Sigma 18-35mm F1.8 DC HSM Review

Transcription

Source: http://www.dpreview.com/lensreviews/sigma-18-35-1-8
QUICK LINKS:
News
Reviews
Buying Guide
Sample Images
Videos
Articles
Sample Images
Cameras
Camera Timeline
Lenses
Phones
Link Directory
Printers
Software
Forums
Galleries
Challenges
Search on dpreview.com
1. Introduction
Sigma 18-35mm F1.8 DC HSM Review
September 2013 | By Andy Westlake and Richard Butler
Like
588
Tweet
49
10
Log in to dpreview
Not a member? Register
Pages
Review based on a production Sigma 18-35mm F1.8 DC HSM
Sigma has a long history as a lens maker, having been founded over 50 years ago. In the film era it was best
known for relatively inexpensive lenses that undercut the camera makers' own equivalents in terms of price.
But this has changed over the part decade or so; while other companies have shifted manufacturing to
cheaper locations such as China and Thailand, Sigma has stubbornly refused to move from its factory in
Aizu, Japan. This means it can no longer compete in the same way on price alone, and it's therefore
switched its focus towards higher-value offerings.
Introduction
Design and...
Test results
Test results
Overall...
Conclusion...
Over the past few years we've seen increasingly ambitious concepts appear from the company's design
studios. The original (and recently-replaced) 30mm F1.4 EX DC HSM has long been one of our favourite
lenses for APS-C SLRs, and the 50mm F1.4 EX DG HSM grabbed our attention back in 2008 due to its
sharpness at large apertures. Most recently the 35mm F1.4 DG HSM impressed us with its exceptional optical
quality at a very competitive price. This all bodes well for the company's latest offering - the record-breaking
18-35mm F1.8 DC HSM, which is the first constant F1.8 SLR zoom lens to hit the market.
Sigma's choice of F1.8 as maximum aperture isn't a coincidence; it means that the lens will offer the same
control over depth of field as an F2.8 zoom does on full frame. What's more, it will also offer effectively the
same light-gathering capability as an F2.8 lens on full frame. By this we mean that it will be able to project
an image that's just over twice as bright onto a sensor that's slightly less than half the area, meaning the
same total amount of light is used to capture the image. This is important as it's a major determinant of
image quality. Essentially it means that APS-C shooters will be able to use lower ISOs when shooting wide
open in low light and get similar levels of image noise, substantially negating one of the key advantages of
switching to full frame.
As we'd expect at this level, the lens uses an ultrasonic autofocus motor for fast, silent focusing. It's
compatible with Sigma's new USB dock which allows you to fine-tune autofocus behaviour in much more
detail than the AF microadjust corrections found on SLRs, which should help get the best possible focus
accuracy and make the most of the large aperture. It also incorporates several of the thoughtful design
touches that we were impressed by on the 35mm F1.4, including an improved AF switch, and a large grip
area on the base of the barrel for better handling.
The lens's 27-53mm equivalent focal length range is obviously a little limited, but should still be rather useful
for such applications as wedding and events photography. So while it may not quite match the capabilities
of a 24-70mm F2.8 on a full frame SLR, for existing APS-C users it should offer something very close.
Crucially, at a street price of around $800 / £650 at the time of writing, for existing APS-C shooters it's an
awful lot cheaper than buying a 24-70mm F2.8 and a full frame SLR to go with it.
Preview...
Latest reviews
Sigma 18-35mm F1.8 DC HSM
Sep 2, 2013
86%
Overall the 18-35mm F1.8 is a really intriguing product, and we applaud Sigma for pushing the boundaries
of lens design ahead of the more conservative camera manufacturers. But can an F1.8 zoom really deliver
good results? Let's find out.
Sony Alpha A3000
Headline features
PREVIEW
Aug 26, 2013
18-35mm focal length (approx 28-50mm equivalent)
Extremely fast F1.8 maximum aperture
Ring-type ultrasonic focus motor with full-time manual override
Initially available in Canon EF, Nikon F and Sigma SA mounts; Pentax K and Sony Alpha to follow
Angle of view
Canon EOS 70D
The pictures below illustrate the focal length range from wide to telephoto (on Canon APS-C, 1.6x). The 1835mm covers a modest 2x zoom range.
Aug 15, 2013
PREVIEW
Sigma USB Dock quick review
Aug 12, 2013
2013 Waterproof Group Test
Aug 9, 2013
18mm (29mm equivalent)
35mm (56mm equivalent)
Pentax Q7
Aug 8, 2013
Sigma 18-35mm F1.8 DC HSM specifications
70%
Date introduced
April 2013
Street Price (August 2013)
• $800 (US)
• £650 (UK)
• €850 (EU)
Maximum format size
APS-C
Focal length
18-35mm
35mm equivalent focal length (APS-C)
• 27-53mm (1.5x)
• 29-56mm (Canon 1.6x)
Sigma 17-70mm F2.8-4 DC
MACRO OS HSM | C
Aug 5, 2013
Diagonal angle of view
76.5° - 44.2°
Maximum aperture
F1.8
Minimum aperture
F16
Lens Construction
• 17 elements in 12 groups
• 5 SLD glass elements
• 4 glassmold aspherical elements
Number of diaphragm blades
9, rounded
Minimum focus
0.28m / 0.92ft
80%
See more...
Latest news
Maximum magnification
0.23x
AF motor type
• Ring-type Ultrasonic Motor
• Full time manual focus
Focus method
Internal
Zoom method
Rotary, internal
Image stabilization
No
Filter thread
• 72mm
• Does not rotate on focus
Supplied accessories*
• Front and rear caps
• Lens hood LH780-03
Weight
810g (28.6 oz)
Dimensions
78mm diameter x 121mm length
(3.1 x 4.8 in)
Lens Mount
Canon EF, Nikon F, Pentax K, Sigma SA, Sony A
This week
DxO Optics Pro 8.3.1 adds support for five recent
cameras
Olympus fraud saga rumbles on with UK
prosecution
Microsoft to acquire Nokia's smartphone business
DxOMark tests Canon EOS 70D sensor and lenses
Back to the future: ten one-of-a-kind cameras
from the 21st century
Need the speed? Sigma 18-35mm F1.8 DC HSM
in-depth review
Ilford opens US lab to meet demand for black
and white film development
Goldfish all gone? Turn that empty tank into an
underwater housing
Black-and-white images capture the power of
summer storms
Last week
Billboards offer tourists a glimpse of smog-free
Hong Kong
