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Canon EF 24-105
4L IS USM Review
Lensman
Nirvana?
Peter
Kun Frary
Normal
Lenses and Zooms
The 46 degree coverage
of the 50 mm lens is equivalent to the sweet spot of the human
eye. Hence, "normal lens," is
the term used to describe this focal range. What is a normal
zoom lens? It's a zoom that "dances" around both
sides of the old 50 mm standard. Thus, 24-70, 24-85, 24-105,
28-70, 28-80,
28-105, 35-70, 35-105, 35-135, etc., are considered normal zooms.
It's also the most useful range for general 35mm photography,
encompassing wide, normal and short telephoto ranges. Mount
a normal zoom
on your SLR and you're good to go for scenics, group
shots, candids and portraits. For many weekend and holiday
shooters this is the only lens they need.
Propeller,
Pole & Palm • EOS
5D, EF 24-105 4L IS USM

EF 24-105 4L
IS USM, Not So Normal
"Normal Zoom"
Introduced late 2005, the EF 24-105
4L IS USM is
an astonishing feat of engineering with Image Stabilization, constant
aperture,
wide zoom range (4.4x), beefy construction and weather seals. I
bit the bullet and replaced my
oft
and long used travel companion, the
EF 28-135 3.5-5.6 IS USM, with
this amazing optic.
Canon
EF 24-105 4L
IS USM

Build
Like A
Brick
For
a normal zoom, it's large and beefy,
670 g (23.6 oz), but much lighter than
its cousin the EF 24-70 2.8L USM. Build quality is first
rate but
sports more
plastics than L series telephotos. The
black finish is more stealthy than the attention grabbing white
of
Canon's super telephotos.
According
to Canon's Chuck Westfall,
"this lens
has the same degree of sealing as the EF24-70mm L lens. Both
are weather sealed with gaskets at the
lens mount, under the switches, and behind the zoom and focus
rings." The manual states that a filter
must be used to achieve full weather proofing.
MGM Grand,
Las Vegas • EOS
5D, EF 24-105 4L IS USM • 1/13 sec, F4, ISO 800, -1
EC, IS engaged

Focus and Zoom
A ring-type
USM (Ultrasonic Motor) achieves focus by driving an
internal lens
group.
Needless to say, AF is extremely fast
and surefooted on my EOS 5D and 3 bodies. The front element
does not rotate and the
barrel does not expand or
contract
during
focusing.
Of course, being an USM lens, it is silent during AF.
It has FTM, allowing you to manually focus without switching out
of
AF mode. The focus ring is large, smooth turning
and covered with ribbed rubber.
It's not as silky as a manual Nikkor but above average for
an AF lens. If
you prefocus manually, the distance window in meters and feet is
extremely useful. Although not a macro
lens, it focuses close enough for head shots and small details
(.45 m/1.5 ft).
The
twist zoom action is smooth, damped and does not creep. Zooming
is accomplished by expanding and contracting
a single nested barrel. The barrel extends considerably--nearly
doubling in length--while zooming to 105
mm. The
manual focus ring is large and covered with a ribbed rubber surface.
The 77 mm
filter size makes for expensive filters, but at least I can
share filters with my EF 17-40 4L USM. The
manual recommends removing the hood while
using
a polarizing filter. However,
if you have agile fingers
it's easy to rotate the filter through
the petal cutouts of the lens hood.
Agashi
at the Venetian EOS
5D, EF 24-105 4L IS USM & 430EX
Speedlite. I shot wide open at F4 in
Av mode, allowing the 430EX Speedlite to render auto fill-in
flash, blending subject and background light. Amazingly,
no flash compensation was needed. The flash head was manually
zoomed to limit coverage to subject only (didn't want to
illuminate the fence).

