105mm Lens — What It Actually Does

105mm sits close enough to 100mm that the two focal lengths are frequently discussed together, but 105mm has carved out its own specific reputation, largely through a handful of especially well-regarded Nikkor lens designs built at exactly this focal length — most notably a long-running 105mm f/2.8 macro line prized for its optical correction, and a separate 105mm f/1.4 portrait prime known for exceptionally smooth background rendering, sometimes nicknamed for its distinctive, almost otherworldly out-of-focus character.

The equivalents below track closely with 100mm's, since five millimeters makes little practical difference once cropped onto a smaller sensor.

Portrait Use: A Genuinely Distinct Rendering From 85mm

Where 85mm is photography's most commonly cited portrait length, 105mm pushes the compression and background separation noticeably further, at the cost of requiring more working distance from the subject. Dedicated fast 105mm portrait primes (f/1.4 and similar) are specifically sought after by photographers who want more dramatic background compression than 85mm delivers, and are willing to trade the closer, more conversational working distance 85mm allows for it — a deliberate, specialist choice rather than a default recommendation the way 85mm often is.

Macro Use and the Extra Working Distance Over 100mm

As a macro focal length, 105mm offers a modest but genuine working-distance advantage over 100mm at true 1:1 magnification — a small amount of extra breathing room that matters for particularly skittish subjects or awkward lighting setups, though the difference between the two focal lengths at macro distances is considerably smaller than the difference their normal-distance telephoto field of view suggests. Photographers choosing between a 100mm and 105mm macro lens are more often deciding based on a specific manufacturer's optical design and price point than on this small working-distance difference alone.

Depth of Field at Macro Distances

As with any true macro lens at 1:1 magnification, depth of field at 105mm collapses to an extremely thin plane regardless of aperture, driven primarily by the extreme magnification itself rather than focal length or f-number in their normal-distance sense — focus stacking remains the standard technique for rendering an entire small subject sharply at these distances, the same practical reality every macro-capable focal length on this site shares.

Depth of Field at Normal Portrait Distances

At typical portrait distances and a wide aperture like f/1.4 or f/2.8, 105mm produces genuinely dramatic subject-background separation, often more pronounced than 85mm achieves at the same f-number, simply as a consequence of the longer real focal length.

Nikon has built multiple dedicated 105mm macro lenses across both F-mount and Z-mount systems specifically at this focal length rather than the more common 100mm standard, a deliberate brand-specific choice carried forward across several lens generations. Some 105mm lenses, particularly older manual-focus designs, were specifically prized for a distinctive, soft-edged bokeh rendering that later autofocus redesigns deliberately corrected away in pursuit of clinical sharpness instead. A deliberate brand-level design tradition rather than a technical requirement. A real, lasting design lineage.

Nikon's current Z-mount 105mm f/1.4 also draws attention purely as a portrait prime independent of any macro capability, a genuinely different market position from the focal length's more common macro association.