* Supplied accessories may differ in each country or area
If you're new to digital photography you may wish to read the Digital Photography Glossary before diving
into this article (it may help you understand some of the terms used).
This article is Copyright 2013 and may NOT in part or in whole be reproduced in any electronic or printed
medium without prior permission from the author.
1. Introduction
Editorial content
Camera reviews
Lens reviews
Printer reviews
Previews
Sample images
Articles
Glossary
Product database
Cameras
Lenses
Printers
Software
Smartphones
Camera search
Camera comparison
Community
Forums
Challenges
Galleries
Polls
My Profile
My Settings
My GearList
Connect with dpreview
Subscribe to the weekly newsletter
QUICK LINKS:
News
Reviews
Buying Guide
Sample Images
Videos
Articles
Sample Images
Cameras
Camera Timeline
Lenses
Phones
Link Directory
Printers
Software
Forums
Galleries
Challenges
2. Design and Operation
Design
Log in to dpreview
The 18-35mm follows in the same design idiom as Sigma's most recent lenses such as the 35mm F1.4 DG
HSM. The section of the barrel between the mount and the zoom ring is metal, and the central section is
composed of Sigma's 'Thermally Stable Composite' in an attempt to balance strength and weight. Rubber
grips on the focus and zoom rings, combined with a high level of fit and finish, bring a sense of quality to
proceedings. As always, on Sigma lenses, the mount itself is plated brass.
In terms of design and control layout the lens is decidedly conventional, with a large manual focus ring at
the front, a zoom ring placed closer to the camera body, and a distance scale and focus mode switch placed
between the two. As usual for this class focusing is internal; less conventionally for a normal zoom, so is
zooming, which means that the lens stays the same length at all times.
Pages
On the camera
There's no denying that the 18-35mm is a pretty large lens - it's 10mm longer than the Tamron 24-70mm
F2.8. It's also a fairly heavy lens - essentially the same weight as the more rangey Tamron. However it
balances pretty well on high-end SLRs such the Canon EOS 7D shown left, helped by the camera's
substantial hand grip. We suspect it's likely to be found on this class of camera most of the time.
On smaller, lighter entry-level SLRs such as the Canon EOS 650D, the overall balance becomes more front-
Introduction
Design and...
Test results
Test results
Overall...
Conclusion...
heavy, meaning you'll often find yourself supporting the camera by cradling the lens itself. Frankly, these
models tend not to have hand-grips that are comfortable to hold for long periods anyway, so this
encouragement to support the lens is no bad thing.
Size compared
Preview...
For a better idea of its size, here's the 18-35mm lined up alongside Sigma's 17-50mm F2.8 EX DC OS HSM
and the recent Tamron SP 24-70mm F/2.8 Di VC USD. It's the narrowest in diameter but longest of the
three, and weights almost as much as the full-frame Tamron.
Against the slower Sigma, the 18-35mm is considerably longer, and weighs 40% more. However, its more
substantial build makes it more akin to the aged Nikon AF-S DX Nikkor 17-55mm f/2.8G, compared to which
it's only 1cm / 0.4" longer, and 7% heavier.
Latest reviews
Sep 2, 2013
86%
Sony Alpha A3000
PREVIEW
Aug 26, 2013
Canon EOS 70D
PREVIEW
Comparing the 18-35mm on a mid-range APS-C body to the Tamron 24-70mm F2.8 on one of the latest,
similarly enthusiast-focused full frame DSLRs, there's essentially no difference in overall bulk. The small
differences in weight and and length between the lenses make no appreciable difference to the handling,
either. The main difference lies in the 18-35mm's internal zoom design, whereas most 24-70mm F2.8s
extend substantially on zooming.
Aug 15, 2013
Aug 12, 2013
Autofocus
The 18-35mm uses Sigma's 'Hypersonic Motor' for autofocus, which is fast, essentially silent, and generally
very decisive. The focus can be adjusted manually when the lens is set to AF without fear of damaging its
innards. Our sample showed no obvious problem with systematic front- or back-focusing, but we did have
some problems with focus consistency when shooting at large apertures (described later in the review).
Aug 9, 2013
The 18-35mm also works pretty well for live view autofocus, although this is highly dependent upon the
camera being used. In video mode, it's not too bad either, indeed probably one of the better SLR lenses
we've used. But if you use autofocus during movie recording in a quiet situation, the camera's built-in
microphone will be liable to pick up the ticking of the lens's AF motor on your soundtrack.
Pentax Q7
Aug 8, 2013
Lens body elements
70%
The lens is initially available in Canon,
Nikon and Sigma mounts, as tends to be
the case from Sigma. Sony and Pentax
models will appear later.
MACRO OS HSM | C
Aug 5, 2013
Our review sample was in Canon EF
mount. Unlike Canon's own EF-S lenses it
will physically mount on full frame SLRs,
but will show substantial vignetting at all
focal lengths.
80%
See more...
Latest news
The filter thread is 72mm, and doesn't
rotate on focusing. It's surrounded by a
bayonet mount for the petal-type lens
This week
Mobile madness? Our opinion on Sony's QX clipon cameras
hood.
The manual focus ring feels beautifully
smooth, and rotates about 110 degrees
from infinity to closest focus. The finelyridged rubber grip is about 26mm wide.
The 21mm-wide zoom ring has a
pleasant, fluid movement. It glides
smoothly without any play and feels
correctly damped, giving a real
impression of quality. It rotates 50
degrees from 18 to 35mm, with
additional markings at the 20, 24 and
28mm positions.
A large switch on the side of the lens
barrel sets the focus mode. Like on the
35mm F1.4 DG HSM, when it's set to
autofocus (as here) the inlay behind it is
white; when switched across to MF the
inlay is black. This allows an easy visual
check of its position even in low light.
Here you can also see the 'Made in Japan'
label - not something you'll find on all
lenses any more.
The bayonet-mount hood is provided as
standard, and clicks positively into place
on the front of the lens. It's made from
thick plastic, and features ribbed