Optical Quality
This
is the best zoom I have used.
It is sharp and contrasty wide open at
all focal lengths.
Oddly, sharpness doesn't improve much when
stopped down. However, it
is sharper than my EF 50 1.4 USM
at 50mm F4.
It's sharper than my EF 70-200 4L USM at 105mm F4.
The contrast and snap of this lens
is apparent even through the viewfinder. After all, there's some
pretty exotic glass in there, e.g., one Super-UD glass element
and three aspherical elements. Amazingly,
there are 18 elements in that little barrel. I'm
surprised light makes it to the other side!
The
short end, like all wide
zooms, suffers from noticeable barrel
distortion. The long end has a small
amount of pincushion distortion. Neverthelss,
distortion is less
pronounced than my EF 28-135 3.5-5.6 IS USM and EF 24-85 3.5-4.5
USM. For
most types of images, distortion
isn't readily apparent. However,
architectural and product photographers may
want to stick
with primes.
Flare
is well controlled for a zoom and
far less apparent than the EF
28-135 3.5-5.6 IS USM and EF-S 17-55 2.8 IS USM, so
shooting sunsets is a possibility with this optic. Notice
how clean this sunset picture is. In
contrast, the
EF
28-135 3.5-5.6 IS USM suffers
from severe ghosting,
something I haven't seen with the EF 24-105
4L IS USM.
Lens
For Ebay • EOS
5D, EF 24-105 4L IS USM, Bogan Tripod & White Reflectors.
The 1.5 foot minimum focus is useful for product photography
in a pinch.

Like
all wide zooms, the EF
24-105 4L IS USM suffers from light fall-off
at the wide end when shot wide open. Stop
down to F5.6 and light fall-off is reduced considerably.
By F8 it is nominal. Although wide primes and zooms suffered
light fall-off in the film era, most folks didn't notice
because labs cropped their prints. Even slide mounts covered
10% of the frame. Now people--especially
5D owners--whine about
light fall-off because they pixel peep and rarely print. However,
standard print sizes, e.g., 8 x 10 or 11 x 14, are cropped,
so most light fall-off will be nixed.
I
use wide angle for sweeping vistas and
stop down for maximum depth of field, so light fall-off
hasn't reared its head, except, of course,
in test shots of white walls. Basically light fall-off will only
be a problem if you shoot bright skies or white walls wide open
at 24mm
F4.
If
you shoot with a APS-C body, e.g., Rebel XT, 20D or 30D,
light fall-off is a moot point as 40% of the image circle is
cropped
out.
Image Stabilization
This would be a kickass lens
without Image Stabilization (IS). However, IS propels
this zoom into a higher universe of performance.
Small gyro sensors coupled to a CPU detect the degree and direction
of camera shake and counteract
this vibration by moving a compensating optical group. Subsequently,
I almost always get a sharp picture, even three stops
below
my normal hand held shutter speed. If I brace myself or shoot
a volley of shots I can get away with another
stop or two!
Ballys at Las
Vegas • EOS
5D and EF 24-105 4L IS USM hand held.
ISO 800, 1/60 second at F4 with IS engaged. Difficult to see the
light fall-off isn't it? Check the lower right.

IS has changed the
way I take pictures. I used to put away my camera when conditions
got dark, now I keep
on shooting (I avoid
flash except for fill). However, IS is not just for dim conditions,
it helps eminently in any high vibration situation such
as high wind, airplanes, automobiles or boats.
Image Stabilization does
nothing for subject
movement and will not replace a large aperture prime for sports
shooters. However, IS is a Godsend for general photography
and worth its weight in gold.
Currently
this is my fav walkaround and
the ultimate ready-for-anything travel lens. IS
coupled with the clean high ISO of the 5D leave few
excuses for missing a shot.
Conclusion
This is
the big Kahuna of normal zooms. It's exceedingly
well made and sharp as a tack. It swept me off my feet and displaced my oft
and long used companion, the EF 28-135 3.5-5.6 IS USM.
I love the range,
AF speed, sharpness and feel of this lens. It balances perfectly
on larger bodies such as the EOS
3 or 5D but is extremely
front heavy on smaller cameras such
as Rebels and Elans.
Finally, I have heard
reports of some copies being less than stellar in terms of
sharpness, so be sure to
run test shots on a tripod when you get it.
Highly recommended serious amateurs,
doctors, lawyers and world trekkers.
Not recommended
for those wishing to
travel light, sports photographers or those with a feeble credit
card limit.
More Images
taken with the EF 24-105 4L IS USM (click
to enlarge)
Source Materials
Canon EF Lens
EF24-105mm F4L IS USM Instruction
Manual. Tokyo:
Canon, 2005 (CT1-7561-001).
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6/1/2006 • Updated
7/4/2006
©Copyright 2006
by Peter Kun Frary All Rights Reserved