Tamron SP AF200-500MM F/5-6.3
Di LD (IF) Review
by Bob Atkins; created 2004
The Tamron SP AF200-500MM F/5-6.3 Di LD (IF) is one of Tamron's new "Di"
lenses. These are lenses designed with digital SLRs in mind. This is what Tamron
says about their DI lenses:
Di: Digitally Integrated Design, is a designation Tamron puts on
lenses featuring optical systems designed to meet the performance characteristics
of Digital SLR cameras.
Tamron's new Di (Digitally Integrated design) lens series offers users of both
film and digital cameras:
- Higher resolution
- Control of flare and ghosting
- Minimized peripheral light fall-off
- Reduced chromatic aberrations
Of course it's hard to say if, or how much, "digital" lenses are better than
"non-digital" lenses since there are rarely (if ever) digital and non-digital
versions of the same lens. While it's true that there are some aspects of lens
design that could be optimized for digital use, it's hard to say just how much
better a new "digital" design would be when compared to a new "non-digital"
design. There are many lenses designed before digital SLRs became popular which
seem to work perfectly well on digital SLRs. On the other hand lens design has
always been an evolving art and science, and improved designs may give improved
performance with both digital sensors and film. It certainly never hurts for
either to improve resolution, lower chromatic aberration, minimize light fall-off
and lower flare and ghosting!
Here are the specifications of the Tamron SP AF200-500MM
F/5-6.3 Di LD (IF)
|
Tamron SP AF200-500MM F/5-6.3 Di LD (IF)
Specifications
|
| Model Number |
A08 |
| Lens Construction (Groups/Elements) |
10/13 (2 LD elements) |
| Angle of View |
12°-5° |
| Focal Length |
200mm to 500mm |
| Maximum Aperture |
f5 to f6.3 |
| Diaphragm Blade Number |
9 |
| Minimum Aperture |
f/32 |
| Minimum Focus |
2.5m (98.4") (entire zoom range) |
| Macro Mag. Ratio |
1:5.0 (at 500mm) |
| Filter Diameter |
86mm |
| Weight |
1237g (43.6oz) |
| Diameter x Length |
3.7 x 8.9in. (200mm setting, no hood)
(93.5 x 227.0mm) |
| Accessories |
Lens hood, Detachable Filter Effect Control, Carrying case
and strap |
| Mount |
Canon, Minolta-D, Nikon-D |
The lens appears to be well constructed and has a low reflectivity black
finish with a rubberized zoom control. It comes with the following
accessories:
- Plastic "bayonet" mount lens hood with ribbed interior to minimize
reflections.
- Detachable tripod mount
- Soft zippered carrying case with detachable strap
- Detachable filter effect control
- Front and rear caps, instruction sheet, 6 year warranty
The carrying case is actually useful, unlike either the thin unpadded bags or
cylindrical hard cases supplied with some lenses. It's well padded and has a
detachable carrying strap. If I owned this lens I think I'd use this case often.
I have cases supplied with some lenses I've bought which have sat on the shelf
gathering dust since the day I bought the lens!
The Filter Effect Control is an interesting idea. One of the problems of using
a polarizer with telephoto lenses is that when you mount the long lens hood you
can't easily get to the polarizer to adjust the polarizing angle. The rotating
filter effect control is a detachable adapter that allows a polarizing filter to
be rotated by rotating the whole lens hood. The filter screws into the adapter
and the adapter screws into the lens. The hood then bayonet mounts onto the front
of the adapter which is free to rotate.
The metal tripod mount is easily detachable, yet hold the lens solidly when in
place and locked. There are no "clickstops" for horizontal and vertical
alignment, though there is an indicator mark for horizontal orrientation. It
tightens and loosens by rotating a small knob on the left side of the lens.
The zoom can be locked in the 200mm position so that the lens doesn't extend
when being carried in a downwards position. The lock is only possible at 200mm.
Focal lengths are marked at 200mm, 250mm, 300mm, 350mm, 400mm, 450mm and
500mm.
Focus can be switched between AF and MF with a small switch on the left, near
the lens mount. Manual focus is smooth, if a little fast for delicate adjustments
with about a 57 degree rotation from 2.5m to infinity. There is no depth of field
scale, and this is no surprise since DOF scales are pretty useless on telephoto
lenses and very difficult to design for zooms. There is no IR focus
identification mark.
