The Canon EOS Rebel XSi (EOS 450D) is Canon's latest DSLR and the
most full featured entry level DSLR in their Digital Rebel line of
cameras. It builds on the Digital Rebel XTi but adds a new sensor
(12MP vs. 10MP), a larger LCD screen (3" vs. 2.5"), Live View, Spot
Metering, ISO display in the viewfinder, Highlight Tone priority, High
ISO noise reduction and a number of other software features, which are
also found on the Canon EOS 40D.
Externally, the Rebel XSi and XTi are very similar in size and
shape and share a similar control layout. Due to the larger LCD screen
of the XSi, a number of the control buttons have been relocated, but
the same functionality is retained. To allow the center button of the
rear 4-way controller to now activate the Live View mode, a separate
ISO button has been added next to the main control dial.
Hannah Thiem
For the first time on any EOS DSLR, the Digital Rebel XSi uses
only an SD(HC) memory card for image storage. All previous Digital
Rebels, as well as the EOS 5D/10D/20D/30D/40D have used Compact Flash
memory cards. The 1D series DSLRs have had the capability of using
both SD and CF cards. The change isn't really a big deal since SD
cards (and higher capacity SDHC cards) are now as easily available as
CF cards, cost around the same in $/GB, and can be found in capacities
of up to 16 and 32GB.
Both the XTi and XSi use a pentamirror viewfinder system, but the
viewfinder screen of the XSi is slightly larger and also, to my eye,
appears to be slightly brighter. The difference in size isn't huge,
but every little bit helps. The viewfinder screen of the XSi has a center
circle which makes the area of the spot meter. Both cameras use the
same diamond shape of 9 focus zones.
The Canon Digital Rebel XSi can be purchased from amazon.com in the
following combinations:
If you are new to digital photography, start with the
photo.net article on "Building
a Digital SLR System."
Bob Atkins
Operating Speed
The Digital Rebel XSi is very responsive in terms of operational
speed. The LCD display appears less than a second after the camera is
powered up, but you can take a photo only 250ms (1/4s) after
the power switch is moved to "on" before the LCD screen starts
displaying data.
In continuous capture mode, the Rebel XSi is capable of 3.5
frames per sec (fps) for about 55 frames before the buffer fills and
the rate drops a little. The buffer is significantly smaller when
capturing RAW, and in that case the 3.5 fps drops to around 0.7 fps
after only 6 frames. In RAW+JPEG mode, the buffer only holds 4
captures.
These numbers make the XSi faster than the XTi (3 fps) with a
larger JPEG buffer (55 frames vs. 30 frames). However, the RAW file
buffer is somewhat smaller (6 frames vs. 10 frames), presumably at
least in part due to the larger file size dictated by the higher pixel
count. The EOS 40D is good for 6.5 fps for around 125 JPEGs or around
18 RAW images.
Controls
The Rebel XSi uses a control layout, which should be fairly
familiar to most users. The 3" rear LCD screen is used to display
operating parameters and the various software menus, as well as to
review images. As with previous Digital Rebels, there is no top
mounted LCD screen. Menu navigation is done via the 4-way buttons
(allowing navigation up, down, left and right through the menus). The
center "set" button is also used to enable Live View modes. In Live
View, focusing is enabled by pressing the "*" button. When not being
used for navigation, the 4-way buttons are used to select capturing
mode, metering mode, AF mode, and picture style.
The menu structure is similar to that of the Digital Rebel XTi and
the EOS 40D. Like the 40D there's a customizable menu screen on which
you can place the functions you use most so that you can access them
rapidly. I put Image Quality Selection, Memory Card Format, High ISO
Noise Reduction, Highlight Tone Priority, Mirror Lockup, and Custom WB
there.
For a complete and detailed description of all the camera controls
and options, you can download a
PDF copy of the Rebel XSi user manual.
Auto Focus
The EOS Rebel XSi has a 9-point wide area AF
sensor with the points set in a diamond pattern.
