The DSLR camera <b><a href="//commons.wikimedia.org/wiki/Category:Pentax_K-7" title="Category:Pentax K-7">Pentax K-7</a></b> with macro lens Tamron SP AF 90 mm F/2.8 Di MACRO 1:1 and wide-angle lens smc Pentax-M 28 mm F/2.8 installed in "reverse position", using a coupling ring between both filter threads. This combination allows a three times higher magnification (3.2:1) compared to the macro lens alone (1:1). The focal length of the camera-mounted lens – 90 mm, in this case – is crucial to the magnification ratio (calculation is 90:28 = 3.2). It doesn't need to be a real macro lens, any other telephoto lens with that focal length has the same effect. The usage of a tele lens of 300 mm instead would even lead to a magnification of 10.7:1 (theoretically). In order to achieve a larger depth of field, the aperture ring on the reversed lens should to be closed as far as possible (so, it's very useful to have one there!).
<a href="//commons.wikimedia.org/wiki/User:Fice" title="User:Fice">Christian Fischer</a>
CC BY-SA 3.0
<p><span class="int-own-work" lang="en">Own work</span>.<br></p>
<i>Picture taken with:</i> <a href="//commons.wikimedia.org/wiki/File:PentaxK100D_3.jpg" class="image"><img alt="PentaxK100D 3.jpg" src="https://upload.wikimedia.org/wikipedia/commons/thumb/f/fc/PentaxK100D_3.jpg/50px-PentaxK100D_3.jpg" decoding="async" width="50" height="33" srcset="https://upload.wikimedia.org/wikipedia/commons/thumb/f/fc/PentaxK100D_3.jpg/75px-PentaxK100D_3.jpg 1.5x, https://upload.wikimedia.org/wikipedia/commons/thumb/f/fc/PentaxK100D_3.jpg/100px-PentaxK100D_3.jpg 2x" data-file-width="4672" data-file-height="3104"></a> + <a href="//commons.wikimedia.org/wiki/File:PentaxZoomLens18-55WR.jpg" class="image"><img alt="PentaxZoomLens18-55WR.jpg" src="https://upload.wikimedia.org/wikipedia/commons/thumb/5/56/PentaxZoomLens18-55WR.jpg/50px-PentaxZoomLens18-55WR.jpg" decoding="async" width="50" height="35" srcset="https://upload.wikimedia.org/wikipedia/commons/thumb/5/56/PentaxZoomLens18-55WR.jpg/75px-PentaxZoomLens18-55WR.jpg 1.5x, https://upload.wikimedia.org/wikipedia/commons/thumb/5/56/PentaxZoomLens18-55WR.jpg/100px-PentaxZoomLens18-55WR.jpg 2x" data-file-width="2000" data-file-height="1405"></a> (at 38 mm) + tripod.