Here's a brief look at the Minolta AF 28-85mm F/3.5-4.5
zoom lens. Scroll down for the main review.
Lens
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Minolta AF 28-85mm F3.5-/4.5
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Box contents
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Front and rear caps, hood, and users manual.
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Cost
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Available on eBay for around $100, depending on condition.
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Build quality
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Good, to very good
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Additional information
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This is the original mid 1980s model, the newer (early 90s) version has a different zoom ring pattern and a rubber grip
around the focus ring, but optically is the same.
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Specifications below
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Optical configuration
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13 elements in 10 groups
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Angle of view
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75°-29° full frame, 50°-19° APS-C.
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Aperture
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7 blades, straight
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Full frame and APS-C
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Yes, full frame and APS-C. APS-C equivalent, 42-127mm
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Depth of field and focus scales?
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Distance window, and IR marks at 28mm, 35mm, 50mm, 70mm and 85mm.
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Minimum focus, image plane to subject
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9.8" (250mm)
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Minimum focus, end of lens barrel to subject
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3.6" (91mm)
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Hard stop at infinity focus?
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Yes, but off on my copy
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Length changes when focusing?
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Yes
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Focus ring turns in AF?
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Yes
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Filter size
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55mm
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Filter ring rotates?
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Yes
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Distance encoder?
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No
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Max magnification
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0.12x, 0.25x with macro switch
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Min. F/stop
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F/22-29
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Sony teleconverter compatible?
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No
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Length changes when zooming?
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Yes
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Dimensions WxL (my measurements)
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2.75" x 3.4" 70mm x 86mm
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Maximum extended length (my measurements)
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4.4" (111mm) includes 2mm focus extension
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Weight bare (my scale)
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17.5oz (495g) 18.2oz (517g) with caps
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Requisite product shots.

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Side shot, drawn in, included hood not shown. |

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Front element. |

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Side view, fully extended |

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Backside mount. |
The Sony A700 and A900 were used for this review. For full frame results, go to the bottom of the page. For a better understanding of
terms and methods used in this review, go here. To view the original owner's manual, go here. The Minolta AF 28-85mm F/3.5-4.5 was one of the first few lenses Minolta came out with
when they switched over to the AF mount around 1985. I think it retailed for over $200 when introduced, which was expensive
back then. It's built mostly of metal, the only plastic visible is the zoom ring, therefore, it's heavy, more so than
the CZ 16-80mm, or Sony 16-105mm, but has the same basic dimensions. This lens works a little
differently than most, in two ways. It extends out and is longest when set to 28mm, and is fully retracted at 70mm,
at 85mm it moves out about 1mm. This is the same type of action as the old kit lens from Minolta, (35-70mm F/4).
Another rather abnormal feature is the macro switch, (also found on the 35-70mm F/4 just mentioned) which gives a maximum
reproduction ratio of 0.25x at 28mm, (instead of the usual long-end 85mm), that's why you have to get so close to the subject.
Also, there is no auto-focus ability when the macro switch is engaged, that's by design, and I don't know why. The
lens color is standard AF Minolta satin black, shinier than the Sony black. The zoom ring tension is about right in
my opinion, and doesn't want to creep out when you walk. There're focal length marks at 28, 35mm, 50mm, 70mm, and 85mm.
It has a focus distance window, with a whopping five(!) infra-red focus index marks corresponding to the focal length index
marks. The EXIF data matches up with the focal length marks. I can't find any info about "ED" elements
or special coatings used. This lens is multi-coated and has an uncommon bluish/purple look. Auto-focusing
speed is average. It seems to be accurate, except for the infinity mark, where it's off a hair, focus just less than
infinity for the sharpest pictures at real infinity, (your copy may vary). Manual focusing takes just over 1/3 turn
from Close-in to infinity, and will extend the barrel about 2mm at close focus. As usual, the focus ring is very narrow
and hard to grip. These lenses were never really meant to be focused manually.
Lens flare/ghosting. About average control for a 1980s zoom, but well below average for
a twenty-first century zoom. I see multi-color blobs if the sun is at the edge, or inside the image. Look below
for examples. Veiling glare seems a little strong, so prepare to block the sun or other super-bright light source to
keep the contrast up in your shots. As usual, the hood really doesn't help much, use your hand for best control.
This lens comes with a small, kit lens type hood, which is worthless.
Color fringing (CA).
Average control. I see a very small amount of axial color fringing when using wide apertures all focal lengths, though
no big deal as this type of CA goes away as you stop down. Look for moderate amounts of lateral color fringing, (red)
on APS-C cameras. Full frame coverage yields slightly stronger lateral color fringing results, with a bluish cast in
the extreme corners, see samples below.
Bokeh. Harsh looking at all focal
lengths and apertures, and similar to the Minolta 35-70mm F/4 lens. Look below for sample crops. Color.
Same as other Minolta lenses. Close up filter. Works great, a +4 tested.
Use in macro mode for best results. Coma. A slight amount
with APS-C cameras at wide angle and F/3.5, one stop down and it's gone. It's much more pronounced with full
frame coverage, see photos below. Regular filters cause no problems on APS-C cameras,
but do affect full frame cameras at 28mm, see example at bottom. Filter size is
55mm. This is a popular size with Sony, which uses it on the 50mm F/1.4, 35mm F/1.4, 50mm macro, 100mm macro,
75-300mm, 18-70mm, and the 55-200mm. Distortion. You'll notice
mild to moderate barrel distortion at the wide end, and mild to moderate pincushion distortion zoomed out to 85mm using an
APS-C camera. Of course, full frame coverage shows more distortion. Check out the images below.
Distortion
examples