moldings on the inside to minimize
reflections of stray light into the lens.
Sigma has even added a ribbed grip to
make it easier to remove.
A broad ridged grip covers most of the
underside of the barrel between the zoom
and focus rings, and provides positive
handling when changing lenses.
Sony reveals QX10 and QX100 camera modules
for smartphones
cameras
prosecution
in-depth review
underwater housing
USB Dock compatibility
The 18-35mm is compatible with Sigma's unique USB dock, a relatively inexpensive accessory (£40 / $59 /
€60) which allows you to hook Sigma's latest lenses up to a computer - click here to read our quick review.
Using the Sigma Optimization Pro software you can then apply detailed autofocus microadjustments if you
find your lens consistently mis-focuses on your camera (which can be something of an occupational hazard
for SLR users). There's also an option to update the lens's firmware, if it should become necessary in the
future.
Sigma's USB Dock and Optimization Pro software lets you set AF microadjustments for four focal
lengths each at four different focus distances.
In principle this allows you to calibrate the lens's focusing specifically for your camera, and help you get the
best possible results. Unfortunately, though, the software comes with limited documentation, and specifically
no instructions on how you might set about determining the microadjustment values you need to set. So we
wonder how many users will really be able to make the most of it.
2. Design and Operation
Editorial content
Camera reviews
Lens reviews
Printer reviews
Previews
Sample images
Articles
Glossary
Link directory
Videos
Product database
Cameras
Lenses
Printers
Software
Smartphones
Camera search
Camera comparison
Lens search
Product timeline
Browse all products
Community
Forums
Challenges
Galleries
Polls
My Profile
My Settings
My GearList
About us Write for us Advertise with us FAQ Feedback Interest-Based Ads Privacy Legal
All content, design, and layout are Copyright © 1998 - 2013 Digital Photography Review All Rights Reserved. Reproduction in whole or part in any form or medium without specific written permission is prohibited.
Mobile site
QUICK LINKS:
News
Reviews
Buying Guide
Sample Images
Videos
Articles
Sample Images
Cameras
Camera Timeline
Lenses
Phones
Link Directory
Printers
Software
Forums
Galleries
Challenges
3. Test results
Studio Tests
The Sigma 18-35mm F1.8 DC HSM turns in an exceptional performance in our studio tests, in essence
matching a selection of high quality primes. It's remarkably sharp, even wide open, and both chromatic
aberration and vignetting are relatively low. Distortion is kept pretty well under control too. Overall this is
very, very impressive indeed.
Test data provided by DxOMark
Sigma 18-35mm F1.8 DC HSM on Canon EOS 7D
Lens review studio test data
Click here to compare this lens with others in a new window.
Sharpness/CA
Vignetting
Distortion
Log in to dpreview
18
8
Focal length:
Options:
20
0
2
24
4 Aperture:
18
1.8
2
Pages
2
2.8
.8
8
Show graphs
Focal length: 18mm
Aperture: f/1.8
Measured focal length: 18.1 - 32.8mm
Maximum transmission: T/1.8 - 1.9
18mm: T/1.8
View full lens data on DxOMark
help
| fullscreen
| compare
Sharpness
The 18-35mm is remarkably sharp even wide open at F1.8, and in the
wider half of its range (18-24mm), there's no measurable increase on
stopping down (i.e. the lens is effectively diffraction limited). At the
longer end (28-35mm) there's a slight improvement in sharpness on
stopping down to F4, but in practice it's unlikely to be especially
noticeable. For an F1.8 zoom, this is little short of astonishing.
Chromatic
Aberration
Lateral chromatic aberration is pretty low. The graphs indicate a little
green/magenta fringing at wideangle, and moderately strong blue/yellow
fringing in the middle of the range (note though that this tends to be
visually less intrusive). At the long end, chromatic aberration is essentially
nonexistent.
Vignetting
Vignetting is remarkably low for such a fast lens, reaching just 1.3 stops
wide open at all focal lengths. It also essentially disappears by F2.8.
Overall it's unlikely ever to be problematic in real-world use.
Introduction
Design and...
Test results
Test results
Overall...
Conclusion...
Distortion
Distortion is kept reasonably well under control - it certainly doesn't
exceed what we'd expect for this kind of lens. There's visible barrel
distortion at wideangle, turning to pincushion distortion at the long end,
but no more than you'd get from any other premium standard zoom.
Lens test data compared
To get a bit more perspective on just how good the 18-35mm is, let's compare it to a couple of benchmark
lenses, using the comparison tool in our lens data widget. Click on the images below to open side-by-side
comparisons in a new window or tab.
Preview...
Compared to Sigma 35mm F1.4 DG HSM
Latest reviews
Sep 2, 2013
86%
The Sigma 35mm F1.4 DG HSM impressed us hugely when we reviewed it at the end of last year, and is
probably the sharpest 35mm F1.4 prime on the market. When tested on the same camera, the zoom may be
just fractionally less sharp at large apertures, but you probably wouldn't see any difference in real world
shooting. The zoom also has slightly higher vignetting and distortion, but lower chromatic aberration. From
this data, you'd be hard pushed to see any meaningful differences between the two in side-by-side shooting.
Remember this is the 18-35mm's weakest focal length.
Sony Alpha A3000
PREVIEW
Aug 26, 2013
Compared to Tamron 24-70mm F2.8 Di VC USD
Canon EOS 70D
PREVIEW
Aug 15, 2013
Aug 12, 2013
Aug 9, 2013
Pentax Q7
Aug 8, 2013
70%
The Tamron 24-70mm F2.8 Di VC USD is probably the best value fast 'normal' zoom for full frame cameras,
and like the Sigma 35mm F1.4, we had no hesitation in awarding it a Gold Award in our recent review. Not
only does it offer built-in image stabilization, optically it comes as near as makes no difference to its Canon
and Nikon counterparts, which are both much more expensive.
MACRO OS HSM | C
Aug 5, 2013
These lenses can be compared in several different ways, but its clear that regardless of whether we look at
them them both tested on the same camera body, or at how the Sigma on APS-C compares to the Tamron
