Here’s a brief look at the Minolta AF 24-50mm F/4 zoom lens. Scroll down for the main review.
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Lens
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Minolta AF 24-50mm F/4
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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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In the range of $110-$160 used.
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Build quality
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Good
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Additional information
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Frequently found on eBay.
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| Specifications below |
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Optical configuration
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7 elements in 7 groups
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Angle of view
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84°-47° full frame, 56°-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, full frame and APS-C. APS-C equivalent, 36-75mm
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Depth of field and focus scales?
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Distance window, and IR marks at 50mm, 35mm, 28mm, and 24mm.
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Minimum focus, image plane to subject
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13.75″ (350mm)
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Minimum focus, end of lens barrel to subject
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9″ (229mm)
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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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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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0.18x
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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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Length changes when zooming?
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Yes
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Dimensions WxL (my measurements)
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2.7″ x 2.4″ 69mm x 60mm
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Maximum extended length (my measurements)
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2.8″ (71mm)
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Weight bare (my scale)
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10.0oz (284g) 10.8oz (306g) with caps
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Requisite product shots.
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| Lens and hood |
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| Front element. |
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| Side view, maximum length (24mm) including focus extention |
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| Backside mount. |
The Sony A700 and Sony A900 was used for this review. For full frame results, go to the bottom of the page. For a better understanding of my review methods and terminology, go here.
The Minolta AF 24-50mm F/4 wide-mid zoom lens (made in Japan) is made for full frame and film cameras. This particular version comes from the mid 1980s, and is very similar in appearance and operation to the Minolta 35-70mm F/4 lens. It is short (at 35mm) and light, even when extended out, and extends fully at the wide end, 24mm, which is a bit unusual, most lenses are just the opposite. It has a constant fast aperture of F/4. Currently, Sony has no equivalent lens. The color is satin black, shinier than the Sony black. Fit and finish are good. The zoom ring is lightly dampened, with no slop, and about right in my opinion. It has a focus distance window along with four red infra-red focus index marks at 50mm, 35mm, 28mm, and 24mm, which is also the same as the focal length marks on the lens barrel; duh! The EXIF data matches up with the focal length marks. The lens is multi-coated and has the typical older-style magenta cast. I can’t find any info about aspherical, “ED” elements, or special coatings used.
Auto-focusing is quick and fairly accurate. It seems to miss occasionally. It’s only off a tiny bit, It may be just my lens, I bought it used, but it seems to be in great shape. When you turn the camera on after mounting the lens you hear a “slap” which is the camera focus motor tugging through screws at the lens to ensure a proper coupling. Manual focusing takes just over 1/3 turn from Close-in to infinity, with some noticeable slop, but not bad. The filter ring extends and rotates as you focus, (not to be confused with the focus ring) which is at the end of the lens barrel, so watch your grads and polarizers, and to make matters a little more difficult, the focus ring is very narrow and slightly stepped down from the lens barrel, making it hard to grab. You really shouldn’t be using manual focus anyways, it’s not necessary with this lens. The closest focusing distance from lens barrel to subject is about 9″ or 229mm.
Lens flare/ghosting. Poor. The sample below was taken with the sun not even close to the image. The hood doesn’t do any good in this situation, use your hand for good control. Ghosting on this lens at all zoom settings is poor, but it isn’t the worst lens I’ve ever tested.
Color fringing. Very good control here. I saw none in normal picture taking.
Bokeh. Poor, see crops below. Looks like concentric circles shooting target with bullseye at wide angle, just like the Minolta 35-70mm F/4. 50mm is round, but has a harsh outline. The crops are a full 100%, so don’t get too worried over this in real life.
Color. Similar to Sony lenses.
Coma. Massive at F/4 from 24mm-35mm, at F/5.6 it’s gone, surprisingly! At 50mm and F/4, it’s light to moderate, one stop down and nothing. See small crop below.
Close-up filter. Works great, If you don’t know what this is, see review here.
Filter size is 55mm. This is a very popular size, and Sony uses it on at least seven of its lenses.
Filter use. Regular filters cause slight additional vignetting on full frame at 24mm, F/4. None on APS-C cameras.
Distortion. See below. Barrel at 24mm, but almost mild. Distortion is flat at 28mm, then towards the long end it turns to mild pincushion. Good control here.
Distortion examples
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| 24mm, mild to moderate barrel distortion. |
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| Mild pincushion at 50mm. |
Random samples
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Ghosting, 24mm F/4
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Coma at 28mm F/4
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Bokeh at 24mm F/4
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Bokeh at 50mm F/4
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Extreme example of ghosting above, but shows actual results near the sun. Poor control at any zoom setting. Use your hand instead of the supplied hood. When the sun is centered in the image, there’s a large ring and disc that may spoil the picture. Bokeh examples above, not good at all, and very similar to the Minolta AF 35-70mm F/4. The aperture looks round at F/4 and 50mm, but has a harsh outline. This is not a big deal unless you plan on enlarging prints to the extreme and have a close, out of focus background. The top right shot is coma, which occurs in the corners of (mainly) wide angle lenses at large apertures. The points of light should appear round, not as comet trails or badminton birdies, or shuttlecocks to you experts. This is one of the worst examples I’ve seen. The good thing is; one stop down and it’s mostly gone.