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28mm, moderate barrel distortion. |

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Mild to moderate pincushion at 85mm. |
Lens flare/ghosting examples
28mm F/5.6, blue and purple ghosts
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85mm F/8 big red blob
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28mm F/5.6, A900, sun out of picture
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28mm F/8 sun centered, with blue outer ring and center smudge
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28mm F/3.5
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28mm F/5.6
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85mm F/4.5
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85mm F/5.6
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coma 28mm, F/3.5
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coma 28mm, F/5.6
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I see multi-colored blobs when the sun is close to the edge of the frame, or inside the image. This
lens has a somewhat heavy amount of veiling glare when the sun is close, or in the frame. Shooting the sun when it's
in the center of the image results in a faint ring in the image, near the borders. Overall, I'd day the results
above are strong for todays zooms, but normal for yesterdays zooms. Bokeh,
(cropped) looks harsh at all focal lengths and apertures. Coma. Bottom
row. Just a small amount at wide angle, with a wide open aperture. A stop down or so and things look good.
Aperture/focal length guide for the Minolta AF 28-85mm F/3.5-4.5
This lens has overlapping numbers, for instance; you can get F/3.5 or F/4 at 35mm, depending on tiny movements of the zoom
ring, this is quite common. Look below for guide.
Maximum aperture
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F/3.5
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F/4
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F/4.5
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Range
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28mm-35mm
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35mm-60mm
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60mm-85mm
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Light fall-off. See the crops below. Light fall-off or corner
shading doesn't show up at wide angle. Towards the long end there's a mild to moderate amount at F/4.5, but
it blends nicely towards the middle. This is not noticeable in actual pictures.
28mm F/3.5
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28mm F/5.6
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85mm F/4.5
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85mm F/5.6
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Center and corner sharpness.
Below are crops from the image
centers at 28mm.
28mm F/3.5
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28mm F/4.5
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28mm F/5.6
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28mm F/8
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Image centers at 28mm, F/3.5 are a little soft, but sharpen up nicely at F/4.5. I'd say F/5.6
is the sharpest for real pictures, and F/11 starts to soften due to diffraction. Now the
28mm corner crops.
28mm F/3.5
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28mm F/4.5
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28mm F/5.6
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28mm F/5.6 from center
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28mm F/8
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28mm F/11
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The 28mm corner crops show minor improvement by closing the aperture one stop, and that's about
as good as it gets. I show a center crop at F/5.6 for comparison. Overall, not very good results for an APS-C
camera. Also notice the red color fringing along the rock edge. This kind of color fringing occurs along the image
periphery, and doesn't get better by stopping down. Notice the center crop has no color fringing. Below,
look at the 85mm centers.
85mm F/4.5
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85mm F/5.6
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85mm F/8
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85mm F/11
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The 85mm center crops show high veiling haze at F/4.5, which is a bit unusual, but improves at F/5.6.
The image sharpens up nicely at F/8-11. I'd normally expect better results at F/5.6 than what I have here, but oh
well. 85mm corners below.
85mm F/4.5
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85mm F/5.6
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85mm F/8
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85mm F/11
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The corners at 85mm aren't much different than the centers, meaning they're soft at large apertures, and
best at F/8-11.
Let's check out the macro capabilities of this
lens.
Below, check out the 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 very short 3.6" (91mm), measured from the front
of the lens barrel to the subject. This lens has a large reproduction size of
0.25x with the macro switch engaged, and produced a sharp close shot of the usual postage stamp. F/8 was the sharpest
at close focus. The maximum reproduction size comes at the wide end, 28mm, that's why you have to get so close to
the subject.

