Photo Jottings

Here’s a brief look at the Minolta AF 24mm F/2.8 lens.  Scroll down for the review.

Side shot

Front element much larger than 28mm F/2.8

Side shot with original hood.

Rear view

Left 28mm, right 24mm.

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 orignal owner’s manual.

The Minolta AF 24mm F/2.8 is a compact lens, about as small as you’re going to get.  Externally, it’s nearly identical to the Minolta 28mm F/2.8, the only thing different is the larger front element on the 24mm lens.  Build quality is very good.  This model is from the original 1985 design.  It has a satin black finish with white index marks along the focus distance window.  It also has an Infra-red focus index, the red dot on the aperture scale.  The lens says “Japan” so I’m assuming it’s made in Japan.  Focusing is quick and accurate, especially with the Sony A700.  Manual focusing is a chore, since the ring is slightly stepped down at the end of the barrel, plus the ring is very narrow and hard to manipulate with your fingers.

The lens is multi-coated with the mild magenta/green look.  The same as most other Minolta lenses from this era.

Filter size is 55mm.  Sharing this size in the Sony lineup are: 50mm F/1.4, 50mm F/2.8 macro, 55-200mm, 100mm F/2.8 macro, 75-300mm, 35mm F/1.4 and the 18-70 kit lens.

Filter use.   Regular filters cause no additional vignetting on full frame or APS-C cameras.

Lateral color fringing.  I see some red fringing on the sides.  Stopping down doesn’t help, but it’s not really noticeable unless you look at your pictures at 100%.  Very similar to the 28mm F/2.8 lenses.  Average control here.

Bokeh.  Depends, close at F/2.8, a little harsh, stopped down to F/4-5.6 it’s smoother, without the donuts.  Longer subject to background distances look good.  See crops below.

Color looks nearly the same as other Minolta/Sony lenses.

Coma.  Strong at F/2.8, better at F/4 and nearly gone at F/5.6.

Flare and ghosting.  With the sun inside the frame, you’ll see several blobs, followed by a golden arrow or two, depending on angle.  Similar to the Minolta 28mm F/2.8 lens.  The supplied hood really doesn’t do much, use your hand for best results with the sun outside the image.  See images below.

The top shots show what happens when you have the sun in the shot.  This lens holds up well to ghosting and flare.  There is very little flare with the sun just outside the frame, good control here.  When the sun is centered, left image, everything looks great.  With the sun offset, you’ll get a few small blobs of color opposite the sun, and a retrograde ghost, (blob on the other side of the sun).  Overall, the lens performed well here.  Bokeh examples on the bottom.  The F/2.8 shot looks busy, the F/4 shot is smoother, but you can see some heptagons from the straight bladed aperture occasionally in harsh, bright backgrounds.

Distortion. I notice a mild to moderate amount of barrel distortion, very similar to the Minolta 28mm F/2.8 lens reviewed here.

Barrel distortion.

light fall off or corner shading is well controlled on this lens.  On an aps-c size sensor there is a mild amount at F/2.8, but it’s very gradual, and blends nicely towards the center making it nearly invisible in real world pictures.  I gets better as you stop down.  The picture for the corners below shows light fall-off at F/2.8.

Next, we have the corner sharpness sample frame crops.  Go below to read the results.

This is the overall view of the corner crops below, above shot at F/2.8.

The corners sharpen up nicely as you stop the lens down.  The corners are pretty sharp at F/5.6 and beyond.  Don’t worry about soft corners at F/2.8, you wouldn’t be using F/2.8 in daylight anyways, and in low light it won’t show, so it’s really not a problem.

Center sample results.  Read below.

Above, look at the ridiculously boring pictures trying to split hairs on sharpness.  At F/2.8, it’s pretty sharp, but not the sharpest, which I think is at F/4-F/8, then a slight softening at F/11.  Keep in mind the sample crops are enlarged here to 100%, much larger than most people would normally observe.  Under normal circumstances, you’ll never see any soft centers.  There might be a bit less contrast at F/2.8 which can make it appear less sharp.Below, check out the close focus sample.  Click to see a 100% cropped portion of the full image, 175kb.  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, about 6″ or 152mm, measured from the front of the lens barrel to the subject.

F/5.6, click for larger image. 175kb

This doesn’t have much in the way of a macro ability, and you shouldn’t expect it to.  It is sharp though.  I also see some moire, so don’t shoot patterns like this from 6″ (152mm) away.  If you want a good macro on a lens with low magnification, use a close up filter like I did here.

Conclusion

APS-C users; the Minolta AF 24mm F/2.8 lens turned in a pretty good performance. It’s fairly sharp at F/2.8, and sharp all over at F/4 to F/8.  The corners are soft at F/2.8, but that’s no big deal as stated above.  It’s more useful than the 28mm on an APS-C camera; equaling 36mm, which is a nice walk around focal length in my opinion, better than the 42mm equivalent of the 28mm.  Current prices are running around $100-$200 on eBay, which is an excellent bargain if you can live within the focal length.  This lens will deliver sharp shots at F/2.8, for those that look at their images at 100% all day, use F/4.

For those that wannt a

Full frame users will notice some soft corners unless stopped down to F/5.6, and some heavy coma wide open, so watch the street scenes at night.  This is an excellent lens stopped down to F/8-11, and provides a small, light package compared to the zoom lenses starting at 24mm.  The only current ‘a’ mount lens of this focal length from Sony is the CZ 24/2.

The updated section below was added in November 2017, the original review was posted 5/2008.

The Minolta AF 24mm is still a good solid choice for interior work, or landscapes at F/8-11 using a full frame camera. For those using APS-C, the focal length would be about 36mm (in 135 film format).

Unfortunately, as we creep into 2018, Sony still has not produced a 24mm focal length ‘FE’ lens.

If you have an APS-C camera and want excellent optical qualities in this focal length, get the superb Sony CZ 24/1.8.  If you’re on a budget, check out the Sony pancake 16mm lens, which has the same coverage as a full frame 24mm lens.

This lens will  auto focus with the all Sony mirrorless cameras using the LA-EA4 adapter, or manual LA-EA3 here.

Check out the full size samples from the APS-C Sony A700 below, or go to the review and scroll to the bottom where I’ve added these samples, and made minor changes to the review; mostly page formatting etc.

F/2.8 F/4 F/5.6 F/8

Click yellow buttons for full size versions.

Check out the full frame samples from the Sony A900 below, or go to the review and scroll to the bottom where I’ve added these samples.  Note: these images were not intended to be viewed in their entirety, I was showing crops at the time, and this set was for the ‘corner’ crops in the full frame section of the review. The patio post and roof are very close, and not within the depth of field for this test set.

F/2.8 F/4 F/5.6 F/8 F/11

Click yellow buttons for full size versions.

That’s it for the update.