on full frame, the 18-35mm easily holds its own in these studio tests.
80%
Compared to Canon EF-S 17-55mm f/2.8 IS USM
See more...
Latest news
This week
for smartphones
cameras
prosecution
in-depth review
underwater housing
Canon's EF-S 17-55mm f/2.8 IS USM is a highly regarded fast normal zoom for APS-C SLRs, and in
comparison to the Sigma, offers an extended zoom range and built-in image stabilization, which makes it a
very flexible lens indeed. But when we compare the two purely in terms of image quality, it's clear that not
only is the Sigma noticeably sharper than the Canon when both are set to F2.8, it's actually sharper at F1.8
than the Canon is at F2.8. In all other respects, it matches up well too.
3. Test results
Editorial content
Camera reviews
Lens reviews
Printer reviews
Previews
Sample images
Articles
Glossary
Link directory
Videos
Product database
Cameras
Lenses
Printers
Software
Smartphones
Camera search
Camera comparison
Lens search
Product timeline
Browse all products
Community
Forums
Challenges
Galleries
Polls
My Profile
My Settings
My GearList
Mobile site
QUICK LINKS:
News
Reviews
Buying Guide
Sample Images
Videos
Articles
Sample Images
Cameras
Camera Timeline
Lenses
Phones
Link Directory
Printers
Software
Forums
Galleries
Challenges
4. Test results
Studio Tests (continued)
Macro Focus
Macro - 87 x 58 mm coverage
Measured magnification: 0.26x
Distortion: Negligible
Minimum focus distance*: 26.5cm
Working distance**: 10.0cm
Focal length: 35mm
* Minimum focus is defined as the distance from the camera's sensor to the subject
** Working distance is measured from the front of the lens to the subject
Log in to dpreview
We wouldn't necessarily expect a relatively short, fast zoom to be great for close-ups, but the Sigma acquits
itself pretty well. Its minimum focus distance in manual focus mode is an impressively close 26.5cm,
resulting in a somewhat higher maximum magnification than you'll get from a typical 24-70mm F2.8 zoom.
Close-up image quality isn't bad either, at least when stopped down a bit. The image is soft wide open, but
sharpens up pretty well in the centre at F2.8. The corners rather lag behind, but continue to improve on
stopping down until our flat test chart shot looks sharp corner-to-corner at F11. There's minimal distortion,
and only the slightest hint of blue/yellow chromatic aberration.
Colour balance
Third party lenses sometimes find themselves criticized for their colour balance and rendition compared to
the camera manufacturers' own optics. We've looked into this by shooting an X-Rite Colorchecker Passport
using the 18-35mm side-by-side with the Canon EF 24-70mm f/2.8L II USM. The images were shot under
controlled fluorescent lighting, and a custom white balance set from the Passport's own grey card using the
Canon lens. Images were shot in RAW on the EOS 700D, and converted in ACR using identical settings.
Pages
Introduction
Design and...
Test results
Test results
Overall...
Conclusion...
Canon EF 24-70mm f/2.8L II USM
If you compare the colours in this rollover, we think you'll really struggle to see any significant differences
between the two lenses at all. This doesn't come as much of a surprise to us, but it might to some sceptics.
Flash shadowing
One problem we might expect to see, given the lens's sheer physical length, is shadowing of the built-in
flash at wideangle. This is indeed visible; on recent SLRs like the Canon EOS 700D, which lift the flash quite
high above the lens, we saw some shadowing right at the bottom edge of the frame at focus distances. At
the distances you'd most likely use the flash (~2 metres) it's pretty minor though, and effectively disappears
if you zoom in a little bit, to just 20mm.
Preview...
With the EOS 700D, the 18-35mm gives
visible flash shadowing at the bottom of the
frame at 18mm and ~2m subject distance.
But it's not too severe, and can be avoided by
zooming in to just 20mm.
Of course with the lens's super-fast aperture,
you may not use flash very much at all for
indoor shooting.
Full Frame Coverage
The Canon, Nikon and Sony mount versions of this lens will mount on full-frame DSLRs, and on Nikon
cameras DX crop mode will be automatically selected (the camera will therefore shoot at reduced resolution).
The rollover below shows the level of vignetting on full frame, with samples shot on a Canon EOS 6D
through an Expodisc white balancing filter. The lens's image circle doesn't cover the 35mm full frame format
fully at any focal length, giving severe vignetting at 18mm which decreases progressively on zooming in.
There's still visible vignetting in the corners at 35mm, which doesn't entirely go away on stopping down,
either.
Latest reviews
Sep 2, 2013
86%
Sony Alpha A3000
PREVIEW
Aug 26, 2013
Canon EOS 70D
PREVIEW
Aug 15, 2013
Aug 12, 2013
Aug 9, 2013
18mm F1.8
24mm F1.8
35mm F1.8
18mm F8
24mm F8
35mm F8
Pentax Q7
Aug 8, 2013
70%
Here's what the lens looks like shooting a real-world subject at 35mm on the EOS 6D. At F1.8 there's severe
vignetting, pronounced pincushion distortion, and the corners are distinctly soft. At F8 things have cleaned
up substantially, but there's still visible vignetting in the extreme corners, and of course the distortion
remains. This is no surprise for an APS-C lens on full frame - it's simply not designed for the job. But you
could use it at a pinch as a 35mm lens if necessary.
MACRO OS HSM | C
Aug 5, 2013
80%
See more...
Latest news
This week
Canon EOS 6D, 35mm F1.8
Canon EOS 6D, 35mm F8
Background blur compared
One of the great attractions of fast
s lenses is the ability to isolate a subject by blurring the background. At
A
first
s sight the 18-35mm may look like the ideal choice for such work - for any given angle of view it'll give
noticeably more background blur at F1.8 than you'd get from an F2.8 zoom, and indeed match F2.8 on full
frame. However, its relatively limited range means that a 17-50mm F2.8 can actually give better results if you
compare both lenses shot wide open at their long end, purely in terms of the amount of background blur.
This is illust
s rated in the rollover bellow.
APS-C,
C 35mm F1.8
APS-C,
C 35mm F2.8
FF,
F 55mm F2.8
APS-C,
C 50mm F2.8
