{"id":609,"date":"2007-10-16T23:47:50","date_gmt":"2007-10-16T14:47:50","guid":{"rendered":"https:\/\/regex.info\/blog\/2007-10-16\/609"},"modified":"2007-12-11T16:50:02","modified_gmt":"2007-12-11T07:50:02","slug":"macro-photograhpy-and-reverse-lens-basics","status":"publish","type":"post","link":"https:\/\/regex.info\/blog\/2007-10-16\/609","title":{"rendered":"Macro Photograhpy and Reverse-Lens Basics"},"content":{"rendered":"\n\n
<\/a>\nNikon D200 + reversed Sigma 30mm f\/1.4 — 1<\/sup>\/<\/big>250 sec, f\/16, ISO 160 —\nfull exif<\/a><\/span>\nPart of a Japanese 2,<\/span>000-yen Banknoteat 650× Magnification<\/span>\n<\/div>\n\n

Well, I'm not sure<\/span> “650× magnification” is exactly the right way\nto say it because there are so many ways to lie with numbers. The area of<\/span>\nthe bill shown is about 8mm by 5.3mm, or about 0.066 square inches. With an\naverage LCD<\/span> display at 86 DPI<\/span>, the image above appears at about 8 × 5.4\ninches, or about 43 square inches (although how big it appears for\nyou<\/i> depends on the physical size of your monitor, your monitor's dot\npitch, your desktop size, and perhaps some browser settings).<\/p>\n\n

So, from the actual area of 0.066 square inches to a display<\/span> area of 43\nsquare inches, that's a jump<\/span> of about 652 times.<\/p>\n\n\n

Of course, the small image above is greatly reduced from the\nout-of-camera original. Clicking through to a somewhat<\/span> larger version<\/a> yields\n4,435 times<\/b> magnification, while the un-resized original yields over\n20,500 times<\/b> magnification....<\/p>\n\n

<\/a>\n20,520× Magnification<\/span>\n<\/div>\n\n

Wow.<\/p>\n\n

I'm impressed by these numbers perhaps only because I'm new at this, or\nperhaps I've made some basic error in math, but it seems pretty darn cool\nto me.<\/p>\n\n\n

I'll talk a little<\/span> in this post about this kind\nof macro photography, but first, to give a sense<\/span> of the sizes, here's a\npicture<\/span> I snapped<\/span> showing the Japanese 2,<\/span>000-yen bill, the seed pod from yesterday<\/a>,\nand some other things I photographed<\/span> and will talk about.<\/p>\n\n

<\/a>\nNikon D200 + Nikkor 17-55 f\/2.8 @ 55mm — 1<\/sup>\/<\/big>60 sec, f\/8, ISO 160 —\nfull exif<\/a><\/span>\n\n\n\n\n\n
\n 2,000-yen Bill (view 1)<\/span>\n Seed Pod<\/span>\n Leaf<\/span>\n 2,000-yen Bill (view 2)<\/span>\n\nMouseover the box to highlight the area photographed\n<\/div>\n<\/div>\n\n\n

Mouseover the boxes to highlight the approximate area of each item\nphotographed (the seed pod, however, was at somewhat of an angle, so more\nof it showed up in the frame than is indicated here). The leaf and<\/span> the\nother view of the bill are shown later in this post.<\/p>\n\n

In the upper right is the Sigma 30mm f\/1.4<\/a> that I\nused<\/span> to take the macro shots. Between it and my point-n-shoot camera is the\nNikon\nBR-2A<\/a> lens reversing ring, attached to a Nikon\nBR-5<\/a> 62mm adapter ring. Using this combination, I can mount<\/span> the Sigma\nonto my D200 backwards<\/i>, so that the part normally stuck to the\ncamera body is sticking out, facing the subject.<\/p>\n\n

Here's a picture of it that Anthony happened to take while I was<\/span> working\non this yesterday. At four years<\/span> old, he has no understanding of “minimum\nfocus distance” and only a little<\/span> understanding of “being still,” so the\nresult is blurry, but you can see the lens\/body contact pins at the very\nbottom center. Normally, they're inside the camera body, but when the lens\nis reversed, they're on the far outside.<\/p>\n\n

<\/a>\nWorking The Aperture on a Reversed<\/span> Lens<\/span>photo by Anthony M. Friedl, age 4\n<\/div>\n\n

It feels decidedly wrong<\/i> to mount a lens<\/span> on backward, but for\nwhatever reason, it can create some great magnification. Generally, the\nwider the lens, the more magnification. (That is, a 30mm<\/span> lens used this way\ncreates more magnification than a 50mm<\/span> lens used this way.)<\/p>\n\n

Before going into details on this ungainly setup, I'll offer a few<\/span>\ngeneral comments about macro photography...<\/p>\n\n

Macro Basics<\/p>\n\n

Macro lens magnification is measured by how large an image it projects\nof something onto the film\/sensor, relative to the thing's size in real\nlife. “1:1<\/b>” or “1×<\/b>” means that an object appears on the\nsensor at its actual size. “2:1<\/b>” or “2×<\/b>” means that it\nappears at double actual size. The opposite, “1:2<\/b>” or\n“0.5×<\/b>,” means that it appears at half its actual size.<\/p>\n\n

None of this, by the way, says anything about how large a print<\/span> you can\nmake from the result, which depends on a lot<\/span> of other, unrelated\nthings.<\/p>\n\n

The generally-accepted definition of a “macro lens” is one that can\nproject at least as large as 1:1<\/b>. Most lenses don't even come close\nto this: the best my pro-level 70-200\/2.8<\/a> can do is 0.16×<\/b>, with my 17-55\/2.8<\/a> doing only\nslightly better at 0.2×<\/b>. For “normal” photography, one generally\ndoesn't really care about any of this, so this lack of magnification is not\na problem.<\/span><\/p>\n\n

For those wishing to get very close up, most lens manufactures generally\noffer a few<\/span> lenses with a macro<\/span> mode that allows 1×<\/b>\nmagnification, but some manufactures get a bit<\/span> generous with the “macro”\nlabel, so be careful when shopping. It's not uncommon<\/span> to see 0.5×\nlenses marketed as macros, and I've even seen a 0.13×<\/b> lens\nlabeled “macro.”<\/p>\n\n

Other Macro Solutions<\/p>\n\n

A dedicated macro lens is by far the easiest to work with, but if you\nwant more magnification and\/or less cost, a number<\/span> of other ways are\navailable...<\/p>\n\n