Photo Jottings

Minolta AF 100mm F/2

Front and rear caps, hood, and a users manual.

No longer available, but check used prices here.  At the time of this review, used prices are around $600-$900.

Very good

At the time of this review, Sony offers the Carl Zeiss 135mm F/1.8, which is more expensive, but performs better.

7 elements in 6 groups

24° full frame, 16° APS-C.

9 blades, circular.

Yes, made for full frame.   APS-C equivalent, 150mm

Yes and yes

40.5″  (1029mm)

35″  (889mm)

Yes, but off slightly

Yes

Yes

55mm

No

No

0.13x

F/32

No

2.65″ x 2.95″   68mm x 75mm

3.6″  (91mm)

16.7oz  (473g)  17.4oz (494g) with caps

Requisite product shots.

Side shot

Side shot with full focus extension

Backside

Front

All testing done with the Sony A700 12.2MP and Sony A900 24.6mp cameras.  See full frame results at the bottom of the review.  For information on my lens review methods and terminology, go here.

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 hereof 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. 

 

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.

 

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.

Minor pincushion distortion.

 

Distortion isn’t bad at all, and only shows slight pincushion if you look closely.

 

Light fall-off.

 

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 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.

 

Center crop from F/2

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.

 

 

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.

 

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.

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.

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.