Light fall-off.
Light fall-off or corner shading is very mild at F/4 from 24mm to 50mm, so don’t worry about this. See crops below.
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24mm F/4
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50mm F/4
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Center and corner sharpness.
Below are crops from the image centers at 24mm.
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24mm F/4
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24mm F/5.6
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Now the 24mm corner crops.
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24mm F/4
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24mm F/5.6
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The 24mm center crops show very little improvement by stopping down, that’s good since they’re pretty sharp. The 24mm corners do make a difference by stopping down to F/5.6, sharpening up a hair more at F/8.
Below, look at the 50mm center crops.
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50mm F/4
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50mm F/5.6
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50mm corner crops below.
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50mm F/4
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50mm F/5.6
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On to the 50mm centers, where the results are pretty much the same as the wide angle shots, sharp at F/4, then maybe a hair sharper one stop down, but only visible blown way up on a computer screen. I see a tiny bit of veiling haze at F/4 at all focal lengths, but not enough to worry about. The corners are helped by closing the aperture one stop, that’s all the better it gets. At F/4 and near 50mm, you’ll see soft sides, covering well over half the frame, but the centers are pretty sharp. It’s much better at F/5.6, and the best at F/8. This issue may not be indicative of all 24-50mm F/4 lenses, there could be sample variations. This is the kind of performance I’d expect from a Sigma lens.
Let’s check out the macro capabilities of this lens.
Below, check out the sample and click the picture to see a 100% cropped portion of the full image, (195kb file). 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 short 9″ (229mm), measured from the front of the lens barrel to the subject.
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| As close as you can get macro, at F/5.6. |
The close focus shot is sharp, but rather small, with a magnification of .18x. The image is sharpest at F/5.6, good job!
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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
Light fall-off is still pretty mild on a full frame camera. At both ends F/4 shows moderate levels, but it blends smoothly towards the center. One stop down and it’s mild. It doesn’t seem to clear up entirely, even at F/11. Don’t fret, as it hardly shows in the real shot below taken at 24mm, F/4.
Full image from A900 below.
This full scene shows how the light fall-off from 24mm, F/4 isn’t as bad as the crops above show. As I’ve said before, you wouldn’t have to use F/4 in an outdoor, broad daylight scene anyhow! The small amount you see above is easily cleaned up with vignetting sliders in some photo editing software.
24mm corner samples next.
The corners at 24mm are very soft using a full frame camera, and take an extra stop (as opposed to APS-C) to sharpen up, close to F/11. These crops come from the extreme corners, things look good at F/8. As I said above in the APS-C section, the sides are soft wide open, you’d better stop down to at least F/8 for landscape or architectural type shots.
50mm corners below.
The 50mm corners sharpen up more quickly than the wide angle crops, looking decent at F/8, though they’re still not really sharp, even at F/11.
Distortion next.
There is moderate distortion at both ends on the A900, but not enough to be noticeable in regular shots unless you’ve got straight lines near the periphery.
Coma results with full frame.
This is coma on the A900. It’s very Strong and noticeable in the corners at F/4 at wide angle, but is controlled better at F/5.6. The 50mm end exhibits coma also, one stop down and it’s almost gone. The 100% crops in this A900 section are from the extreme corners, and are a portion of the original image. The complete image printed out as you might see it on your screen would measure 65″ (1.65m) wide using the A900!
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Conclusion.
APS-C users. This lens turned in a decent performance. Good points are; sharp centers at F/4 over the entire range, no need for stopping down in normal use. The corners sharpen up nicely one stop down or so, light fall-off is controlled well, and color fringing is not an issue. Unfortunately, there are a couple of downers to ponder, like soft image periphery near the end of the zoom, where over half the frame is soft, though it clears up one or two stops down, depending on length, and the pesky flare/ghosting problems, though a simple solution would be to watch your shots and block light with your hand, so I wouldn’t really consider this a problem, just don’t shoot with the sun in the image if possible. Bokeh is bad, though most people won’t notice this unless examining their images at 100% on a computer screen. This lens works very well on APS-C cameras, were the focal range is in decent territory, 36-75mm equivalent, unlike the similar (but better performing) Minolta 35-70mm F/4, equivalent to 52-105mm. Also note; the latter has a much better macro if that’s your thing.
In all honesty, There are more useful lenses in the Sony/Minolta lineup with an APS-C camera in my opinion, such as the 18-70mm kit lens, or, if you’re willing to spend more money, the CZ 16-80mm or 16-105mm.
Full frame users. I’m not sure I could recommend this little lens. It’s sharp in the centers, unfortunately, unless stopped down, the sides of the image are soft as I said above, and now exacerbated by the full frame coverage. Low light performance at F/4 is good in the centers, but any sharp points of light near the corners will wreak havoc (coma) on the image Outside in sunny weather, add in some extra flare and ghosting when the sun is close to, or in the frame. This lens was good back in the film days when people saw most of their shots printed at 4×6 or 8×10 where this stuff isn’t really noticeable. For the same price (or slightly more) you should be able to grab a Minolta AF 24mm F/2.8 if you plan on using wide most of the time, or for a little more money, try a Minolta or Sony 24-105mm F/3.5-4.5, which has a much more useful zoom range.