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<p>[QUOTE=&quot;SuperDave, post: 2416985, member: 1892&quot;]The bellows does not impede the light, because it&#039;s not in the way of the light. The only relevant light is that proceeding directly from lens to sensor. The bellows is <b>significantly</b> larger than the lens glass in our application, in the case of my Componon-S (and most duplicating lenses), <b>double</b> the size.</p><p><br /></p><p>What <b>does</b> impede the light is the fact that magnification affects aperture in a mathematical relationship, the greater the magnification the tighter (higher numerically) the &quot;effective&quot; aperture. You didn&#039;t run into that in sports photography. Further, 1:2 magnification gets you a Morgan filling the sensor, but nothing smaller, and the goal is to fill the sensor with the coin. So you need yet more magnification, meaning yet tighter apertures and quicker onset of diffraction.</p><p><br /></p><p><b>Diffraction is the enemy</b>, and magnification hastens the onset of diffraction. We&#039;re working at a resolution scale where <b>any</b> diffraction creates a noticeable degradation in quality. That&#039;s the specific reason I&#039;m working with a 10MP sensor rather than higher - diffraction is also a function of pixel pitch and the larger pixels of a 10MP sensor allow me an extra stop or so that I can then burn in increased magnification before the onset of diffraction.</p><p><br /></p><p>Digital zoom is not relevant to macro photography. If you want to zoom your image digitally, do it with far more sophisticated software and far more powerful hardware on your PC, not in the camera. By this method, you&#039;re manually focusing on your monitor anyway, and ought to be able to see if it&#039;s in focus or not. <img src="styles/default/xenforo/clear.png" class="mceSmilieSprite mceSmilie1" alt=":)" unselectable="on" unselectable="on" /> Digital zoom in-camera pretty much abandons any pretense of sharpness as it forces the camera to add pixels to fill the same space as the sensor does natively.</p><p><br /></p><p>So your 105 will require a bellows or spacers to increase the magnification to something acceptable, plus the <i>assumption that the lens will remain sharp at a magnification it wasn&#039;t designed for </i>since, out of the box, it&#039;s unsuitable for anything smaller than a Dollar and - it should be mentioned - requires a working distance beyond the capability of many stands. Assuming it is OK at higher mags, and you have the ability to place it a sufficient distance from the subject, then the 105 is a possibility as one of the lenses for use with this system.</p><p><br /></p><p>I am going to have to modify my technique rather heavily to evaluate the 150mm&nbsp; El Nikkor I just acquired. My stand - which has enough extension to employ a dSLR with a Canon 100mm Macro, I&#039;ve done it - will not come close to the extension I need for 150mm.[/QUOTE]</p><p><br /></p>

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