The image below show how the lens extends on zooming. At 200mm, without the
hood, it's similar in size to an 80-200/2.8 zoom or a 300/4 prime. Add the hood
and it becomes quite a bit longer and zoom to 500mm and it becomes an impressive
sight! For scale, the camera attached to the lens in these shots is an EOS 10D.
Note the filter effect control adapter is mounted between the lens and the hood
in these images.
The lens takes an 86mm screw-in filter. 86mm filters aren't cheap and you're
unlikely to already own many since few 35mm camera lenses require such a large
filter. For example an 86mm circular polarizer (which is probably the most
commonly used filter) will cost you somewhere between $100 and $225 depending on
the manufacturer. Currently the Tiffen sells for around $120 and the Hoya sells
for around $145. Something to budget for if you're addicted to polarizers.
The lens does not change length on focusing (it's internal focus - IF) and the
front of the barrel does not rotate when the lens is zoomed or focused. However
the focus ring does spin during autofocus, so keep your hands away from it!
The lens has a close focus distance of 2.5m (98.4") at all focal lengths.
Maximum magnification is 1:5 (at 500mm).
Performance Tests
Autofocus
Autofocus on an EOS 10D was positive with no "hunting" observed at any focal
length under a variety of daylight conditions from full mid-day sun to evening
shade. Though not silent, AF noise was low and certainly acceptable. I measured
the time taken to shift focus from 2.5m to infinity (or infinity to 2.5m) at 1.1
seconds. By way of comparison, the Canon EF 300/4L USM takes 0.65 seconds to
focus from 2.5m to infinity, the Canon EF 75-300/4-5.6 IS USM takes 0.9 seconds
to focus from 1.5m to infinity and the Canon EF 500/4.5L takes 1 second to focus
from 4m to infinity. So while 1.1 seconds isn't as fast as some Canon USM lenses,
it not that much slower. All these times were measured with the lenses
mounted on a Canon EOS 10D body.
Focal Length and Aperture
The nominal focal length and aperture is 200mm f5, to 500mm f6.3. I recorded
the following EXIF data recorded when the lens was mounted on an EOS 10D and
zoomed to 500mm
The blue data is the recorded shooting data which says 500mm, but
the green data which is the lens identifier indicates a minimum focal length of
200mm and a maximum focal length of 486mm. When I compared shots taken with a
Canon EF 500/4.5L with those taken with the Tamron zoom at full extension (500mm)
I measured objects in the Tamron images to be about 3% smaller than those in the
Canon images. I've previously tested the Canon lens and found it to be very close
to 500mm in focal length, so using that as a reference the calculated Tamron
focal length would be 485mm. This is very close to the EXIF value of 486mm, so I
tend to believe that it probably does represent the actual maximum focal length.
Note that it's still well within the usual +/- 5% standard for focal length
measurement which is widely adopted (475mm to 525mm for a 500mm lens). If you
look back though Popular Photography lens tests you'll see that lenses
are rarely exactly as marked and that most telephotos are up to 5% shorter than
their nominal focal length.
When mounted on an EOS 10D or 20D the indicated aperture at 200mm
was f5, from 290mm to 450mm it was f5.6 (1/3 stop slower) and from 450mm to 500mm
it was f6.3.
Image Quality
Here comes the part you've been waiting for! Just how good is
this lens? Well, I performed a variety of tests, shooting both "regular" images
and comparing them to other lenses (Canon EF 75-300/4-5.6 IS USM, Canon EF 300/4L
USM and Canon EF 500/4.5L ISM), as well as shooting images of test targets and
doing scientific (or at least semi-scientific) quantitative analysis of the
results. I've been playing around with a lens/camera/printer testing software
suite called
Imatest,
written by Norman Koren. I'm not going to present hard data in this review since
I haven't used the software enough yet to fully evaluate it and get experience
with interpreting the results. However at some point in the future I may
incorporate such test data in reviews.
All testing was done using an EOS 10D DSLR with an APS-C sized
sensor (approx 15.1 x 22.7mm).
Tests for vignetting showed none at any focal length or aperture.
Illumination was very uniform across the frame. Of course this would be expected
since the lens is designed with full frame 35mm coverage and was tested on a
camera with an APS-C sensor which crops the center 15x22mm region from the 43mm
image circle. Vignetting on a full frame camera was not tested. It's not unusual
to see some degree of vignetting in the corners of a full 35mm frame with
any lens when used wide open.