Here you can see the extra blurring you can get from shooting at 35mm F1.8 compared to what you'd get
from an F2.8 zoom at the same focal length. It's also clear that the F1.8 zoom off
f ers essentially the same
background blur as shooting at an equivalent focal length and F2.8 on full frame. However, if you shoot at
50mm F2.8 on APS-C, moving the camera back to keep the subject size the same, then the background ends
up looking just
s as blurred and less cluttered due to the narrower angle of view. What this means is that a
lens of the 17-50mm F2.8 type is st
s ill a better choice for shooting head-and-shoulders port
r raits.
Similar arguments apply for low light, high ISO shooting; the F1.8 zoom allows you to shoot handheld at
lower ISOs for better image quality, and in principle should come close to matching a full frame camera with
an F2.8 zoom in terms of overall image noise. But there are lots of complicating factors here, including the
exist
s ence of image-st
s abilized F2.8 zooms that allow you to hand-hold at slow shutter speeds and use even
lower ISOs, just
s as long as your subject isn't moving. (Sony and Pentax users, of course, benefit from image
s abilization with all lenses.)
st
Video Autofo
f cus
The Sigma 18-35mm F1.8 HSM uses a ring-type ultrasonic motor, which provides reasonably smooth
autofocusing should you wish to change your focus point during movie recording. The focus motor is
relatively quiet but it's not silent, so the camera's built-in microphone may well pick it up. Both the AF
perf
r ormance, and how audible the lens's operation ends up on your soundtrack, will be dependent upon the
camera used.
The examples below show movie mode AF on the Canon EOS 100D, which allows refocusing on a new
subject by touching the rear screen during recording. Its Hybrid AF sy
s st
s em is also one of the better
implementations of movie focusing on an SLR. Ov
O erall the Sigma does OK here, at least
s for an SLR lens that's
primarily designed for st
s ills photography. Focusing is pretty positive, but the motor can be heard in a quiet
environment.
Sample 1 - Quiet indoor environment
Here we st
s art
r with focus on the left
f side figure, then switch the right side and back again. In a quiet room
indoors, the clicking of the focus motor is clearly audible on the soundtrack.
Sony reve
v als QX10 and QX100 camera modules
for smartphones
DxO Optics Pro 8.3.1 adds support for five
Dx
v recent
cameras
prosecution
Microsoft to acquire Noki
k a's smartphone business
DxOMarkk tests C anon EOS 70D sensor and l enses
Back to the future: ten one-of-a-ki
k nd cameras
i n-d
depth
h revii ew
and white film deve
v lopment
underwater housing
Sigma 18-35mm f/
f 1.8 DC HSM video autofocus - quiet indoor environment
Sample 2 - Outdoor environment with nearby traffic
Here we st
s art
r with focus on the foreground, then switch the background and back again. This is recorded in
a park with nearby traff
f ic, which in this case drowns out the motor noise.
Sigma 18-35mm f/
f 1.8 DC HSM video autofocus - outdoor environment with nearby traff
f ic
4. Test results
Edittorial conttentt
Cam
mera revie
ews
L nss revviewss
Le
Printter reviews
Prevviewss
Sam
mple i mag
ges
A rticcles
Glosssaryy
Link dire
ectory
V ide
eos
Pro
oduct
c data
abasse
Cam
mera
as
L nses
Le
Prin
nterss
Softwarre
Sma
artph
hone
es
Cam
mera
a sea
arch
Cam
mera
a com
mparrison
n
L ns search
Le
h
Productt timeline
e
Browse al l products
Co
omm
mun
nity
Forrumss
Challen
ngess
Gallerie
es
Poll ls
Myy Proff ile
Myy Setttingss
Myy Gea
arListt
Connecct with dprrevie
ew
Subsccribe
e to the weekkly ne
ewslette
er
About us Write for us Adve
v rtise with us FAQ Feedback Interest-Based Ads Priva
v cy Le
L gal
All content, design, and layo
y ut are Co
C pyright © 1998 - 2013 Digital Photography Review All Rights Reserv
rved. Reproduction in whole or part
r in any form or medium without specific written permission is prohibited.
Mobile site
QUICK LINKS:
News
Reviews
Buying Guide
Sample Images
Videos
Articles
Sample Images
Cameras
Camera Timeline
Lenses
Phones
Link Directory
Printers
Software
Forums
Galleries
Challenges
5. Overall Image quality
Overall image quality
The 18-35mm delivers such extraordinary results in studio testing that it barely seems believable. However in
real-world shooting it is genuinely capable of delivering wonderfully detailed images when shot wide open,
at least when it's properly focused. This is shown in the examples below, which were shot at each end of the
zoom, then converted from RAW with sharpening turned off in ACR and a relatively modest small-radius
unsharp applied in Photoshop to bring out fine detail (amount = 150, radius = 0.3).
Canon EOS 100D, RAW + ACR
Log in to dpreview
18mm F1.8
35mm F1.8
100% crop, lower centre
100% crop, centre
Pages
100% crop, lower right
Introduction
Design and...
Test results
Test results
Overall...
Conclusion...
100% crop, bottom right corner
At 18mm sharpness remains impressively high out to the edge of the frame, although green/magenta
chromatic aberration becomes quite visible. Sharpness visibly drops right in the extreme corners, but most of
the time you'll lose much more sharpness to the limited depth of field at F1.8 than you will to lens
aberrations.
At 35mm F1.8 things are slightly different- if you shoot a flat scene straight-on you'll see a gradual drop-off
in sharpness right across the frame. But this mainly due to curvature of field, so if you shoot something
three-dimensional then objects in the extreme corners will look sharp if they happen to be in focus. The lens
shows practically no chromatic aberration at 35mm, either, which means that the images look very clean
indeed. Overall, this kind of image quality is remarkable coming from an F1.8 zoom.
Autofocus accuracy and consistency
One real problem we had in real-world shooting with the 18-35mm was with autofocus. Depth of field is
limited at F1.8 - especially at 35mm - which means that even slight misfocusing can become very visible if
you look closely at your images. We shot with a range of Canon SLRs, from the entry-level EOS 100D to the
top-of-the-line EOS 7D, and all had problems focusing absolutely correctly all the time. This was usually only
