|
Requisite product shots.
|
| Box and contents |
|
| Front |
|
| Backside |
|
| Full focus extention |
|
| Left 28mm F/2, right 28mm F/2.8 |
|
| Left 28mm F/2, right 28mm F/2.8 |
|
| Left 28mm F/2, right 28mm F/2.8 |
This page has a copy of the original owner's manual. The Minolta AF 28mm F/2 is a compact lens,
although slightly longer and heavier than the much less expensive Minolta F/2.8 version, but you might not notice the difference
unless viewed side-by-side. Build quality is very good. It has a gloss black finish with ribbed rubber inserts
around most of the circumference. It has a focus distance window with ft and m in different colors along with DOF hash
marks. It also has an infra-red focus index mark, the red dot on the aperture scale. The lens is made in Japan.
This lens has a short focus throw, and it focuses very quickly and accurately using the A700 or
A900. There's a tiny bit of slop on the focus ring if you wiggle it by hand when engaged, and none in actual MF use.
Manually, the ring can be somewhat difficult to manipulate with a finger and thumb, especially with the hood attached.
A quarter turn gets you from close focus to infinity. The focus ring turns in auto-focus mode, but thankfully, not the
filter ring. This lens is very similar to the Minolta AF 28mm F/2.8 as mentioned above, and I'll be making some comparisons throughout the review. This lens has
the typical multi-coatings from the 1980s and doesn't resist flare and ghosting as
well as the F/2.8 version, see sample shots below. You'll see a lot of blue/purple blobs and/or an
arc depending on angle and aperture. The sun doesn't have to be in the image to make a mess of things, so be sure and
block any intense light sources which can cause havoc with your pictures. It comes with a nice plastic hood that has
a flat finish on the inside surface, unfortunately, as is the case with most wide angle lenses, the hood doesn't do much good,
use your hand for keeping the sun out of the shot if possible. Filter size is 55mm.
The F/2.8 version uses 49mm. Filter use. A regular filter
causes slight additional vignetting at F/2 on a full frame camera, none on APS-C. Coma
is horrendous at F/2, but much improved by F/2.8, and completely gone by F/4. See sample crops below.
Color
looks the same as other Sony/Minolta lenses. Close-up filter. Works
great, see results here of Minolta 28mm F/2.8 lens using a +4. Bokeh is busy at F/2, but smooths
out nicely at F/2.8. See crops below.
Lateral color fringing is present,
but not very apparent unless you shoot bright white subjects flanked by dark areas--and--look at your images greatly enlarged
on your computer screen. I mostly came upon red and cyan, though red is usually more noticeable. Stopping down
won't help with this type of CA. This lens is about average in this department. See the sample
image below. Random samples below.
|
Flare and ghosting full image
|
Color fringing crop
|
|
|
|
Flare and ghosting example using the full image. As you can see, the sun isn't in view, but
it still tends to make a mess of things. As I said above, you should use your hand to block the sun. On the right
is a crop showing color fringing. It isn't too bad, you'll see mostly red/cyan though red is obviously more
visible. Don't worry about this issue as it's only noticeable upon very close inspection.
Coma
samples below.
|
F/2
|
F/2.8
|
|
|
|
Coma is super bad at F/2, and extends into the image almost half way, the worst I've ever seen, but
good news, it clears up rather quickly one stop down at F/2.8 and is completely gone at F/4. The above crops were take
from the lower left corner. Veiling haze below.
|
F/2
|
F/2.8
|
|
|
|
These crops show veiling haze, (normal with wide angle, fast lenses used wide open) visible wide open
at F/2, but mostly disappears by F/2.5, I show F/2.8 above. It's really not bad at all, and no sane person would
shoot F/2 in broad daylight as I've done here. Distortion below.
|
| Barrel distortion. |
Barrel distortion isn't bad at all, and looks very similar to the Minolta AF 28mm F/2.8 version.
Light fall-off.
|
F/2
|
F/2.8
|
|
|
|
Light fall-off or corner darkening is moderate at F/2. It blends well into the center of
the image so it's not distracting in real pictures. By F/2.8 it's gone.