The above sequence shows the effect of zooming from 200mm to
500mm. Of course you can't really tell much about image quality from such small
images, so the following sequence of images show 100% crops from the center of
each image.
Here are some comparison images shot with Canon lenses as
indicated.
You'll probably see that there's not a whole lot of difference
between any of the lenses! This is due to several factors. First the subject is
low contrast and doesn't have a lot of fine detail. Second the images are all
shot with an EOS 10D, which has a resolution limit of 65 lp/mm. Third all these
crops are from the very center of the image, where aberrations in all lenses are
at a minimum. There are differences, but they are small in this particular image
sequence.
So does that mean that the Tamron 200-500 is just as good as a
Canon EF 300/4L or Canon EF500/4.5L? Well, not really as you can see from the
following images. These are shots of a white bar against a dark background at the
edge of an image. First a sequence shot at 300mm and f11. Note that chromatic
aberration isn't a function of aperture, so the color fringing will be
essentially the same wide open and stopped down. These are 200% enlargements of a
crop from the test images.
As you can see, the Tamron 200-500 at 300mm falls somewhere
between the Canon EF 75-300 IS and the Canon EF 300/4L. The use of LD (low
dispersion) elements in the lens is clearly suppressing some of the chromatic
aberration, though not quite as effectively as the UD elements of the Canon
prime. Below are the results at 500mm. These are also 200% enlargements of a crop
from the test images.
Clearly the Tamron 200-500 at 500mm is showing some edge
chromatic aberration. The Canon EF 500/4.5L is extremely clean with no visible
color fringing at all. Obviously the use of fluorite and UD elements in this lens
is highly effective at eliminating chromatic aberration. However the Canon lens
costs around $5000, so you pay dearly for the improvement. Comparing an $875 lens
with a $5000 is, of course, not really fair, however a good reason to do this
comparison with the much more expensive lens is to show that chromatic aberration
is not being caused by the digital sensor in the camera. It has been suggested in
some publications that color fringing can be caused by sensor aberrations.
Whether or not this is ever true, it appears not the case in these tests.
Here's a shot of a high contrast test target with lots of fine
detail. All the images were shot at 500mm and f6.3, this time taking crops from
the center of the image and a point 40% of the distance to the edge.:
This time, even in the center of the image, the Tamron 200-500
shows lower contrast (lower MTF) than the Canon lens (again though, remember
you're paying around $5000 for the Canon lens!). Note however that the resolution
in the top images (taken from the center of the frame) is very similar. Both are
probably limited by the resolution of the sensor in the 10D.
At 40% of the distance from the center, the Tamron lens has lost
some sharpness and is starting to show some chromatic aberration. This is
probably less of a problem in telephoto lens than in a wideangle lens, since
telephoto lenses are usually used with the subject in the central region of the
frame and limited DOF tends to render the background out of focus.
Here's another image set shot at 500mm. The upper image is the
full frame shot and the lower image is a 100% crop. Again, comparision with a
$5000 prime lens isn't "fair", but it does give a reference standard. The
performance of the Tamron 200-500 is certainly acceptable for a 200-500 zoom
costing under $1000. Remember that the 100% crop represents what a very large
print would look like. The crop is 268 pixels wide, so the full image, if
displayed at the same scale, would be 11.5x larger. On my monitor (17" screen,
1280 pixels wide), this would mean a full frame display which was 20"
x30".
Below are the same crops, but this time at 50% and with a little
unsharp mask sharpening. It's now starting to get harder to see the
difference!
I also compared the Tamron SP AF200-500MM F/5-6.3 Di LD (IF) to
the Tamron SP 500/8 mirror lens. The 200-500 at 500mm was slightly sharper in the
center of the image than the mirror lens, but showed more chromatic aberration at
the edges of the frame. Of course the mirror lens is a stop slower, manual focus,
isn't a zoom and has donut shaped out of focus highlights (poor "bokeh"). On the
whole, the Tamron SP AF200-500MM F/5-6.3 Di LD (IF) is a much better choice for
most users.
