Desperatly trying to set up a "correct" comparison between the Nikkor 105/2.5 AIS and the Tamron 90/2.5 (manual focus, the earlier 52B version, filter size 49mm). Not because of different focal lengths : keeping the framing identical is the best way to perform a fair comparison if FLs are not too different. The problem is to get exactly the same focus, and even using LV that is difficult.
First impressions from less-than-perfect series shot with Df and D800 :
- similar contrast. Originally I thought the Tamron was less contrasty ; this is probably due to higher flare propensity. In the present case I shot against a wall at different angles and with different contraptions in front, light sources being diffuse. The Tamron has a more complex optical formula and both lenses have coatings from the same generation, which might explain the difference outdoors.
- similar light transmission and vignetting
- 90/2.5 colors are slightly warmer
- 90/2.5 has a higher resolution, especially at wide apertures. Stopped down, their are about the same in the center, but the Tamron remains better in the corners.
- 90/2.5 has the flatter field (probably explaining, in part, the better corner performance)
- Different bokeh : Nikkor is smoother behind (no "edging"), Tamron is smoother in front
- 90/2.5 displays much less LoCA, but is not LoCA-free
- Size, weight, handling, manufacturing quality are very good in both cases. Only downside is that orientation of the focus scale is reversed on the Tamron compared to all Nikkors.
Note : the above concerns short distance shooting (about 2 m) !
Bottom line : Df huggers should seriously consider getting the Tamron 90/2.5... especially if close-ups or macro work (down to 1:1 with extender) is likely to occur.
Caveats : I need to establish further comparisons (long distance and against the light).