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Requisite product shots.
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| Side shot |
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| Side shot with full focus extension |
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| Backside |
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| Front |
This page has a copy of the original owner's manual. The Minolta AF 100mm F/2 is a compact lens,
about the same size (but a little heavier) as the Sony 24-105mm F/3.5-4.5 lens. Build quality is very good. It
has a gloss black finish with ribbed rubber inserts around most of the circumference. It has a focus distance window
with ft and m in different colors along with DOF hash marks. It also has an infra-red focus index mark, the red dot
on the aperture scale. The lens is made in Japan, and dates to the late 1980s. Filter size is 55mm. This
lens has a normal to long focus throw, and focuses a little slow, but mostly accurately using the A700 or A900. There
seems to be a bit of front-focus at long distances, and back-focus at short distances, but not noticeable past F/2.8.
There's a tiny bit of slop on the focus ring if you wiggle it by hand when engaged, and none in actual MF use. Manually,
the ring is pretty easy to manipulate with a finger and thumb. Over a third of a turn gets you from close focus to infinity,
with the overall length of the lens increasing and extra 16mm for focus extension. The focus ring turns in auto-focus
mode, but thankfully, not the filter ring. My copy of this lens is pretty scratched up, so instead
of spending days in photoshop re-doing the images pixel-by-pixel, I darkened them up to hide the damage. Optically though,
it's in great shape. This lens has the typical multi-coatings from the 1980s,
and the color is predominately golden. You'll see a lot of green/magenta blobs and/or arcs depending
on angle and aperture. The sun doesn't have to be in the image to cause heavy veiling glare, so be sure and block any
intense light sources which can cause havoc with your pictures. This lens came with a hood originally, but my sample
is missing that part. I tried a few modern Sony 55mm hoods, and found the best fit was the hood from the Sony 50mm F/1.4
lens. I don't think is has the correct flanges, but it holds tight. Also try the Sony 75-300mm F/4.5-5.6 hood.
It fits ok.
Filter size is 55mm. This is also Sony's most popular
size. Filter use. A regular filter causes no additional vignetting
on a full frame, or APS-C camera. Coma. None on an APS-C camera, but
full frame has a very small amount at F/2. See sample crops below. Color looks
the same as other Sony/Minolta lenses. Close-up filter. Works ok,
with a little contrast loss. A +2 or +4 would help out if you want a better close focus shot since this lens has a small
reproduction ration of 0.13x. See results here of a Minolta 28mm F/2.8 lens using a +4. Bokeh looks somewhat busy when
the background is close to the subject at medium distances. Overall, I found (in most images) the background blur to
be fairly smooth, and very similar to the Sony 100mm F/2.8 macro lens. See crops below.
Axial
color fringing is present, especially at F/2, (and typical of 1980s lens designs), but not very apparent unless you
shoot bright white subjects flanked by dark areas--and--look at your images greatly enlarged on your computer screen.
I mostly came upon magenta and cyan, though magenta is usually more noticeable. Stopping down gets rid of this type
of CA. Lateral color fringing (occurring along the sides) is not very noticeable, and control seems above average here.
See the sample images below. Random samples below.
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Big green blob, F/5.6
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Magenta blobs at F/5.6
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Ghosting examples using the full image. The left sunset shot shows a large, bright green blob, which
is obviously very noticeable. There're also some red arcs/arrows which are not so noticeable. The right shot
shows a more intense sun, with different colored ghosts. This is typical of first generation Minolta AF lens ghosting
performance. There are no problems with the sun centered in the image. Veiling glare is strong anywhere close
to the sun. Use your hand as a hood, which will eliminate most of this problem.
Comparison to the Sony 100mm F/2.8 macro.
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Minolta AF 100mm F/2, @F/2
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Sony 100mm F/2.8 macro, @F/2.8
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Minolta AF 100mm F/2, @F/2.8
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Sony 100mm F/2.8 macro, @F/2.8
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I thought I'd throw in a comparison of the Minolta 100mm F/2, and the one stop slower Sony 100mm
F/2.8 macro. The Minolta is clearly the sharpest at F/2.8, bottom row. I'd also say the Minolta 100mm is about
as sharp at F/2 as the Sony 100mm macro is at F/2.8, though with obvious axial color fringing, the Sony has almost none, (top
row). If you want a fast medium telephoto lens, the Minolta AF 100mm F/2 is better, although the close focus ability
is poor. All exposure values are the same. The top and bottom Sony 100mm F/2.8 shots are the same. Distortion
below.
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| Minor pincushion distortion. |
Distortion isn't bad at all, and only shows slight pincushion if you look closely.
Light
fall-off.