obvious when shooting at apertures larger than F2.8. In general, we got slightly better results by using the
central AF point (with recomposition) compared to using off-centre AF points, but this didn't eliminate focus
errors entirely.
Preview...
The example below is typical of the kind of focus problem we saw. These two images were shot just a
second apart, but while the top one is in more-or-less perfect focus, the other is slightly off - the camera has
actually focused somewhat in front of the statue. This type of misfocusing seems most prevalent with
relatively low-contrast subjects, and is often enough to take the edge off the sharpness. This means it can be
difficult to make the most of the lens's excellent optics.
Canon EOS 700D, 35mm F2, 1/4000 sec ISO 200
Latest reviews
Sep 2, 2013
86%
Sony Alpha A3000
PREVIEW
Aug 26, 2013
Canon EOS 70D
PREVIEW
Aug 15, 2013
Aug 12, 2013
When pinning down what's going on here, we have to draw a distinction between focus accuracy and
consistency. Point an SLR at the same subject and autofocus 10 times while looking through the optical
viewfinder, and it'll probably give 10 slightly different results. How close it comes on average to focusing
correctly defines the accuracy, whereas the spread of focus distances describes the consistency.
Aug 9, 2013
We're not going to delve in detail into why this happens, however it boils down to the fact that SLRs don't
use the main image sensor itself for focusing (except when in live view), but instead a different sensor with
its own light path. This arrangement can give rise to both random misfocusing, and more systematic focus
errors. The latter can to some extent be fixed using the 'Autofocus Microadjustment' settings in many modern
SLRs, and offered in a more advanced form by Sigma with its USB Dock and Optimization Pro software.
Pentax Q7
Aug 8, 2013
70%
A consequence of all of this is that in principle you'll get the very best results at large apertures by focusing
and shooting in live view. This has its own pitfalls though - for example when focusing manually with
Nikon's DX SLRs you have to remember to set the aperture to F1.8 before entering live view, as they're
incapable of adjusting the lens's diaphragm during viewing. If you initiate live view at a smaller aperture,
then you risk getting misfocused images. Meanwhile Canon users may have to set the aperture to F1.8 and
press the depth of field preview button to force the lens wide open for accurate manual focusing, when
shooting in bright light.
MACRO OS HSM | C
Aug 5, 2013
80%
Autofocus microadjustment
We looked at whether the focus problems we saw from the 18-35mm could be mitigated by using autofocus
microadjustments. With a Sigma USB Dock to hand, we set about determining and programming in a full set
of autofocus microadjust parameters for all of Sigma's specified focal lengths and focus distances (18, 24,
28 and 35mm; infinity, 0.5m, 0.35m and 0.28m). This took several hours to set up, even with specialised
focusing targets to hand. The screenshot from Sigma Optimization Pro below shows the adjustments we
ended up with (note that every copy of the lens is expected to require different numbers).
See more...
Latest news
This week
for smartphones
cameras
prosecution
in-depth review
underwater housing
This procedure certainly improved overall focus accuracy when shooting at the distances used for
microadjustment. However these are fixed by the software, and there's no option to specifically correct any
distance between infinity and 0.5m. Unfortunately though, the vast majority of subjects end up somewhere
in between, and we found that the lens still had some problems with focus accuracy even when fully
programmed as above. Knowing this, we'd probably configure the 'Infinity' position with a bias towards
getting the most accurate focus at closer subject distances.
The other take-home message here is that, while our copy of the lens showed a tendency towards focusing
in front of subject (and therefore required positive microadjust values), the correction needed at each setting
was different. So using a global in-camera microadjust value would necessarily be a compromise - setting a
value to correct any given focal length and subject distance could throw off the focus at other settings. We
observed this in practice using the Canon EOS 7D's microadjust feature - it could only be set to give optimal
focusing at one given focal length and subject distance.
Are we looking too closely?
One point implicit in all of these discussions is that we're examining images for pixel-level sharpness, which is
a hugely demanding criterion. Images don't necessarily have to be this perfectly focused to be entirely
acceptable when viewed on-screen or made into in anything other than very large prints. So while accurate
autofocusing is highly desirable, slight misfocus doesn't necessarily spoil a photograph completely. This is
where each individual photographer has to make their own decision about what they're prepared to accept,
based on personal experience and preference.
However, we believe most potential buyers for this lens will be demanding users - either serious enthusiasts
or professional photographers. And while we think that they'll be delighted with the image quality the lens
delivers when properly focused, they won't generally find this kind of hit-and-miss focusing at F1.8 very
acceptable; the lens just doesn't reliably deliver usable images every time. This doesn't mean that there's no
point in buying the lens at all - its outright image quality at normal working apertures is reason enough to
get one - but it does mean that we'd recommend testing before you buy, if at all possible. Of course we've
only used the Canon mount version of the lens - it's possible other versions may work better.
Specific image quality issues
As always, our studio tests are backed up by taking hundreds of photographs with the lens across a range of
subjects, and examining them in detail. This allows us to confirm our studio observations, and identify any
other issues which don't show up in the tests. In real-world shooting the Sigma 18-35mm produces
