Minolta AF 28-135mm F/4-4.5 Review

Here’s a brief look at the Minolta AF 28-135mm F/4-4.5 zoom lens. Scroll down for the main review.

Lens	Minolta AF 28-135mm F4-/4.5
Box contents	Front and rear caps, users manual, no hood came with this lens.
Cost	Available on eBay at the time of this review for around $350, depending on condition.
Build quality	Good, to very good
Additional information	Original Minolta AF lens design. Quite expensive back in its day.
Specifications below
Optical configuration	16 elements in 13 groups
Angle of view	75°-18° full frame, 50°-12° APS-C.
Aperture	7 blades, straight
Full frame and APS-C	Yes, full frame and APS-C. APS-C equivalent, 42-202.5mm
Depth of field and focus scales?	Distance window, and IR index marks at 28mm, 35mm, 50mm, 70mm, 100mm, and 135mm.
Minimum focus, image plane to subject	9.6″ (244mm) Using macro switch
Minimum focus, end of lens barrel to subject	3.4″ (86mm) Using macro switch
Hard stop at infinity focus?	Yes
Length changes when focusing?	No
Focus ring turns in AF?	Yes
Filter size	72mm
Filter ring rotates?	Yes
Distance encoder?	No
Max magnification	0.09x, or 0.25x with macro switch engaged
Min. F/stop	F/22-25 or F/27 using half stop Exposure steps.
Sony teleconverter compatible?	No
Length changes when zooming?	Yes
Dimensions WxL (my measurements)	2.95″ x 4.3″ 75mm x 109mm widest at filter ring
Maximum extended length (my measurements)	5.75″ (146mm)
Weight bare (my scale)	26.6oz (753g) 27.5oz (780g) with caps

Requisite product shots.

Front element

Backside

Side view, fully extended

Side view, fully drawn-in

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 28-135mm F/4-4.5 was one of the first few lenses Minolta came out with when they switched over to the AF mount around 1985. I think it was a pretty expensive lens back in the day. It’s built mostly of metal, the only plastic visible is the zoom and focus rings, therefore, it’s heavy, and weights more than the Minolta AF 70-210mm F/4.

This lens has a couple of features not normally encountered on the average Minolta AF lens. It has a large 72mm filter thread, and for some reason was not designed to accommodate a standard Minolta AF hood. Also, the focus ring is at the very back of the lens by the mount. Another rather abnormal feature is the macro switch, (also found on a few other Minolta AF lenses) which gives a maximum reproduction ratio of 0.25x coming slightly before 28mm, (instead of the usual long-end 135mm), that’s why you have to get so close to the subject. to see what I’m talking about, look at the product shot above. There is no auto-focus ability when the macro switch is engaged, that’s by design, and I don’t know why. Without the macro switch engaged, the close focus ability is a paltry 0.09x! A minor item of note; the minimum aperture at the telephoto end reads F/25 using one-third exposure steps, or F/27 using half stops.

The lens color is standard original AF Minolta satin black, shinier than the original Sony black. The zoom ring is lined with ribbed rubber, which slowly turns white with age. A thorough cleaning with a damp sponge and mild soap brings out the original look. Also try a tooth brush as a last resort for getting the dirt out along the ribs. The zoom ring tension is a little loose in my opinion, and wants to creep out all the way if you leave it much past 28mm and point it down, at 28mm it seems to stay put. There are focal length marks at 28, 35mm, 50mm, 70mm, 100mm and 135mm. It has a focus distance window, with a whopping six(!) 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 the common purple/green look.

The Minolta AF 28-135mm lens is described in various internet chat rooms as the “secret handshake” lens, because long ago, a couple of idiots got suckered into believing Minolta produced this lens, and sold it at cost as a “thank you” to the loyal Minolta customers of the day. Unfortunately, there are still a bunch of suckers that believe that today thanks to chat rooms. Minolta wasn’t in the business of handing out stuff for nothing in the 1980s, they didn’t have to. Now days, young people are used to electronics companies, (cable, radio, cell phones) handing out stuff for free, but it isn’t free, you have to sign a contract that amounts to a fewhundred thousand dollars to get the stuff. Minolta produced excellent, unique products that stood on their own, and people were happy to pay the price. Did Sony give away the “Walkman” back in the day?

Focusing. Manual focusing is a chore on this lens. The focusing ring is at the rear of the lens, and is rather narrow, both of which make it hard to grip, though it turns easily with one finger. These lenses were never really meant to be focused manually. Manual focusing takes about 1/4 turn from Close-in to infinity, and doesn’t add any length to the lens. Auto-focusing is not very fast, but adequate, and is mostly accurate, especially with the A900.

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 with your hand to keep the contrast up in your shots. Oddly, this lens was not designed with a mount for the standard Minolta AF hood, and didn’t come with a hood when new, I don’t know why.