The focus point can be manually selected, or the camera can decide
which AF point(s) to use. There are 4 focus modes: One-Shot AF, AI
Focus AF, AI Servo AF, and Manual. The central AF point is an improved
cross type sensor with high precision for lenses with an aperture of
f/2.8 or faster.
In Live view there are two focus modes. One is the same as that
used on the EOS 40D, where the reflex mirror flips down briefly and
the normal AF sensors are used to achieve focus. This is termed
"quick mode." The second focus mode (only available on the XSi) is
"live mode" and uses a contrast-based AF system. The live image is used
and focus is determined by looking for maximum contrast. It has the
advantage that the LiveView is not interrupted, but it's significantly
slower (focus may take a few seconds) and it may not be quite as
accurate in all situations as quick mode.
Overall, I found that most of the time the AF performance of the
XSi and XTi were quite similar. However, there were some situations in
very low light where the XSi could get an autofocus lock, while with
the same lens under the same lighting, the XTi failed. This is
consistent with a statement found in the press release for the XSi in
which Canon states, "The EOS Rebel XSi Digital SLR utilizes a precise
nine-point Autofocus (AF) system featuring a newly developed AF sensor
that improves the camera's subject detection capabilities compared to
earlier models."
Metering and Exposure
Hannah Thiem
The XSi adds Spot metering to the Evaluative, Partial and
Centerweighted patterns of the XTi. The spot metering area is marked
by a circle on the viewfinder screen.
Digital Rebel XSi metering:
- 35-zone TTL full-aperture metering
- Evaluative metering (linkable to any AF point)
- Partial metering (approx. 9% of viewfinder at center)
- Spot metering (approx. 4% of viewfinder at center)
- Center-weighted average metering
- Range EV 1-20 (at 73°F/23°C with EF 50mm f/1.4 USM lens, ISO 100)
The Rebel XSi has the same Highlight Tone Priority feature
as the EOS 40D. This appears to be a hardware function, which adjusts
the tone curve in order to prevent blowing out highlights in a scene
that would normally exceed the dynamic range of the sensor. Exactly
how Canon does this, they don't say, but it is more than just a
software function. It affects both RAW and JPEG files. It's not a
miracle cure for blown highlights, but it does give you about an
extra stop of latitude at the expense of potentially more shadow
noise. With Highlight Tone Priority enabled, the ISO range is
restricted to 200-1600.
The XSi uses a 14-bit A/D converter, which could in theory give
better tonal gradation, though in practice it's very difficult to see
the difference from 12-bit images (such as those from the XTi).
White Balance
Hannah Thiem
The XSi has the usual set of white balance modes: Auto, Daylight,
Shade, Cloudy, Tungsten, White Fluorescent Light, Flash and Custom. It
doesn't allow color temperature to be set as the EOS 40D does. In
typical Canon fashion, Auto white balance doesn't do great under
tungsten lighting, giving a distinctly yellow image. In tungsten mode
the color balance under domestic tungsten lighting is closer to
neutral, but still noticeably warm. If you want the most neutral color
rendition under tungsten lighting, the custom WB mode is best. In this
mode you first shoot an image of a white or gray card under the
lighting conditions you will be using. The camera can them use this as
a reference for subsequent shots.
LCD Monitor
The XSi has a 3" (diagonal) LCD screen vs. the 2.5" screen of the
XTi. Both have 230,000 pixels, 100% image coverage and LCD brightness
control with 7 levels. The XSi adds the option of 4 different color
schemes for data display - black on white, white on black, light blue
on dark blue and dark brown on light brown.
Viewfinder
The viewfinder of the Digital Rebel XSi is slightly larger than
that of the XTi, but slightly smaller than that of the EOS 40D. The
differences are not huge and you might not even notice them unless you
compared the cameras side by side. The XSi viewfinder also seems
slightly brighter than that of the XTi, but again the difference is
small. Both the Xsi and XTi use a pentamirror system rather than the
more expensive and heavier (but slightly brighter) pentaprism
system.