consistently excellent results - just as long as the camera can focus it accurately enough.
Chromatic aberration
The 18-35mm doesn't show too much in the way of chromatic aberration, but it's visible if you go looking
for it. Under different conditions it can show the two main types of CA, lateral and longitudinal.
Lateral chromatic aberration is visible as colour fringing towards the edges and corners of the frame, and as
usual is strongest at wideangle. It tends to be most obvious when the lens is stopped down a bit, which
brings the fringing into sharpest focus. It's relatively easy to correct in post-processing, but will be visible in
most cameras' JPEG output (although many Nikon SLRs will automatically remove it).
The Great Court of the British Museum is something of a torture test for this type of CA, and in the
uncorrected example below you can clearly see green/magenta fringing across much of the roof structure
when viewing the image up-close. This is simple enough to correct in most RAW converters - here we're
using Adobe Camera RAW's 'Remove Chromatic Aberration' control.
RAW + ACR, no correction
RAW + ACR, CA corrected
Canon EOS 100D, 18mm F5.6, 1/100sec ISO 100
100% crops, upper left
Longitudinal chromatic aberration can also be visible occasionally, as colour fringing around out-of-focus
areas of the frame when shooting at large apertures. This tends to be strongest at the long end of the zoom,
but is never very objectionable. The example below illustrates just about the worst case scenario, with red
fringing in front of the plane of focus, and green fringing behind, accentuated by the grass being overexposed. This type of CA is generally less straightforward to remove in post-processing, as it shows up
differently in every image.
100% crop in front of focus plane
Canon EOS 100D, 35mm F1.8
100% crop behind focus plane
Overall though, this level of chromatic aberration is impressively low, especially considering that we're
looking at an ultra-fast zoom. It's no worse than we'd expect to see from fast primes, either.
Flare
The 18-35mm does reasonably well with respect to flare, given its fast aperture and the sheer amount of
glass used in its construction. In real-world use shooting in bright mid-summer sun we've not seen any
obvious problems, but the usual caveats apply - it's essential to keep the front element clean, and always
best to shoot with the hood in place too. The examples below give an idea of how the lens deals with the
sun in or around the frame.
In the first set we're shooting at wideangle with the sun in the corner of the frame, and comparing what we
see with lens shot wide open and then stopped right down to make flare patterns most defined. Here the
results depend upon the aperture; image contrast is maintained well at F1.8, and holds up on stopping down
to about F4. Diagonal flare patterns become visible at F5.6, and shadow detail starts to deteriorate too. Both
effects becomes more pronounced at smaller apertures, and at F16 we see well-defined and intenselycoloured flare patterns, along with substantial loss of shadow detail.
In the fourth sample we've zoomed in to 35mm and placed the sun just outside the frame. The lens does
particularly well here at maintaining contrast and shadow detail.
18mm, F1.8, sun in corner of frame
18mm, F5.6, sun in corner of frame
18mm, F16, sun in corner of frame
35mm, F5.6, sun just outside frame
Background blur ('bokeh')
One genuinely desirable, but difficult to measure aspect of a lens's performance is the ability to deliver
smoothly blurred out-of-focus regions when trying to isolate a subject from the background, generally when
using a long focal length and large aperture. The 18-35mm gives you a decent degree of control over depth
of field due to its large maximum aperture.
As always you'll get the most-blurred backgrounds shooting at the long end of the zoom, and here the 1835mm's rendition of out-of-focus areas tends to be pretty attractive. The examples below give some idea of
what to expect. In the first the subject distance is somewhere around 3m, which means that the degree of
background blur isn't huge. But it's sufficient to focus attention on the fountain, and the blurring is
generally attractive.
You'll get much more background blur when shooting at close focus distances, as always, and this is shown
in the second example. Again the effect is smooth, although here the just-out-of-focus regions in the lower
half of the frame show slightly harsh edges.
Distant Bokeh
35mm F1.8, Canon EOS 100D
Close-up Bokeh
35mm F1.8, Canon EOS 100D
Background detail, upper centre
Detail crop, upper centre
Overall though, the lens's wideangle-to-normal focal length range means that it can't match a cheap 50mm
F1.8 prime if getting strongly-blurred backgrounds is a top priority.
5. Overall Image quality
Editorial content
Camera reviews
Lens reviews
Printer reviews
Previews
Sample images
Articles
Glossary
Link directory
Videos
Product database
Cameras
Lenses
Printers
Software
Smartphones
Camera search
Camera comparison
Lens search
Product timeline
Browse all products
Community
Forums
Challenges
Galleries
Polls
My Profile
My Settings
My GearList
Mobile site
QUICK LINKS:
News
Reviews
Buying Guide
Sample Images
Videos
Articles
Sample Images
Cameras
Camera Timeline
Lenses
Phones
Link Directory
Printers
Software
Forums
Galleries
Challenges
6. Conclusion and Samples
Conclusion - Pros
Super fast constant F1.8 maximum aperture
Excellent optics, even wide open
Fast, silent autofocus
Solid build quality without being over-heavy
Compatible with Sigma's USB dock and Optimization Pro software
Conclusion - Cons
Restricted zoom range
Needs detailed AF microadjustment for best results
Inconsistent autofocus in difficult conditions even after microadjustment
Physically rather large for a standard zoom
Overall conclusion
The Sigma 18-35mm F1.8 DC HSM was announced to widespread excitement, if only for the company's
sheer ambition in making such a fast zoom. But this inevitably came with a degree of scepticism - it's hard
enough to make an F2.8 zoom that's really sharp wide open, so could an F1.8 zoom possibly work? Then
again, Sigma's recent track record with lenses like the wonderful 35mm F1.4 DG HSM gave hope that the
