Here’s a brief look at the Minolta AF 50mm F/1.7 lens. Scroll down for the review.
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Lens
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Minolta AF 50mm F/1 .7
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Box contents
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Front and rear caps and a users manual.
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Cost
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Find ’em on eBay for about $90-$150 as of 9/09
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Build quality
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OK to good
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Additional information
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Has neat built-in hood, .3″ (8mm) deep fully extended, but it does no good
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| Specifications below |
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Optical configuration
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6 elements in 5 groups
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Angle of view
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47° full frame, 32° 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, made for full frame. APS-C equivalent, 75mm
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Depth of field and focus scales?
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Yes and yes
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Minimum focus, image plane to subject
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18″ (450mm)
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Minimum focus, end of lens barrel to subject
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13.75″ (349mm)
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Hard stop at infinity focus?
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Yes
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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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49mm
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Filter ring rotates?
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No
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Distance encoder?
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No
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Max magnification
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0.15x
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Min. F/stop
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F/22
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Sony teleconverter compatible?
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No
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Dimensions W x L (my measurements)
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2.6″ x 1.5″ 66mm x 39mm
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Maximum extended length (my measurements)
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1.8″ (47mm), add .3″ (8mm) for hood extension.
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Weight bare (my scale)
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5.8oz (165g) 6.4oz (183g) with caps
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Requisite product shots.
All testing done with the Sony A 700, and A900. For full frame results, go to the bottom of the page. For a better understanding of my review methods and terminology, go here.
This page has a copy of the original owner’s manual.
The Minolta AF 50mm F/1.7 is a very compact lens, the smallest Minolta made in the day. This particular lens is a restyled version from the 1990s. It’s a “kit” type lens, and feels like it, meaning super light-weight. It doesn’t feel nearly as nice as the Sony 50mm F/1.4 lens, which costs over double the price of this one. Fit and finish are good, but plastic is used for everything but the glass it seems. It has a rather shiny black finish with rubber grip areas around the barrel and focus rings, and also sports a nifty built-in hood, which works by pulling on the plastic barrel around the front after you turn the focus to close-in, which allows you to grab it. The 28mm F/2.8 lens has the same feature. On top it has a focus distance window with ft/m in white, along with DOF hash marks. The lens is made in Japan. Filter size is 49mm.
Focusing. The little Minolta AF 50mm F/1.7 has a short focus throw, and auto-focuses quickly and accurately. Manual focusing is easy, and quick too, with a 1/4 turn from close-in to infinity. This lens has a sticky focus ring when near close focus, and from what I’ve been told from other sources, is a common problem. I think it has something to do with the built-in hood tolerances. Most people probably won’t be manually focusing with this lens anyways, so it’s not a deal killer.
Multi-coatings. It has the older Magenta/blue look. See comparison shot above.
Flare/ghosting. Flare, or veiling glare is similar to the Sony 50mm F/1.4, which is good, but watch the sun when it’s real close to, but not in the image. This lens has an odd, blue looking ghost, like half of a 7 blade aperture that shows up opposite of the sun when the sun is at the edge of, or in the image. It’s large and will mess up your shot, so pay attention. The ghosting control is not as good as the Sony 50mm F/1.4. This Minolta lens has a very small built-in lens hood that you slide out from around the front element, as described, and seen above, but it doesn’t do anything. Use your hand for keeping the sun out of the shot if possible.
Filter size, 49mm. Sony uses this size on the 28mm F/2.8 only.
Filter use. No noticeable additional vignetting using a regular filter.
Coma. Strong at F/1.7, good at F/2.5, gone by F/2.8.
Color looks the same as other Sony/Minolta lenses.
Close-up filter. works great, tested with a +4.
Bokeh is neutral to just so-so in my opinion. Not as good as the Sony 50mm F/1.4, see comps below.
Color fringing is light and poses no problems, it looks better wide open than the Sony 50mm F/1.4 does, but from F/1.7 and down, it’s about the same.
Distortion below.
Distortion is flat, which is good, so nothing to report here. About the same, or slightly less distortion than the Sony 50mm F/1.4.
Light fall-off.
Light fall-off is not a problem on an APS-C camera. It’s not noticeable in real pictures.
Random shots.
The top shots show how the lens handles the sun when inside the image. There always seems to be some purple somewhere in the image, even when the sun is centered. Veiling glare is strong when the sun is just outside the frame, use your hand to block the light, and you won’t have problems. The two shots at the bottom are comparisons of “Bokeh” or background blurbetween the Minolta AF 50mm F/1.7, and the Sony 50mm F/1.4. I like the look of the Sony better.
Veiling haze and CA wide open.
The images above are cropped from the centers. This lens is better wide open than the Sony 50mm F/1.4, but they even out at F/2. Just 1/3 of a stop makes a big difference. Don’t shoot at F/1.7 in broad daylight, save the large apertures for low light, where you won’t notice this stuff.
How sharp are the corners?
These crops are from the extreme bottom left corner. Things look rough here at F/1.7-2.8, then sharpen up gradually, peaking around F/8. They never really get sharp. See the comparison shots with the Sony 50mm F/1.4 towards the bottom.
How sharp are the centers if the image is enlarged to a staggering size?
The center sample crops above show F/1.7 to be soft, with veiling haze, but sharpens up with plenty of contrast at F/2. It appears the lens is at its sharpest at F/4-5.6. There isn’t a whole lot of change as you can see after F/2, and it’s only noticeable cropped and displayed side-by-side. This lens is pretty sharp at F/2-8, and is similar to the Sony 50mm F/1.4 in the centers, see comparison crops towards the bottom of the page.
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Bonus section!
Corner comparison crops. Read carefully. The Minolta 50mm F/1.7 lens crops are on the left, the Sony 50mm F/1.4 crops on the right.
It’s pretty clear the more expensive Sony 50mm F/1.4 lens is much sharper in the corners, at all apertures. I wouldn’t worry too much about it though, since it’s not very noticeable if you have an interesting subject.
Center comparison crops.
The Minolta 50mm F/1/7 is showing loss of contrast wide open, much the same as the Sony 50mm F/1.4 does at F/1.4. These two lenses are about equally sharp in the centers at F/2.8 and beyond.
Close focus sample.
Below, check out the close focus shot, click for a 100% cropped portion of the full image. The sample 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, 13.75″ or 349mm, measured from the front of the lens barrel to the subject.
This maximum magnification shot is sharp from F/4-8. This one was taken at F/5.6. It’s small, so if you want to get a little closer, screw on a +4 close up lens, like I did in this review.
My final thoughts.
The Minolta AF 50mm F/1.7 lens turned in a good performance. The good points are: compact, lightweight, low distortion, quick focusing, low color fringing, and is often found on eBay for just over a hundred bucks for a good copy, (original version), mine is a restyled version, but they’re the same optically according to the specs. The not-so-good points are; very soft corners with a wide aperture, and a sticky focus ring, neither one is a deal killer for the price.
This lens is a little long for an APS-C camera, so you’ll have to decide if you can live with an equivalent focal length of 75mm.
For full frame users; this lens performs mostly the same as the APS-C coverage, except for light fall-off. See paragraph below.
If you can afford to pay the extra money for the 50mm F/1.4, I’d just get that one, it’s sharper at the same apertures, from F/1.7-2.8, and offers 2/3 of a stop more light. If you’re strapped for cash, and just want a good low-light lens, this is a bargain. Don’t worry about the soft corners, you won’t notice them with good subjects.
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