Earlier in this review I mentioned that I'd been using the
Imatest program to obtain quantitative data on image quality. Actually I measured
something called the system response function which is a measure of overall image
quality (or system MTF if you prefer). These quantitative results ageed well with
the purely visual estimates of image quality, both in terms of image sharpness
and chromatic aberration. They also show that the Tamron 200-500 does sharpen up
a little when stopped down and this applies at all focal lengths. The difference
isn't huge, but stopping down to f8 when convenient will give slightly sharer
images. At 500mm stopping down to f11 gives a little more sharpness still.
Multipliers
You might think it would be asking for trouble to use a multipler
on a 200-500mm zoom, and often you'd be right. Multipliers work best on high
quality (read "very expensive") prime lenses, but since I had a few multipliers
around I thought it would be interesting to test them with the zoom. I found that
the Canon EF 1.4x TC would fit the Tamron 200-500 as long as the lens was zoomed
out. At 200mm the rear element of the zoom comes into contact with the front
element of the TC. I also used a Tamron 1.4x TC, though possibly not the current
version since I bought it about 10 years ago. The designation on this multiplier
is "Tamron-F AF tele-converter 1.4x C-AF MC4".
My first surprise was that the Tamron TC outperformed the Canon
TC, even though it cost about $200 less. I repeated the tests and got the same
results. The images taken with the Tamron TC were sharper. Neither TC gave very
good AF. With the Tamron AF was possible and focus lock was obtained on some
subjects, but it wasn't reliable. With the Canon TC there was a tendancy to
oscillate about a focus point. Of course you wouldn't expect AF. Canon AF is
specified to work only at f5.6 or faster. With a 1.4x TC on the Tamron lens at
500mm the effective aperture is f9. Manual focus was fine, but as I commented
earlier, with a 57 degree rotation from 2.5m to infinity, small focus adjustments
were tricky - but possible.
Let me apologize in advance for the artistic quality of the test
image below, but my "model" wasn't being very cooperative on the day of the test
and insisted on hiding in the bushes! The upper image is the full frame shot,
taken with the Tamron 200-500 lens at 500mm with the Tamron 1.4x TC added. Manual
focus of course, and a focal length of 800mm at f9 (equivalent to 1280 mm on a
full frame 35mm body).
Below is a 100% crop from the center of this image. This is only
456 pixels wide, so the full image would be 6.7 times wider. As you can see
quality isn't awful. It's decent considering the circumstances and, in fact,
better than I would have expected.. You can see the eyelashes on the deer! I'd
estimate the deer was at a distance of about 50m (165ft). Again, with the 1.4x
TC, remember that this is equivalent to using a 1280mm lens on a full frame 35mm
camera
What about use on a full frame film or DSLR?
Well, the general conclusions will still apply. The center of the
image will be the same, but the edges will be a little softer on a full frame
camera and the extent of chromatic aberration will be a little greater.
Conclusions
The Tamron SP AF200-500MM F/5-6.3 Di LD (IF) is a pretty decent
telephoto zoom for the price (around $875 discount). It's well made, feels
sturdy, the tripod mount is stable and focus is accurate. The hood is deep and
effective and the supplied filter effect control adapter is a neat idea. The
supplied soft case is useful and protects the lens well. The 6 year warranty is
also a plus. Most lenses only come with a 12 month warranty.
Optically the lens isn't a match for a prime apochromatic
telephoto lens, but that's not a fair comparison. It's less than 1/5th the price
of a 500mm f4 lens and less than a third of the size and weight, plus it zooms
from 200-500mm. Zoom lenses are usually a compromise, particularly long telephoto
zooms and for most users the compromises are quite acceptable. You get somewhat
lower, but still accetable, image quality, but a much lower price and a lot more
convenience. The "street" price on the Tamron SP AF200-500MM F/5-6.3 Di LD (IF)
is around $875 from reputable discount retailers.
I could certainly recommend that those who want a fairly
inexpensive telephoto zoom should look at this lens. If you're intending to make
your living by selling poster size fine art prints of your work you probably need
a more expensive prime lens, but if you're shooting for fun and not intending to
make huge prints, the Tamron SP AF200-500MM F/5-6.3 Di LD (IF) is certainly a
lens worth considering..
Where to Buy?
The following retailers are photo.net affiliates. Please consider
purchasing from them if you're interested in this lens. Doing so will help
support this website.
| Canon EOS Mount |
Nikon Mount |
© Copyright 2004
Bob Atkins (www.bobatkins.com)
Add a comment