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As close as you can get. F/8. Click for larger image. |
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
28mm F/3.5
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28mm F/3.5 with UV filter attached
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28mm F/4.5
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28mm F/5.6
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85mm F/4.5
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85mm F/5.6
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Light fall-off is definitely stronger with full frame coverage. I see moderate levels at 28mm,
with a hard fall-off wide open, diminishing as you stop down. Check out the sample of additional light fall-off as a
result of using a regular type UV filter, It's a little more noticeable than normal, that's why I'm showing it.
At the long end, there's mild to moderate light fall-off, but it blends evenly towards the center and doesn't show
in regular pictures. Full image from A900 below.
This boring full scene shows light fall-off from 28mm, F/3.5. It's noticeable, but not too
bad. In bright sunny conditions like this, you don't have to use F/3.5, so don't worry about this.
28mm corner samples next.
28mm F/3.5
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28mm F/4.5
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28mm F/5.6
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28mm F/5.6 from center
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28mm F/8
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28mm F/11
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The 28mm full frame corners look rough wide open, and things don't change much until F/11.
I threw in a center shot comparison, just to show you how soft the extreme corners are. The size differences between
the center and corners are not from moving in, they were shot from the same spot, that's just the nature of wide angle
lenses, and how they render objects in the corners. Also notice the strong color fringing, which doesn't go away
as you stop down. 85mm corners below.
F/4.5
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F/5.6
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F/8
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F/5.6 from center
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Again, the 85mm corners don't look much different than the centers, and react about the same to stopping
down. Notice the blueish color fringing along the white wall on the left, and along the top, but nothing in the center
crop. Exposure differences are from light fall-off. Distortion next.

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Odd barrel distortion @28mm on A900 |

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Pincushion distortion @ 85mm on A900 |
There is moderate to strong barrel distortion at the 28mm end, and moderate to strong pincushion distortion
as you zoom in. The wide angle barrel distortion is complex. It rises in the center, and falls off quickly about
3/4 of the way out, then is nearly flat at the ends, which makes corrections harder in post processing. The pincushion
distortion is a gradual curve across the frame, and would be easy to correct. Coma results below.
28mm F/3.5
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28mm F/5.6
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35mm F/3.5
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35mm F/5.6
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Coma is a problem with a fully open aperture towards the wide end with full frame coverage. Closing
the aperture a stop or so helps greatly. Don't worry about this unless you shoot pictures with bright points of
light at the corners, in low light. Conclusion. The
Minolta AF 28-85mm F/3.5-4.5 is one of the original Minolta AF lenses from the mid 1980s, and is now over 20 years old.
It's well built, with a minimum of plastic components, which makes it heavy for its size. Overall operation is smooth,
and accurate, except for the infinity focus issue mentioned earlier. Optically speaking, this lens
is just OK, nothing really stands out as being good or better than other zooms in this range. The macro shot is sharp,
with a large reproduction ratio, but with newer designed lenses, it's only about average. This lens shows it's
age, especially in flare and ghosting, where control is poor. If you keep it out of the sun, and stopped down one or
two stops, this lens is actually pretty good, but so are most other lenses. For APS-C users;
I'd pass on this lens, the focal range is not very desirable in my opinion, equalling 42-127mm. I would much rather
carry around the standard Sony kit lens (18-70mm), it's smaller, lighter and far better at controlling flare and ghosting. If you have more money, get the CZ 16-80mm, or Sony 16-105mm. I'd even try a Minolta 24-105mm F/3.5-4.5 which might be a little more money, but will perform better, I reviewed
the Sony version here. Full frame users; the corners are pretty soft, especially at wide angle,
color fringing and light fall-off are much more noticeable with the extra coverage. I'd skip this lens for the Sony
or Minolta 24-105mm F/3.5-4.5, which performs better overall, though the macro isn't as large. Bottom
line; this lens was probably considered pretty good back in the day. Fortunately, that day has passed and there are
better choices out there now. Although this lens may sell for less than $100 depending on condition, it's not worth
it if you have the lenses mentioned above.
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