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F/2
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F/2.8
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Light fall-off or corner darkening is moderate at F/2. It blends well into the center of
the image so it's not distracting in real pictures. By F/2.8 it's gone.
Bokeh
examples below.
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F/2
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F/2.8
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Bokeh is fairly smooth, nothing special. I thought it would be a little smoother for some reason.
Images are 100% cropped samples from the center. Veiling haze and color fringing.
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| Center crop from F/2 |
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| center crop at F/2.8 |
You can see from the top image that color fringing and haze are noticeable at F/2. Luckily, the
image clears up nicely at F/2.8. All axial CA is gone at F/5.6. Center and corner crops side-by-side.
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F/2 from center
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F/2 from corner
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F/2.8 from center
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F/2.8 from corner
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F/4 from center
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F/4 from corner
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F/5.6 from center
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F/5.6 from corner
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I've put the center and corner crops side-by-side this time, and the lens produces sharp corners,
as expected with an APS-C camera. It looks like the centers sharpen up fully at F/4, and the corners at F/5.6.
The F/2 crops look a little fuzzy, due to veiling haze, but they're showing quite a bit of detail, I'd say about as
much as the Sony 100mm Macro lens shows at F/2.8, see crops above. I see some lateral color fringing in the corner crops,
which doesn't go away as you stop down. It's not bad at all, and only noticeable with huge enlargements. Close focus sample. Below, check out the close focus shot, a 100% cropped
portion of the full image. The sample shot was taken with the Sony A 700 12.2mp camera. The subject is a standard US stamp, 1"x 3/4" or 25.4mm x 19mm. Also, note the macro
shot was taken as close to the subject as focusing allowed; In this case a long 35" or 889mm, measured from the front
of the lens barrel to the subject.
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| Maximum reproduction, no larger image, F/5.6 |
This maximum magnification shot is sharp, but quite small, with a ratio of 0.13x. I chose the F/5.6 shot.
The F/2.8 shot was just as sharp, but didn't look as good due to the axial color fringing.
Full frame results using the Sony A900 below. Check out
the differences when using a film or full frame camera below. I'm only pointing out the noticeable issues as compared
to the APS-C bodies, so if I don't show it here, the results are not significantly different enough to warrant posting
an additional set of images in this section. Light fall-off
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F/2
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F/2.8
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Light fall-off is handled well, and isn't much of a problem wide open; one stop down and the corners
brighten up to nearly match the central area. Full image from A900 below. The slightly dark corners visible in the gray shot at F/2 are hardly noticeable in a real picture.
The image above with a slim DOF was taken at F/2, 1/6400 sec at ISO 200.
Corner
samples next.
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F/2
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F/2.8
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F/4
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F/5.6 from center
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The corners are pretty sharp, and don't look any different from the centers at each aperture.
I show a F/5.6 shot from the center on the bottom right crop.
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| Very mild pincushion distortion on A900 |
There is minor pincushion distortion, about the same as the APS-C crop shows, which suggests the lens
is producing less distortion at closer focusing distances: I had to take the A900 shot at a closer distance to fit the window
in the frame than the A700 due to the crop factor.
Coma results with full frame.
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F/2
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F/2.8
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This is coma on the A900. It's not bad at all, and wouldn't be noticeable unless viewed
at huge sizes. One stop down to F/2.8, and coma disappears. |
My final thoughts. The Minolta AF 100mm F/2 lens turned
in a very good performance. Good points are: compact, low distortion, and very sharp from F/2.8 to F/11. The corners
are about as sharp as the centers. Color fringing is strong wide open, but looks much better one stop down. Flare
and ghosting can be strong when the sun is near (or in) the image, as I've said above, use your hand to block stray light,
that's easy to do on a small telephoto lens. Used prices for the Minolta AF
100mm F/2 run roughly the same as the Sony 100mm F/2.8 macro, which is a stop slower. I'd definitely buy the Minolta
F/2 if I wanted a good medium telephoto lens, and available light, hand-held shooting was the primary purpose. This
lens is very impressive from F/2 to F/2.8, and would make a good portrait lens. I would actually prefer this lens to
the much more expensive, but one stop faster CZ 85mm f/1.4, the main reason being; I prefer moving subjects, and the DOF is too thin at F/1.4 for reliable sharp focus points.
If you don't think you'll be needing to shoot at those apertures, stick to the slower, less expensive and more useful zoom
models. For you people with a fistful of cash, buy the better Carl Zeiss 135mm F/1.8, which focuses quicker and more accurately, and is better at controlling flare and ghosting. It also has less color
fringing and haze wide open, and produces great shots at F/1.8. |