company might possibly be able to deliver.
Log in to dpreview
What nobody quite anticipated, ourselves included, was that Sigma could conceivably deliver a lens with
optics this good. The 18-35mm isn't just sharp for a fast zoom; in terms of outright image quality, it's a
match for many fast primes, even when shot wide open. Obviously, the restricted zoom range will have
helped, but even so this is a considerable achievement on Sigma's part. The lens can more-or-less replace a
set of primes across its range with minimal compromise in image quality.
This does all come with one serious caveat though, and that's to do with focusing. We've used two copies of
the Canon mount version of the lens, and found autofocus to be rather hit-and-miss with both under lessthan-ideal conditions (for example with low contrast subjects). Part of the problem here is that the kind of
relatively small focus errors sufficient to take the edge off the image sharpness at F1.8 are essentially invisible
in the optical viewfinders of SLRs, so it's difficult to spot focus errors while you're shooting. Setting up full
AF microadjustment using Sigma's USB dock and Optimization Pro software certainly helps with overall focus
accuracy, but doesn't eliminate shot-to-shot inconsistency.
What this means is that while the 18-35mm has truly superb glass, autofocus problems mean that it can be
difficult to get the full benefit when shooting at large apertures, which somewhat negates the lens's key
selling point. Not every wide-open shot will be misfocused by any means, and you'll still get prime-like image
quality when shooting stopped-down. But unfortunately, the fact that you can't rely on always getting
correct focus makes the lens a bit less easy to recommend over an F2.8 zoom in the 17-50mm class.
This is unfortunate, because in almost every other respect the Sigma is an excellent lens. It handles well,
with smooth zoom and focus rings and all of Sigma's latest thoughtful design touches. In terms of the less
easily quantifiable aspects of image quality, it offers attractively-blurred backgrounds, and isn't overly
susceptible to flare given its speed. And, of course, it's not just the fastest zoom on the market, but faster
than almost any prime wider than 24mm that you can mount on an SLR (with the sole exception of Sigma's
own venerable 20mm F1.8).
Pages
The Final Word
Sigma has been on something of a roll recently, with lenses like the 35mm F1.4 offering excellent optics at a
very competitive price, and it's clear from both technical tests and real world shooting that the 18-35mm
F1.8 is following on in much the same vein. Its relatively narrow zoom range is undeniably a little restrictive,
but on the other hand, the image quality it can offer over that range is absolutely stellar. It's let down a little
by inconsistent autofocus, which makes it difficult to get consistently sharp results every time when shooting
wide open. But if you're prepared to live with this, the 18-35mm is capable of delivering truly exceptional
results.
Category: Normal Lens
Poor
Optical Quality
Build Quality
Autofocus
Introduction
Design and...
Test results
Test results
Overall...
Conclusion...
Compare mode
OFF
Excellent
Ergonomics and Handling
Value
Good for
Not so good for
Overall score
86%
Enthusiast APS-C users looking for the very best
image quality available from a normal zoom, and
willing to spend a bit of time setting up autofocus
micro-adjustments or using live view focusing for
the sharpest results.
Photographers who like to travel light, or need a
wide-ranging zoom.
Preview...
The Sigma 18-35mm F1.8 DC HSM is an
extraordinary lens, offering prime-level
image quality in the fastest zoom ever made
for SLRs. Its 28-50mm equivalent range is a
little limiting though, and inconsistent
autofocus means that it can be difficult to
make the most of the excellent optics when
shooting at large apertures.
Latest reviews
Sep 2, 2013
Want to make sure you don't miss out on any future reviews?
Sign up for our free weekly newsletter!
86%
Enter the 'Third Party Lens Talk' Discussion Forum
Recommended links
Sony Alpha A3000
Sigma 18-35mm F1.8 DC HSM | A on DxOMark
Sigma 35mm F1.4 DG HSM lens review
Tamron 24-70mm F2.8 Di VC USD lens review
PREVIEW
Aug 26, 2013
Samples Gallery
Canon EOS 70D
There are 45 images in the review samples gallery and 34 images in the preview samples gallery. Please do
not reproduce any of these images on a website or any newsletter / magazine without prior permission (see
our copyright page). We make the originals available for private users to download to their own machines for
personal examination or printing (in conjunction with this review), we do so in good faith, please don't
abuse it.
PREVIEW
Aug 15, 2013
Unless otherwise noted images taken with no particular settings at full resolution and processed with
default settings (no lens corrections) in Adobe Camera Raw.
Aug 12, 2013
Aug 9, 2013
Pentax Q7
Aug 8, 2013
70%
MACRO OS HSM | C
Aug 5, 2013
80%
See more...
Latest news
Sigma 18-35mm F1.8 DC HSM | A review samples - 2nd September 2013
This week
for smartphones
cameras
prosecution
in-depth review
underwater housing
Preview Samples Gallery
Sigma 18-35mm F1.8 DC HSM | A preview samples - updated 10th June 2013
6. Conclusion and Samples
Editorial content
Camera reviews
Lens reviews
Printer reviews
Previews
Sample images
Articles
Glossary
Link directory
Videos
Product database
Cameras
Lenses
Printers
Software
Smartphones
Camera search
Camera comparison
Lens search
Product timeline
Browse all products
Community
Forums
Challenges
Galleries
Polls
My Profile
My Settings
My GearList
Mobile site

Sigma 18-35mm F1.8 DC HSM Review

Transcription

Similar documents

The author has no financial interest to disclose. How Many of your

PRO 1600 Reflow Oven: Video Recording and Observation Module

Portatile e senza fili, per uno screening di qualità Portatile e senza

Givi V46 reflective decal installation instructions:

Canon EOS 630 - Earth Sea Publishing

Video Sunglasses, Sports HD 720p Wide Angle

TK-WD9602E

Is There a Science to Law Firm Management and Does Six

HSM T 15007 ROTARY TRIMMER

Bio 1 Lab 2 review Hadley - Biology-Lab-1