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Generally
speaking, the best performing optics are produced by the major
camera manufacturers while third-party manufacturers have always
assumed second place, or worse. Let's face it, few third-party
lenses can rival the best lenses produced by the major manufacturers
but, typically, a photographer will pay considerably less for
a third-party lens. Recently, Sigma has introduced third-party
lenses that come very, very close to the quality of OEM lenses.
Tamron,
on the other hand has produced a 90mm macro lens that rivals those
produced by the major manufacturers.
Price-wise,
a lens this well designed is not cheap to make and, as so, it
is priced within the same price range as those lenses offered
by Nikon and Canon. Retail prices for this lens run from US$459.00
to US$499.00. The latest iteration of the Tamron 90mm macro lens,
theTamron SP AF90mm f. 2.8 Di, has special coatings for use with
dSLRs but is optically the same as this lens.
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While
other manufacturers chose to make their macro lenses focus internally,
Tamron chose to make the 90mm macro lens using a more traditional
macro optical design that depends on external focusing. Canon
and Nikon internal macro lenses do not get longer when focused
closer but the focal lengths change as these lenses are focused
closer. The Canon 100mm macro lens, for example, changes focal
lengths from 100mm at infinity focus to a focal length of 78mm
when focused to 1:1 image magnification. Internal focus lenses
rely on internal extension and moving multiple lens elements to
achieve close focusing which necessitates a more complex optical
design.
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The
Tamron 90mm lens gets longer as you focus the lens closer. In
fact, the lens is becomes 50% longer when focused at 1:1 image
magnification than it is when focused at infinity. This results
in a simpler optical design with fewer lens elements and a much
lighter weight lens. The simpler the lens design the easier it
is to maintain corrections for chromatic and spherical aberrations
over a long focus range. The Canon 100mm f. 2.8 macro lens weighs
1.32 pounds and the Nikon 105mm f. 2.8 lens weighs 1.22 pounds.
The Tamron lens comes in under 1 pound at 14.5 ounces. Some photographers
are put off by the length of the lens at full 1:1 focus. At infinity
focus the Tamron lens is just a smidgen under 4" long. Extended
to 1:1 image magnification the Tamron lens measures nearly 6"
long.
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Some
photographers may be put-off by the change in overall length.
I, personally, do not find this to be an issue for my style of
photography. There is one disadvantage of an external focus lens,
however, that is valid concern. Because the lens elements in the
Tamron 90mm lens are extended away from the film/ccd/cmos plane,
the lens does lose approximately 2 f. stops of aperture at 1:1
image magnification. Internal focus macro lenses from Canon and
Nikon only lose 1 f. stop of light at 1:1 image magnification.
Again, I do not find this to be an issue with my photography but
it may bother some other photographers.
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Finally,
the front element of the Tamron lens is deeply recessed about
1.5". This makes for a very effective sun shade. Frankly,
the sun shade (lens hood) supplied with the lens is a huge abomination
that I recommend everyone to throw away. It is unnecessary to
use an additional sunshade unless you put filters on the front
of the lens. When I add filters to the front of the Tamron macro
lens I use an inexpensive rubber lens hood to protect against
flare. Not only does the deeply recessed front element protect
against flare but it also helps to keep the front element clean.
I am often "shooting in the dirt" and the recessed front
element is protected from dust and scratches.
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When
I was deciding which macro lens to buy to use on my Canon EOS
D30, I had the pleasure to borrow a Canon EF 100mm f. 2.8 macro
lens and the Tamron 90mm macro lens for a few days. If I had known
at that time that I would be writing a review of the Tamron macro
lens I would have saved the test images I made with the Canon
lens. Unfortunately, I have discarded these images. However, since
the Canon and Tamron lenses were both competitively priced at
that time I can say that I purchased the Tamron 90mm macro lens
based on its optical performance compared to the Canon 100mm macro
lens.
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Foremost
in my decision to buy the Tamron 90mm macro lens over the Canon
100mm was optical performance. The Tamron just edged-out the Canon
lens in both sharpness and contrast through the aperture range
from f. 11 to f. 22, my most used apertures. At f. 2.8 the Canon
lens was just barely sharper. From f. 4 to f. 8 the difference
between the 2 lenses was marginal. In this range the Tamron had
a slightly bit better contrast. At f. 32 both lenses exhibited
degraded sharpness and degraded contrast. After viewing raw images
I also felt the Tamron had a more neutral color reproduction than
the Canon lens but this is a highly subjective observation.
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the right are some test images I made of the label on the back of
a "Cream of Wheat" box. I like to use printed surfaces
as I can get a nice image of the dots that make up a lith printed
image. Click on the thumbnails to view the test images at a larger
scale. All of the test images were shot at 1:1 image magnification.
This is a macro lens and I use it as such. The vast majority of
my macro images are made at 1:1 image magnification or higher. All
of the test images are unsharpened as they come out of the camera.
The camera used for testing is a Canon EOS D30 dSLR. All images
were made on a tripod with the mirror locked up. No post-imaging
processing has been performed and the files have been saved as high-resolution
.jpegs.
The Tamron
90mm macro lens does make a fine portrait lens but, be forewarned,
it will record every minute detail of a face. A little "skin
smoothing" may be required in Photoshop to produce flawless
and less harsh skin details.
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Click
on an f. stop, above, to review the test results.
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The
Tamron 90mm macro lens may be used quite success-fully with any
good quality teleconverter to increase image magnification or
to increase working distance. In fact, I prefer to add a 2x teleconverter
(Kenko MC-7 2x teleconverter) to the Tamron 90mm lens rather than
purchase and carry a larger, heavier 180mm macro lens. I give
up only one f. stop of maximum aperture compared to a 180mm macro
lens and I still have a highly portable, handholdable macro lens.
To the right is an image made with the 2x teleconverter attached
to the Tamron lens. Very little sharpness is lost using a teleconverter
on the Tamron lens. I do have a 1.4x teleconverter I will sometimes
use but I seldom use it on the lens alone. Most of the time, when
I want more image magnifi-cation, I want a lot of image magnification.
Under these circumstances I will stack the 1.4x teleconverter
on the 2x teleconverter for a 3x increase in image magnification.
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Click on image, above, for a larger view. |
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The
Tamron 90mm macro lens forms the basis of my general macrophotography
kit. To the lens I will add Nikon 3T and 4T supplementary lenses,
the aforementioned teleconverters, and various combinations of
Kenko extension tubes to achieve the image magnifications I desire.
Regardless of the combinations of accessories I add to the lens
the resulting images are very sharp with good contrast and have
very accurate, natural colors. One issue I would like to note,
however, is that it is very difficult to mount a reversed 50mm
lens to the Tamron 90mm macro lens. The front element of the Tamron
macro lens is so deeply recessed that it is impossible to avoid
vignetting in the image without adding at least 36mm of extension
between the lens and the camera body. I am not too concerned about
this as I do not often use this technique to gain image magnification.
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Click on the image, above, for a larger view. |
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| Would
I recommend the Tamron SP AF90mm f. 2.8 macro lens to other macrophotographers?
This would be a big, emphatic...YES!! |
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Disclaimer:
These
are only my opinions and must not be confused with product
evaluations written from carefully controlled tests. My reviews
are "real world" reviews based on my experiences using
these specific pieces of equipment utilized for my type photography
and the manner in which I work. Other photographers may offer
differing and valid opinions of the same equipment.
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Copyright
Thomas L Webster, 2005. All rights Reserved.
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