Macro Lens

[LineMartel]

<p>I bought my first macro lens 2 months ago. I was told on a critique on one of my photos that the sharpest aperture for my lens (Tokina ATX 100 AF PRO D f/2.8) is at f/5.6.<br>

I am confused, as the lens transmit the effective aperture to the camera reading, accounting for the stop down created in macro. Is the sharpest aperture of f/5.6 the setting or the effective aperture?</p>

<h1 id="product-name"><strong><br /></strong></h1>

[craigd]

<p>They probably meant that the lens is sharpest when the camera displays f/5.6. I own the same lens, though, and my tests show excellent sharpness from f/5.6 to f/16. There is probably a peak at around f/8, but the difference is negligible within that range.</p>

<p>More important than sharpness, though, is getting the right amount of depth of field for any particular shot. If you need f/22, use it, knowing that you're trading a bit of sharpness for DOF. You really shouldn't worry about what f-stop is sharpest.</p>

[Wouter Willemse]

<p>The sharpest is 2 or 3 stops down from wide open. Mine used to be perfectly fine sharp wide open on a D50 (6MP), but with the 12MP of my current camera, flaws are more visible. At f/4, focussed to infinity, this lens is perfectly sharp in my eyes already. For close focus, I stop down at least one step more. That is, the utmost sharpness of this lens depends also on the focus distance. At very close focussing, stopping down a bit more shows more improvement than it does at infinity, and as far as I can tell, this is not only depending on the depth of field (but no scientific measurements done).</p>

<p>But, as Craig said, for real macro work, the depth of field is more a worry that sharpness. These lenses are plenty sharp, and discussing "incredibly sharp" versus "just cut my finger so sharp" does seem to ignore that a photo has content too :-) Composition trumps sharpness any day. So, enjoy using the lens, at the aperture that suits your photo best!</p>

[tommyinca]

<p>Most folks talk about aperture with lens at infinity equivalent or other non-macro distances, rarely effective.</p>

<p>Aperture is only one of many variable that control how much details you can get. ie: Shutter speeds, Lighting, focus depth and diffraction inducted softness. IMHO, f5.6 is just one of many number you can use. Thats about it. </p>

 

[jaydesi]

<p>If you're focus stacking, then the aperture you use only has an effect on the number of shots you take to stack, for the most part. If you're doing single-shot macro, a smaller aperture like f/16 is likely to be more useful than f/5.6, simply for the DOF.</p>