|
English
Language Teaching in Japan
| |
|
 |
A new lens: Minolta 28mm f2.8 |
|
This is a little look at
analysing a new lens, and getting to know it better. If you are
considering purchasing new lens, then the following should give you a
good idea of what to look for in lenses, even for Canon, Nikon, and
other brands. |
|
Background
The Minolta camera company began in 1928,
and has been producing both lenses and cameras since that time. In 1985,
Minolta changed their system to the Auto-Focus (AF) system, which
included evolving their existing lenses. Today, Sony continues the AF
system as the 'Alpha' system, whilst carrying on the tradition of
improving on top quality lenses with successful refinements. This
Minolta 28mm f2.8 lens is from that heritage, designed many years
before, continuously refined, and this was made perhaps in the 1980's.
This lens is the Minolta 28mm f2.8, not the
28mm f2. The difference being that the f2 is slightly better in
performance according to Photodo users. It was also made for the 35mm
film format, making it mostly compatible with the "Full Format" sensors
(see "Made for Film", below), and has the equivalent of 42mm using the
APS-C sensor, losing its wide angle advantage.
|
 |
 |
| The
Minolta 28mm f2.8 |
For
more talk on these lenses |
First test shots (all handheld)
Key terms have been highlighted, for
convenience.
| Picture 1. Pictures two and
three come from this first. This picture, in the first three hundred
or so, is fairly typical of the photos produced. Notice now, that
there is no vignetting.
This lens was originally designed for the 35mm film cameras, but
this test used the APS-C sensor on the Konica Minolta Alpha Sweet.
That means, the image isn't as wide as it is on 35mm, and the image
appears only on the "sweet spot", cutting out any vignetting, if
present. (f9, 1/125, iso100) |
1.
 |
| Picture 2,
takes a closer look (at a 100% crop), we can see some noise in a,
which is the fault of the camera. Also, b shows slight, just
very slight Chromatic
Aberration (CA). This lens
seems to display some magenta CA, which, being magenta, is something
I'd never seen in a lens before; usually, CA is purple. |
2.
 |
| Picture 3
shows that
barrel distortion
is present, even of other subjects and at more clement angles. 28mm
is wide, and early wide lenses were prone to this, and still, cheap
lenses suffer this today. The distortion is slight, but noticeable. |
3.
 |
| Picture 4
shows a real lack luster performance. Here, the lens allows the
sensor
to be easily over saturated.
(f5.6, 1/800, iso800) |
4.
 |
| Picture 5
does not show any barrel distortion, colours look great, depth of field looks
natural, but some purple CA appears on the power poles on the right
hand side. The sky, again has lost its colour from sensor over
saturation. (f11, 1/125, iso400) |
5.
 |
| Picture 6
shows fantastic colour
representation, no
detectable barrel distortion, nor any other problem. There is some
noise, but that's the problem of the camera. (f10, 1/200, iso100) |
6.
 |
| Picture 7
shows great colour representation, perhaps there might be some barrel
distortion, but if there is, it's pleasantly effective. (f5.6,
1/125, iso200) |
7.
 |
| Picture 8
is in studio, using studio flashes. The lens forces you to come
close to the subject, which at that age, you do need to be close.
Surprisingly, no barrel distortion present, despite the proximity of
the camera to the subject. (f13, 1/125, iso100) |
8.
 |
| Picture 9. Being a wide angle
lens, it gives a lot of atmosphere and context to your picture. It
focuses fast, and being a prime lens, gives good quality of clarity
and low light performance (no direct sunlight here). (f6.3, 1/125,
iso200) |
9.
 |
| Picture 10.
In the Christmas-Tree Bokeh Test (a test I invented), we can see the
shape of the out-of-focus areas, showing us the
bokeh
of this lens. We can see it gives an heptagonal shape, perhaps due
to its seven aperture blades, and some outlining of these. What we
should see is smooth circles and no outlining. |
10. |
11.
 |
12.
 |
13.
 |
| 11. Aperture at f2.8. |
12. Aperture at about
half. It can be seen that the blades do not for a circle, but a
polygon, which is shown in bokeh (see picture 10, above). |
13. Aperture at f22 |
14.
 |
15.
 |
16.
 |
| 14. Left Minolta 50mm
1.4, compared to 28mm 2.8. |
15. The
front element is slightly bulbous, and the hand grip is practical
and easy to keep lint free. |
16.
Internal lens hood fully extended. As seen in picture 15, there is a
thumb hold to pull out the hood. It does not sit flush, as like the
Minolta 50mm 1.4, 1985 release. |
Comments
This lens was bought second hand for 14,000
yen (about USD$120-ish). The Minolta 28mm f2 is at least double that,
but according to Photodo users, there's but a hair's breadth between them.