Like the EOS 40D, the Rebel XSi displays the ISO
setting in the viewfinder at all times, along with the usual
information such as shutter speed, aperture, exposure compensation,
flash status, AF status, buffer frames remaining (when that number is
9 or less), flash exposure compensation setting, high speed sync
setting and exposure lock indication.
The XTi and XSi share the same 9 AF zone markings, but the XSi
viewfinder adds a center circle marking, which defines the area covered
by the new spotmeter in the XSi.
XSi Viewfinder Specifications
Coverage - Vertical/Horizontal approx. 95%
Magnification - Approx. 0.87x (-1m with 50mm lens at infinity)
Eyepoint - Approx. 19mm (from eyepiece lens center)
Dioptric Adjustment Correction -3.0 to +1.0 diopter
Digital Sensor
The Digital Rebel XSi uses a new sensor with 12.2 MP and a maximum
image size of 4272 x 2848 pixels. This is up by about 20% from the
10.1 MP sensors used in the Digital Rebel XTi and EOS 40D (3888 x 2592
pixels) and should theoretically enable about 10% greater linear
resolution.
In practice, there's not a very noticeable difference in image
resolution as you can see from the sample images below. These are 100%
crops from JPEGs taken using the standard default parameters for
sharpness with each camera.
The Rebel XSi may have a slight resolution edge, but
remember these crops represent looking at sections of a very large
image, probably something around 24" x 36" on a typical monitor
screen. Despite the fact that both the EOS 40D and Digital Rebel XTi
have the same pixel count, the EOS 40D image looks a little
sharper. In all three cases, resolution may be increased slightly when
capturing in RAW mode and making the optimal conversion to JPEGs.
The Digital Rebel XSi has "anti-dust" features built into the
sensor, which includes an anti-static coating and an ultrasonic shaker
to dislodge dust particles. There's also a software mapping function,
which can be used to minimize the visibility of dust particles if for
some reason you can't clean the sensor or you want to be absolutely
sure of minimizing the effects of dust.
ISO Settings and Image Noise
Hannah Thiem
Both the Rebel XSi and XTi have an ISO range of 100 to
1600 in full stop steps (100, 200, 400, 800, 1600). The EOS 40D has a
range of from 100 to 3200, with the 100-1600 range covered in 1/3 stop
steps (100, 120, 160, 200 etc.). An Auto ISO mode is available on the
XSi and EOS 40D, but it's limited in its range. In most exposure
modes the range is 100-800, but in manual exposure mode ISO is set to
400 in auto mode. In the basic zone modes (everything except P, Av,
Tv, M and A-Dep), ISO is always set to auto mode and cannot be
manually selected.
In the set of test images below the three cameras are
compared. Again all three cameras were set to their default settings
and no additional noise reduction functions were enabled. These are
100% crops, meaning one pixel on the screen maps directly to one pixel
in the image. Up to ISO 400 all three cameras give very clean images
with little or no evidence of noise. At ISO 800 noise starts to
appear, but is still well controlled. At ISO 1600 noise is much more
visible, with the EOS 40D showing the least noise, followed by the
10MP Rebel XSi and with the 12MP Rebel XTi showing
slightly more noise.
Since a higher pixel count in the same sized sensor usually means
smaller pixels, and since smaller pixels usually show higher noise
levels at high ISO settings, these observations are consistent with
what you would expect. However, noise is still pretty well controlled,
even at ISO 1600 on the XSi and it's low enough that small to medium
sized prints made from the images would be quite acceptable.
A feature of the EOS 40D, which has found its way onto the XSi is a
high ISO noise reduction mode. This appears to increase the amount of
chroma noise reduction while not greatly affecting the luminance noise.
