Minolta MD 100/4 vs Minolta AF 100/2.8 vs Tokina AT-X 90/2.5

[caspert79]

Just a little comparison between these lenses @ near infinity.

comparison by devoscasper, on Flickr

@ f/2.5/f/2.8: superior center sharpness of the Tokina compared to the Minolta AF, but very good corners from the Minolta AF compared to the Tokina.

@f/4: best corners by the Minolta MD, followed by the Minolta AF. But both don't match the obliterating center sharpness of the Tokina.

@f/5.6: Tokina's corners are about perfect now, as are the MD's. The Minolta AF's corners very good, just slightly behind. The Minolta AF's center seems slightly sharper than the MD's, but not significantly.

@f/8: Center of Minolta AF and Tokina seems equally sharp, the MD slightly behind. Corners all very good.

[eggplant]

An interesting performance turnout. I post these lens diagrams, but I do think they need to be taken with some context. I am looking to contextualise the MD 100mm f4 performance at f/4, really, because it looks good.

Maybe you could post some close ups, of a flat target - I wonder how it will hold up then.

The MD and Tokina go down to 1:2, the Minolta AF 1:1, the Minolta AF has floating elements (so adapter shimming important).

I wonder if the Tokina has floating elements. A long front extension when focused close, doesn't necessarily no floating elements- the Minolta AF does this.

The Minolta AF has an interesting structure, not just because of it's 'modernity' either.

Minolta AF 100mm f2.8

Both upscaled 2x with this (not perfect, but it will do here)

Tokina 90mm f/2.5

Minolta MD 100mm f/4

[caspert79]

[caspert79]

It always surprises me how good the Tokina is IRL. Here a few pictures I took this afternoon:

Wide open:
Tokatx9025J_4 by devoscasper, on Flickr

100% crop:
Tokatx9025J_4cornercrop by devoscasper, on Flickr

This image also taken wide open:
Tokatx9025J by devoscasper, on Flickr

100% crop from far corner:
Tokatx9025Jcornercrop by devoscasper, on Flickr

At this distance, corner performance wide open seems to be better than at infinity. No real softness here.

[caspert79]

OK, I just did a flat surface macro range comparison between the three lenses:

macrorangecomparison by devoscasper, on Flickr

In the f/2.5 / f/2.8 range, the Minolta AF clearly has better corners than the Tokina. It confirms the earlier near infinity and macro tests I did with the two lenses. Field curvature?
Unlike the earlier test in the macro range, the center image of the Tokina looks actually sharper than the Minolta. Look at the little white dots in the image. Impressive considering the f/2.5 aperture.

@f/4, the Minolta AF seems to have the best corners, followed by the MD. Because I didn't move the camera after carefully aligning it perpendicularly to the 20€ bill, differences in focal length and length of the optic, not exactly the same part of the bill is in the corner. The Tokina is behind in the corners, but center image still the sharpest.

@f/5.6, the corners of the Tokina become very good. Compare light blue lines between Min AF and Tokina. The Minolta AF seems sharper in the corners than the MD.

@f/8, all lenses show great performance. The Minolta AF and Tokina seem to slightly outperform the MD in the corners. The Tokina seems to be the sharpest lens in the center throughout the aperture range, by a hair.

CA's are not tested, but I think both Minolta's are a bit better in this regard than the Tokina, at least at wide apertures.

[Ernst Dinkla]