<p>Not a great photo, and only one eye is in focus, but taking <i>anything</i> at 10:1 magnification and f/5.6 with a bellows is a small feat in itself (especially difficult if it is a jumping spider, but this guy spent some time cleaning his fangs with his palps, giving me a chance to try a high magnification shot). I used the 28mm reversed on extension tubes mounted to the bellows at full extension. The field of view as shown above is likely ~1.5mm give or take a bit, I'm guessing pretty roughly. 
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I photographed a ruler using the above setup, and I could just barely fit 2mm in the field of view.
<a rel="nofollow" class="external text" href="https://www.flickr.com/people/7539598@N04">Thomas Shahan</a>
CC BY 2.0
<a rel="nofollow" class="external text" href="https://www.flickr.com/photos/7539598@N04/2955962619/">Adult Male Hentzia palmarum Jumping Spider</a>