The main downside of enabling high ISO noise reduction is that
the camera can buffer fewer images when capturing in continuous
mode. Presumably this is due to the increased processing power
required for the noise reduction mode leading to slower compression
and storage of images, so the buffer fills faster.
Live View
Hannah Thiem
For the first time in a Digital Rebel series DSLR, Canon has
added Live View to the XSi. Live view gives you a real time image on
the LCD screen, just like a P&S digicam. To do this the reflex mirror
is locked up, and in that position the camera can't use its normal AF
sensors.
The XSi has two different methods of autofocusing while using the
LiveView mode. The first is the same as that used on the EOS
40D. Pressing the "*" button on the back of the camera drops the
mirror down and enables normal AF operation - though the image on the
LCD blanks out during this process. When the "*" button is released,
the mirror flips back up and the LCD displays the image in real time
again. Although this sounds complex, it happens quite fast and Canon
call this the "Quick" AF mode.
The XSi also offers another focus mode (not found on any other
Canon DSLR at the moment), which they call the "Live" mode. In this
mode the image is continuously displayed on the LCD and the camera
uses that image to find focus via a contrast sensing algorithm. The
drawback of this mode is that it can be slow (focus may take several
seconds) and it may not be as sensitive or accurate as the normal
"Quick" AF mode using the dedicated phase detection AF sensors.
It's also possible to use manual focus of course, and the LCD
image can be magnified by 5x or 10x to assist in optimizing focus.
In-Camera Editing
Though you can't actually edit the images in the camera once you
have taken them, you can apply effects to existing images when
printing directly from the camera. These include a "Vivid" mode which
increases saturation for more vivid greens and blues, a noise
reduction mode to lower image noise and three black and white modes
(neutral, warm and cool).
Bob Atkins
The Digital Rebel XSi does have an extensive set of options, which
you can select before an image is taken and affect the resulting
JPEG image. There are preset picture styles (Standard, Portrait,
Landscape, Neutral, Faithful and Monochrome) - all of which can be
edited and modified for sharpness, saturation, contrast and color, as
well as monochrome color filtering simulation (yellow, orange, red and
green). You can also create 3 custom picture styles based on modified
existing styles and you can create entirely new styles with the
provided Picture Styles Editor software.
If you choose to capture in RAW mode, the provided DPP (Digital Photo
Pro) software allows you to apply any picture style to any image
during the RAW conversion process.
Flash
The XSi has a retractable pop-up flash with a Guide number of
13/43 (ISO 100 meters/ft). At ISO 400 with an f/4 lens, the flash range
is around 6.5m (21.5ft). The flash covers the frame seen by a 17mm (or
longer) lens mounted on the XSi. Recycle time is approximately 3
seconds.
The XSi has a standard Canon hotshoe and is compatible with all of
Canon's EX series speedlites (the current models are the
Canon Speedlite 220EX Flash, $125, Canon Speedlite 430EX Flash, $235 and Canon Speedlite 580EX II Flash, $385 (review)). There's
no PC connector for external studio flash, though of course hotshoe to PC adapters
are available. Max sync voltage is 250v and the max sync speed is 1/200s.
Memory Cards
Hannah Thiem
The Digital Rebel XSi uses SD/SDHC memory cards. This is in
contrast to all previous Digital Rebels and the EOS 5D/20D/30D/40D
models, which use Compact Flash (CF) cards. These days, there's little
difference between SD and CF cards in terms of price, capacity and
availability. The fastest CF cards are still faster than the fastest
SD cards, but in a Digital Rebel or even an EOS 40D, the camera can't
write fast enough to make use of the extra speed of the fastest
cards.
The only real issue related to SD/SDHC and CF cards is compatibility
with what you already own. Today, most digital P&S cameras use SD
cards, so if you carry a P&S digicam and an XSi you'll only need to
carry one type of card.
Batteries
The XSi uses Canon Battery Pack LP-E5, which is currently only used
by the XSi. The XTi uses a type NB-2LH battery pack. The new LP-E5 has
higher capacity, but a different form factor so the two types of
battery are not interchangeable.