Color fringing (CA). Above average control. Look for mild amounts of lateral color fringing (mostly magenta is noticeable) on APS-C cameras, and slightly more for full frame coverage. See full frame section for sample crop. Axial color fringing is minimal, stopping down gets rid of this type; if you stare at your images at 100% on your computer screen, you may see a little at F/4-5.6, by F/8 it’s not noticeable.

Bokeh. Harsh looking at wide angle, slightly better at the long end. Look below for sample crops.

Color. Same as other Minolta lenses.

Close up filter. N/A

Coma. A slight amount with APS-C cameras across a good portion of the focal range at F/4, one stop down and it’s gone. Full frame shows a little more, see below.

Regular filters cause no additional light fall-off problems on APS-C cameras, but do affect full frame cameras at 28mm, see example at bottom.

Filter size is 72mm. This size isn’t too popular with Sony, and only the 20mm F/2.8, 135mm STF, and Carl Zeiss 85mm F/1.4 use it.

Distortion. You’ll notice moderate barrel distortion at the wide end, becoming flat around 40-45mm, then pincushion distortion increasing out to 135mm using an APS-C camera. Of course, full frame coverage shows more distortion. Check out the images below.

Distortion examples directly below.

28mm, moderate barrel distortion.

Mild pincushion at 135mm.

Lens flare/ghosting examples

28mm F/5.6, massive ghosting with sun just out of image	28mm F/11 sun in shot

135mm F/5.6, sun just in picture	135mm F/5.6 sun out of shot

28mm F/4	28mm F/5.6

135mm F/4.5	135mm F/5.6

coma 28mm, F/4	coma 28mm, F/5.6

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 to, or in the frame. Shooting the sun when it’s in the center of the image stopped down results in a dull disk around the sun. Things don’t look much better at the long end. Overall, I’d day the results above are poor by today’s wide-angle zoom standards, but normal for yesterdays wide-angle zooms.

Bokeh, (cropped) looks harsh at wide angle, and somewhat better towards the long end slightly stopped down. Heptagons clearly visible at wide angle, F/4. Typical bokeh performance for the original Minolta AF zooms.

Coma. Bottom row. Just a small amount using a wide open aperture through most of the focal lengths. One stop down and things look good. Look at the beautiful 14 pointed stars from the 7 bladed straight aperture!

Aperture/focal length guide for the Minolta AF 28-135mm F/4-4.5 This lens zooms from 28mm to 40mm staying at F/4, at 45mm, you’ll get F/4.5. Look below for guide.

Maximum aperture	F/4	F/4.5
Range	28mm-40mm	45mm-135mm

Light fall-off.

See the crops below. Light fall-off or corner shading is not noticeable in real pictures at any focal length or aperture using an APS-C camera.

28mm F/4	28mm F/5.6

135mm F/4.5	135mm F/5.6

Center and corner sharpness.

Below are crops from the image centers and corners at 28mm.

F/4 center	F/4 corner

F/5.6 center	F/5.6 corner

F/8 center	F/8 corner

F/11 center	F/11 corner

The 28mm center crops show very sharp at F/4, and stay sharp all the way to F/11. The corners are a different story. At F/4, the corners are quite soft, but improve much one stop down at F/5.6. Corner sharpness continues to improve as you stop down, but never quite matches the centers. Still a very good job overall.

Below, crops from the 50mm centers and corners.

F/4.5 center	F/4.5 corner

F/5.6 center	F/5.6 corner

F/8 center	F/8 corner

F/11 center	F/11 corner

At 50mm, the centers look very good at F/4.5, and appear as sharp wide open as they do stopped down. The corners nearly match the centers in sharpness at F/8-11.

Below are centers and corners from 135mm.

F/4.5 center	F/4.5 corner

F/5.6 center	F/5.6 corner

F/8 center	F/8 corner

F/11 center	F/11 corner

The 135mm center crops show improvement by closing the aperture a couple of stops, and F/8 seem sharpest. The corners are close, but not quite as sharp as the centers at the same aperture. The sharpest corner shots seems to come at F/11 at this length. The F/11 corners are as sharp as the F/11 centers, which is very good performance, especially for a 1980s zoom. You see some lateral color fringing, exacerbated by veiling haze at F/4.5-5.6. Exposure differences are from light fall-off.

Let’s check out the macro capabilities of this lens.

Below, check out the 100% cropped portion (308kb) of the full image. The sample shot was taken with the Sony A 700 12.2MP camera. The subject is a standard US stamp, 0.87″x 1.0″ or 22mm x 25mm. Also, note the macro shot was taken as close to the subject as focusing allowed; in this case a very short 3.4″ (86mm), 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 new postage stamp. F/8 was the sharpest at close focus, but F/4 looked very good also. The maximum reproduction size comes at the wide end, before 28mm, that’s why you have to get so close to the subject. As a side note; the “1996” on the bottom left of the stamp measures a mere 1mm wide.