Though, I think I can guess the differences are to do with slight
Chromatic Aberration, slight barrel distortion, and bokeh quality.
Specifications:
Its minimum focusing distance is 30cm, and infinity is just beyond the
3m range, though despite the short focusing distance, it's not a macro (see here for more
information on macros). Since it's wide-ish, at 28mm (on 35mm film),
it cannot get that zoom advantage to act macro-like. This makes it good
for regular family photos with busy children. On
the f2.8 version of the 28mm the filter screw size is 49mm, 6mm smaller
than other standard lenses in the Minolta / Sony line up, more said
below in "Filters". 185 grams makes it very light, very short, and
very nice to move about with. It's fast to focus, see more in
"Flexibility".
Made for film:
As said, this lens was made for 35mm film format, which means that the
surface isn't 'optimised' to transmit light and colour well to a digital
sensor. New equivalent lenses do have a coating which improves colour
transmission to the sensor. Also, this lens will work on Full Format
sensors, with normal 28mm wide angle performance. Though, on an APS-C
sensor (28mm sized frame), it has an equivalent of about 42mm, giving
almost approximately the normal human field of view. It also takes advantage of
the "sweet spot" of the APS-C sensor, so any vignetting is not present,
though it may be present on a full
frame sensor and film.
Focusing: This is also considered as
it can be taken as a sign of build quality. The manual focusing ring is
firm, not tight, and can allow for very fine manual focusing. Also, in
auto focus mode, it can be fairly quick.
Money Talks:
The f2.8 is less than half the price of the supposedly slightly higher quality f2, but still has great colour, fairly
good control of other aspects of where other lenses go wrong. Though,
there is some barrel distortion, but it is kind of expected since this is a wide
lens. What's not expected is magenta colour Chromatic Aberration (CA),
though the CA is very slight, especially compared to today's new lenses.
Flexibility:
Most lenses don't perform well at their maximum nor minimum f-stops.
I've avoided using f2.8, and didn't use f22; I mostly stayed between
f3.5 and f14, just to avoid any possible CA and loss of quality in bokeh.
I haven't check these extremes at this time, but I assume that it'll
give mediocre results; though f2.8 is great to have in low light
situations. For photographing children, its quick focusing, and short
focusing range (3m before infinity) makes it really easy to get good
photos of constantly moving, unpredictable children.
Filters: The front screw mount element does not rotate, which
is great for mounting filters, especially swiveling polarisers. The
manual focus ring is rather narrow, and your fingers could rub against
any Lee or Cokin filters. The front screw mount is 49mm, where most
other front elements are 55mm in the Sony / Minolta range, this means
you'd have to have either adapters or a second range of filters.
Quality Controls:
It's not a bad lens, surprisingly, for a wide angle lens it does perform
better than expected. Conversely, I guess, it should have been expected
to do well as it is a prime lens, which should give better performance than
almost any
zoom.
Final Rating:
Well, what does a number mean, anyway? I've learnt it's limitations, its
weaknesses and strengths, and feel more confident in knowing when to use
this lens, and when not. Though, in short, I'm glad I got it.
|
Your Comments
Share them here on the
Photography & Art forums, or at
Digital Dynax. |
From
Bill: "The 28/2.8 is a nice lens for the
money. The 28/2 is MUCH better. If you want a 28mm prime, get the
F/2, especially if shooting on an APS-C format camera. The 28/2 is
incredibly sharp, even wide open, over the entire sensor on the
a700. On full frame, there are distortions at the edges." |
References
Photodo, (30th Dec 2008) Minolta 28mm f2.8,
http://www.photodo.com/product_757.html
Photodo, (30th Dec 2008) Minolta 28mm f2,
http://www.photodo.com/product_756.html
Also see
Photodo, (30th Dec 2008) Photographic lens
specification, guides, discussion and reviews,
http://www.photodo.com/
Photozone, (30th Dec 2008) Sony Alpha APS-C
Lens Tests,
http://photozone.de/sony-alpha-aps-c-lens-tests
|
|
| Examples |
|
| |
Some of
these are available at
for purchase. |
 |
< Japanese
Fishing boats at New Year, decorated with the names of the boats or their
owners. F7.1, 1/200, iso100. Minolta 28mm 2.8, on Konica Minolta Alpha Sweet
(aka, Dynax 5d). |
 |
< A Japanese
amusement park at dawn. F10, 1/2, iso100. Minolta 28mm 2.8, on Konica
Minolta Alpha Sweet (aka, Dynax 5d). |
 |
< More to come.
F__, 1/__, iso___. Minolta 28mm 2.8, on Konica Minolta Alpha Sweet (aka,
Dynax 5d). |
| |
We proudly support:
Get a guided tour of Angkor Wat
Home
Up
Learning English
Teaching English
Photography
Forums
Living in Asia
Community
Advertise with us
Contact Us
We support
|
