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Language Teaching in Japan
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A new lens: Minolta 100mm f2.8 Macro |
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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. This is a user review, that is, it's not an objective
review, but a subjective (user's) review. |
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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 50mm f1.4 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 100mm 2.8 macro
originally released in 1986, and
not the 100mm 2.8 or the 100mm soft. The difference being that the macro
is capable of macro / close-up photography, whereas the other two lenses
are great portrait and wedding lenses. These were 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 just under 150mm
using the APS-C sensor, perhaps making it too telescopic for portraits,
but better for insect photography
(see here for more
information on macros).
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| The
Minolta 100mm f2.8 macro |
For
more talk on these lenses |
First test shots (all handheld)
| Picture 1. A
close up of a very tiny frog that was sitting in the handle of a
fire hydrant hose box. Sony A200, f4, 1/125, iso100, with flash.
With APS-C the depth of field is shallower than on film or full
format sensors. Notice that even at f4 the nose and eyes aren't so
clear. This picture was quite heavily cropped. |
1.
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| Picture 2,
A Japanese beetle. Sony A200, f4.5, 1/125, 200iso, on-board flash
fired and was bounced onto a white fill card behind the beetle.
Because the lens is long and the hood adds length, and the lens was
really close to the subject, a lens hood could be used to shield the
beetle from direct flash. |
2.
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| Picture 3
These seed pods on a Japanese cedar were not too close. Though the
lens can be slow focusing, it can still do a great job. Sony A200,
f5, 1/320, iso100. |
3.
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| Picture 4
The bokeh in this appears wonderfully smooth.
At times I find that this lens tends to under expose a little. A few
adjustments in LightRoom 2.4 were necessary. However, it can perform
well in low, natural light. Sony A200, f5.6, 1/160, iso200. |
4.
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| Picture 5
A macro of a dragonfly on rice. Sony
A200, f4, 1/250, iso100. It seems to perform best when there is lots
of light available. |
5.
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| Picture 6
I used this lens extensively when making the
Minolta vs. Sony user
review page. It is perfect for getting these kinds of details.
Sony A200, f5.6, 1/125, iso100. |
6.
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| Picture 7
With macro lenses generally, you really need a
tripod and focusing rail to get the focus exactly right. Konica
Minolta 5d, f2.8, 1/80, iso100. |
7.
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| Picture 8
Here, only available light was used. Often a white card is needed to
help bounce light back into the shadows. Konica Minolta 5d, f4,
1/200, iso100 |
8.
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| Picture 9. |
9.
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| 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.
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12.
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13.
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| 11.
Aperture at f2.8, making this great for low light or high shutter
speeds. |
12.
Aperture at about half, showing the blades do not make a circle, but
an octagonal shape, so the bokeh will be only ok. |
13.
Aperture at f22. |
14.
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15.
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16.
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| 14. The
focus limiting switch is fantastic. This lens can be slow to focus,
and can easily go past the point that is should focus on. Using this
helps speed up the focusing process. |
15. The
lens at half focusing length. The front element does not rotate when
focusing, making it ideal for use with polarisers and gels. |
16. The
lens hood attached.
Due to the front element being so deep in the barrel (the barrel is
longer than the front glass) I very rarely need the hood. |
Comments
Similar lenses are available, such as the
Tamron 90mm macro, Sigma 105mm macro, Minolta 200mm macro, and the
Tamron 180mm macro. I've noticed the Canon professionals tend to prefer
the Tamron 180mm macro, whilst the Minolta 200mm macro is both ultra
expensive and supposedly the images it creates are apparently exquisite.
Some macro photographers, even in the Sony / Minolta camp would say that
they prefer the Tamron 90mm for [insert very good reasons here], and
others prefer the Sigma for [insert very good reasons], whilst the
Minolta 100mm macro would be counted as a close second to both. Not
having used the others, I can't say much, except that faster focusing
would be nicer. Now, having lived a bit more with it, I would have to
say that I'm itching to try the longer macro lenses, especially as I
find that the 100mm can be not long enough for my current interests.
Specifications:
Its minimum focusing distance is 35cm [1], and infinity is just beyond
the 3m range. This particular lens is of the 1986 release,
the first AF batch from Minolta, so it has 9 non-circular aperture blades [1]. Circular aperture blades makes for excellent bokeh,
a feature of later model top-level Minolta lenses. For more technical
information see references [1] and [2] below.
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 so well to a
digital sensor. The updated Sony lenses do have a coating which improves
colour transmission to the sensor. Also, this lens will work on full format sensors, with normal
100mm perspective. Though, on an APS-C sensor
(28mm sized frame), it has an equivalent of just under 150mm. 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 rather slow, and take a little time to hunt.
Money Talks:
Though the aperture blades are not circular, which is important to
create good bokeh, the bokeh quality is nonetheless exceptional for this
era (see sample pictures above). The Sony release of this lens is more
or less the same as the Minolta 2000 release which does feature circular
aperture blades [2]. However, the second hand price is substantially
less than a new Sony equivalent, but the quality will be almost the
same.
Flexibility:
Not much to report. It's not exceptionally large, outer body is made of
metal, so it will probably be durable, though a little heavy to carry.
Some say it can also be used as a portrait lens, though I would prefer
the plain 100mm 2.8 (non-macro) equivalent as a budget portrait lens,
which itself would be in-place of getting the 85mm 1.4 G.
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, but not a problem. The front screw mount is 55mm [1],
which is common in the Sony / Minolta range.
Quality Controls:
It's a great lens. It can be wonderfully sharp,
as seen in the sample pictures above. It being an f2.8 lens does allow for
great moderate-low light ability, as seen in pictures 2 and 4, above.
For a while, before I got the 50mm 1.4 and the 70-300mm G, this was
easily the best lens in my kit. Furthermore, I've never heard of any
mechanical problems with these.
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. Despite that apparently the Tamron 90mm macro
and Sigma 105mm macro is a nudge ahead of it, I still love it.
References
[1] Mhohner.de. Accessed 19 Sept 2009.
http://www.mhohner.de/sony-minolta/onelens/af100f28m
[2] Mhohner.de. Accessed 19 Sept 2009.
http://www.mhohner.de/sony-minolta/lenses.php
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