As close as you can get. F/8. Click for larger image.

Full frame section next.

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/4	28mm F/4 with UV filter attached

28mm F/5.6	28mm F/8

135mm F/4.5	135mm F/5.6

Light fall-off is definitely stronger with full frame coverage. I see moderate levels at 28mm, with a hard fall-off wide open, diminishing greatly just one stop down. Check out the sample of additional light fall-off as a result of using a regular type UV filter at 28mm, It’s a little more noticeable than normal, that’s why I’m showing it. At the long end, there’s mild 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/4. It’s noticeable, but not distracting in my opinion. In bright sunny conditions like this, you don’t have to use F/4, use F/5.6 or smaller instead, and you’ll have no dark corners to worry about.

Lateral color fringing.

This full frame 28mm, F/11 crop shows color fringing, which is a little stronger with a full frame camera. Look at the magenta and cyan colors around the rocks, tree trunks to the left, and car tire. It’s noticeable if you look for it, but not bad by any stretch. This crops comes from the last 700-800 pixels on the left side of the image as you would see it on your computer screen at full size.

28mm corner samples next.

F/4	F/5.6

F/8	F/8 from center

F/11	F/16

The 28mm full frame corners look pretty soft wide open, and things don’t change much until F/8-11. 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.

50mm corners below.

F/4.5	F/5.6

F/8	F/8 from center

F/11	F/16

Moving on to the 50mm corners, which show better than the wide angle crops at all apertures. The corners sharpen up nicely by F/8, and are almost, but not quite as sharp as the centers. At F/16, the corners start to degrade due to diffraction. Exposure differences are from light fall-off.

135mm corners.

F/4.5	F/5.6

F/8	F/8 from center

F/11	F/16

The 135mm corners show some veiling haze wide open, which makes the lateral color fringing more apparent. Stopping down the aperture sharpens the corners up, and hides some of the color fringing. This kind of color fringing really doesn’t go away as you stop down, it just seems that way when the image is going from soft to sharp; (axial color fringing goes away as you stop down, but this lens exhibits low levels). F/11-16 corners seem to be the sharpest. Exposure differences are from light fall-off.

Distortion next.

Moderate barrel distortion @28mm on A900

Moderate pincushion distortion @ 135mm on A900

There is moderate to strong barrel distortion at the 28mm end, and moderate pincushion distortion as you zoom in. The distortion curves here are gradual across the frame, and are easy to correct in post processing.

Coma results below.

28mm F/4	28mm F/5.6

Coma is not really an issue with this lens. At F/4-5.6 there is mild coma at the extreme corners at most focal lengths, but one stop down and it all but goes away.

Conclusion.

The Minolta AF 28-135mm F/4-4.5 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. This lens was also quite expensive when introduced, and came with odd features, as mentioned above. Sony has a current lens (Minolta designed) similar in focal length, the 24-105mm F/3.5-4.5, but it doesn’t perform as well overall.

Focusing accuracy is quite good, most likely the result of the low F/4 maximum aperture. It’s also not speedy, but typical for the day. Color fringing as well as light fall-off are kept to a minimum, and both are controlled well, with average, to above average performance. Flare and ghosting are strong, and by today’s standards would be considered poor, but are average for a 1980s Minolta AF zoom. Bokeh or background blur is also not very smooth, but the few items mentioned should not overshadow the most impressive characteristic, the overall sharpness of this lens, which is excellent. If Sony put in a circular aperture, SSM-not SAM, and some modern coatings to try and eliminate some of the ghosting (like they did on the 50mm F/1.4) this lens would probably get a “G” designation and sell like hot cakes!

For APS-C users; If you can live within the equivalent focal length of 42-202.5, then I’d buy one without delay, especially you landscape shooters out there. At F/5.6-8, it’s nearly a perfect lens if sharpness is a primary concern. There’s only one real downer, which is ghosting. When the sun is in or near the image at wide angle, you’d better pay attention and try and block the sun with your hand, otherwise, you’ll be sorry. If you can’t live without real wide-angle coverage, then I’d probably go with the CZ 16-80mm, or Sony 16-105mm.

Full frame users; the corners are soft at wide angle, but are about average for a wide-angle zoom, even comparing them to today’s modern lenses. Stopping down helps out, and at mid-range to telephoto the corners are almost as sharp as the centers, that’s very good performance, especially for full frame coverage. Color fringing and light fall-off are also more noticeable as opposed to APS-C performance, but aren’t distracting at all.

I really like the Minolta AF 28-135mm lens, and would prefer it over the Sony 24-105mm F/3.5-4.5. At the time of this review, I think the Minolta AF 28-135mm F/4-4.5 is the best walk-around lens for a Sony full frame camera. Be sure and check out the Tamron 28-75mm F/2.8 review, I’d get this lens over the others if it meets your focal length desires.

Photo Jottings

Minolta AF 28-135mm F/4-4.5 Review

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