Bokeh
examples below.
|
F/2
|
F/2.8
|
|
|
|
Bokeh at F/2 look a little busy to me, mostly from the hard edges. I prefer the stopped down look,
which is much smoother. Images are 100% cropped samples from the center. Overall view of
corner crops, and light falloff at F/2. Shot at F/2, no adjustments. Light fall-off in real images is barely noticeable on a cropped sensor
camera. The scene above is also the whole image for the cropped corner shots below. I wonder
how sharp the corners are?
|
F/2
|
F/2.8
|
|
|
|
|
F/4
|
F/5.6
|
|
|
|
These crops are from the extreme lower left corner. Things look good here at F/2, except for the
haze, but there's still plenty of detail. F/2.8 is where things clear up, though I think the sharpest corners come
at F/4. The exposure differences are from light fall-off at F/2-2.8. How sharp are the centers
if the image is enlarged to a staggering size?
|
F/2
|
F/2.8
|
|
|
|
|
F/4
|
F/5.6
|
|
|
|
Center sample results.
The center sample crops above show F/2 to be
a little soft, mostly due to spherical aberration, but just one stop down and this baby is tack sharp at F/2.8. There
isn't any sharpness advantage by stopping down past that. Keep in mind you wouldn't want to use F/2 in bright sunny
conditions as I've done here for test purposes only. In low light conditions, which is the proper use of F/2, you wouldn't
see any soft corners or centers. This lens is very sharp from F/2.8 to F11, F/16 is slightly soft due to diffraction.
Close focus sample. Below, check out the close focus shot, a 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, 7.6" or 193mm, measured from the front of the
lens barrel to the subject.
|
| Click for larger image F/4 |
This maximum magnification shot is sharp, but quite small, and nearly identical to the Minolta AF 28mm F/2.8 macro. If you're using this lens properly, you won't care about macro type shots. If you want to add
a little "zing" to a close up, add a +4 close up lens, like I did in this review.
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
|
F/2
|
F/2.8
|
|
|
|
|
F/4
|
F/5.6
|
|
|
|
Light fall-off is worse than the APS-C crops shown earlier. At F/2 it's actually heavy, and
noticeable in real shots. Full image from A900 below. The dark corners are very noticeable here, which actually cover a good portion of the frame, and nearly
requires exposure compensation, but lord almighty, don't shoot at F/2 in broad daylight!! This picture was F/2 at
1/6400sec.
Corner samples next.
|
F/2
|
F/2.8
|
|
|
|
|
F/4
|
F/5.6
|
|
|
|
|
F/8
|
F/11
|
|
|
|
The corners are softer than the APS-C crops show. Don't sweat this too much as a normal
landscape shot would be at least F/5.6, and low light shots would probably hide soft corners depending on subject matter.
The centers of these crops are about 250 pixels from the image borders, as you can see, the right upper areas are sharper
as you approach F/4 and smaller. It does appear that F/11 produces the sharpest corners, but not by much. The
exposure differences are from light fall-off.
|
| Barrel distortion on A900 |
There is very slightly more barrel distortion, but the only way to notice it is to toggle between the
two images. Coma results with full frame.
This is coma on the A900. You need an extra stop to get rid of coma with the A900 as opposed to
an APS-C body. The crops are taken from near the edge of the image but coma can be seen at least 2000 pixels in from
the corners towards the center at F/2, 600 pixels at F/2.8, and about 300 pixels at F/4. |
My final thoughts. The Minolta AF 28mm F/2 lens turned
in a very good performance. Good points are: compact, lightweight, low distortion, quick focusing and very sharp from
F/2.8 to F/11, even on full frame bodies. The corners sharpen up nicely about two stops down. Flare and ghosting
can be strong when the sun is near the image, as I've said above, use your hand to block stray light. The Minolta
AF 28mm F/2 lens would be great in an inside low-light environment such as a museum or entertainment setting. While
this lens begs to be used at F/2.8 on an APS-C body where it's nearly flawless, there are some disadvantages for full
frame users, such as; more light fall-off, softer corners and the dreaded coma, which is strong until F/4, so watch the street
scenes at night, and if you take the chance, try and steer clear of F/2, where coma is so bad it may ruin your shots.
F/2.8 is much better. This is a low-light lens, and is much more expensive than the F/2.8
version, by a good 5x. This lens is very impressive at F/2 to F/2.8 (except for coma). If you don't think
you'll be needing to shoot at those apertures, buy the F/2.8 model and walk away with several hundred dollars in savings
to spend on something you'll use more often. One more point to ponder; on an APS-C body, you'll be getting the
equivalent of 42mm, so if you want true wide angle for those cameras, you'll have to find something in the range of 18mm-24mm,
unfortunately, you won't be seeing an F/2 lens in that range anytime soon.
|
