Nikon 105mm f/2.5 AI Lens Review

Background

Considered by most Nikon lens aficionados as one of the must have manual focus lenses, I took the leap and snagged this lens up from a local camera store.

1/400, f/4, ISO 200 - PEN-F

Handling/Size/Weight

This lens covers the FX sensor size.  Given that fact you might think that a 105mm f/2.5 lens should be rather on the large size.  That is not the case with this lens.

An all metal build gives the lens some heft to it, but I would not consider the lens to be "heavy".

Used on the Nikon Df and adapted to the Olympus PEN-F, the balance feels right on either camera, although it is a little more lens heavy on the PEN-F, as one might expect.

Being an AI (aperture index) lens, setting up the Df in the menus to accept the lens allows the aperture index lever to accurately report the cameras settings in the EXIF data.

1/125, f/4, ISO 1000 - PEN-F

1/200, f/2.5, ISO 200 - PEN-F

Image Quality

Some people think that older lens designs, even prime lenses, are not as good as the modern equivalents.  There might be some truth to that statement if we get into a "measurebating" analysis.  I, however, do not fully agree.  While it might be true that on paper one lens may be sharper than another, there is more to a lens than the overall sharpness.  My belief is that there is a threshold of "sharp enough" or acceptable sharpness that is good enough for me.  The 105mm/2.5 AI lens certainly falls into that category and then some.

If we look at the lens at f/2.5, this is probably where the lens is at its weakest.  Even with that, the wide open performance is still plenty acceptable.  Stopped down even a little bit to f/4 and it is very sharp.

I find that I like the rendering of the lens as well.

1/125, f/2.8, ISO 3200 - PEN-F

1/160, f/2.5, ISO 200 - PEN-F

Focusing

The focus ring on my copy is very smooth with a hard stop at infinity.  I'm able to go from closest focus to infinity with one turn.  The front element does move in and out when turning the focus ring.

The focus throw is great, giving one the ability to be very accurate with minute adjustments.

1/125, f/4, ISO 1000 - PEN-F

Bottom Line

Having this as my first experience with a manual focus lens was a great choice.  It ticked all the boxes for size, portability, image quality and ease of focusing.