (wide open) normal lens on.
If you are serious about doing macro photography but don't have to budget to buy a macro lens for your SLR, best would be to use a lesn reversing ring to put the lens backwards on the camera. That way you can use your regular lens as a very good macro lens. Focusable, zoomable, what ever... won't even cost you much more then a box of pringles and no risk of geasing up your SLR.
Adding an extension tube changes the minimum focus distance but doesn't change the focal length. Adding a teleconverter, on the other hand, changes the focal length but doesn't change the minimum focus distance. (Unfortunately, Canon and perhaps others call their teleconverters "extenders", which some people confuse with "extension tubes", although that's as wrong as confusing KDE with X.) Either way can increase the effective magnification factor of the stack, but the mechanisms are completely different (orthogonal, even).
Since the f-stop is related to the focal length and aperture, using an extension tube on a 50mm lens at f/16 will give you a stack that is still f/16. Using a 2x teleconverter, on the other hand, will double the focal length, giving you a stack that is two stops slower, i.e. f/32.
And for those of you who don't know what a "stop" is, stopping down (darker) one stop halves the amount of light that makes it through the lens per unit time. This is related to the aperture (opening) of the lens and to the square of the focal length, so multiplying the focal length by the square root of two (approximated as "1.4") will reduce exposure by one full stop. (Teleconverters commonly come in 1.4x and 2x, which reduce your f-stop by 1 and 2 stops, respectively.)
A foot away is just tremendous distance for a modern mid-priced digital camera. I have a Minolta-Konica Dimage Z5 whose "super macro" mode, while somewhat depth-of-field challenged, can take pictures within a centimeter of the lens. That's on a camera with an image-stabilized 12x optical zoom, too, so it's not like it's the intended strong point of the model. IIRC there's a slightly more recent Canon, also with a longer-than-normal optical zoom, that can take snaps of stuff that's essentially touching the face of the lens.
That's on your $500-USD tier of cameras. Granted, the DOF is not perfect, and I'm sure it's less than a flat field, but the newest midlevel consumer digicams are lots better than a reflective Pringles can...
"Fundamentalism" isn't about divine morality. It's about human authority.
Yeah, I almost pointed that out as well, but I figured that some people would say that even $20 or whatever a legitimate bellows or extension tube costs is big bucks to them, and how dare I suggest that it was cheap. :)
But you're right, the part he's replacing isn't a terribly expensive one. And frankly I don't have a bunch of extra body caps sitting around either. (For some reason I'm always short them, probably because you only get one with each camera body, and they like to grow legs and wander off.)
Some of the macro bellows can get quite pricey -- I just did a quick google and some of them are $500+ (for Leicas I think), however there are also ones on ebay for less than $60, so I don't doubt that a person could find one cheap if they looked for more than five minutes. The actual Canon extension tube that this pringles can is simulating retails for about $170, and I'm sure there are generic parts for a lot less.
In short I think this review might be interesting for someone who wants to try macro photography, but unless you're dirt poor and inherited the camera or received it as a gift or something, it's not terribly expensive to get a real extension tube, and I think anyone would be a lot happier.
Plus with a real tube, there's not the same risk of having the lens fall off the front of it and go crashing to the ground. And no pringles grease on your lens, either -- frankly this is what would keep me from ever putting my lens inside a Pringles tin. Can you say oily?
"Ladies and gentlemen, my killbot features Lotus Notes and a machine gun. It is the finest available."
False. When they say "build a Pringles can network antenna", they are literally building an antenna. This guy isn't building a macro lens, he's building an extension ring to adapt a regular existing lens for macro focusing.
If a job's not worth doing, it's not worth doing right.
I saw this and went down to the camera store to get a lens and body cap to mount it, and the owner, showed me something else that works better. I use a pentax k mount so there are a lot of old teleconverters and only for about 20 bucks. All you have to do is tap the lens elements on the edge to unscrew them. Then you have a very sturdy mount and about 25mm of extension.