AC power can be supplied to the XSi via AC Adapter Kit ACK-E5. An
optional Battery Grip BG-E5 is available, which can use 6 AA batteries
or two LP-E5 batteries. It also provides a shutter button and control
dial along with AE/FE Lock, exposure compensation and AF point
selection buttons in a vertical orientation.
Mechanical Design
The Digital Rebel XSi is very similar in size and shape to the
XTi. The edges and corners are slightly more rounded and the
rubberized patches on the back and grip sections of the camera are
slightly rougher and "stickier", making the camera a little easier to
hold with one hand.
- Digital Rebel XSi - 129 x 98 x 62 mm - 524 g (with battery)
- Digital Rebel XTi - 127 x 94 x 65 mm - 556 g (with battery)
Like the XTi, the XSi has a high strength plastic mirror box
mounted in a small stainless steel chassis. The outer panels of the
XSi are made from durable plastic.
Choosing a Lens
Hannah Thiem
The Digital Rebel XSi is available as a kit with the new
Canon EF-S 18-55mm f/3.5-5.6 IS, $170 (review). This lens covers the same angle of
view that a 29-88mm zoom would on a full frame camera, so it's useful
for many types of photography including landscapes, group shots and
portraits. The Image Stabilized (IS) system is a new low-cost version
of Canon's traditional IS, but the performance is good and it can add
up to three stops of stability, making handholding the lens in low
light easier, despite the relatively slow maximum aperture.
To complement the EF-S 18-55/3.5-5.6IS Canon has a new
Canon EF-S 55-250mm f/4.0-5.6 IS, $299 (review), which is good for situations like
sports and wildlife photography where a longer focal length is
needed. It gives an angle of view equivalent to an 88-400mm lens on a
full frame 35mm camera. Like the EF-S 18-55IS, the EF-S 55-250IS uses
a new, lower cost IS system, but again it seems pretty effective
adding up to three stops of stability. Zoomed out to 250mm, IS gives
you a good chance of a sharp image while handholding the camera at
shutter speeds as low as 1/60s.
Of course, for an inexpensive fast portrait lens, you really can't
beat the Canon EF 50mm f/1.8 II, $80 (review). That's a lens I always recommend looking
at.
There are many other lens options from Canon, Sigma, Tamron
and Tokina. For an overview of what's available see The EOS System Guide
Compared to Nikon, Canon, Pentax, Sony
The 12MP Digital Rebel XSi falls between the 10MP Canon Digital Rebel XTi, $545 (review)
and the 10MP Canon EOS 40D, $1133 in
Canon's lineup. The XTi doesn't offer such features as Live View,
spotmetering or Highlight Tone Priority. The EOS 40D offers those,
plus a higher frame rate (6.5 fps vs 3.5 fps), a larger image buffer,
support for studio flash, and a more rugged construction. Which DSLR to
choose depends on your needs and how much you want to pay. All three
cameras are capable of producing excellent image quality, so the
choice should be mainly based on camera features.
Hannah Thiem
In the Nikon lineup the closest cameras to the Digital Rebel XSi
would be the 10MP Nikon D40x, $590 (review)Nikon D40x and the 10MP
Nikon D80, $1000 (review) Nikon D80. The D40x is cheaper, but has a
simpler 3 zone AF system and no provision for the use of Nikon AF-S
(internal ultrasonic motor) lenses. The D80 is closer to the XSi in
terms of features, having an 11-zone AF system, DOF preview and an
optional vertical grip (all of which the D40x lacks). Both the D40x
and D80 have the option of an ISO 3200 setting, which could be a
consideration for those who do a lot of low light work.
The 10MP Pentax K200D, $619, is the closest camera to
the XSi in the Pentax lineup. It offers several features not found on
similar Canon and Nikon DSLRs including sensor-shift stabilization
built into the camera body. This means that all your lenses become
stabilized and you don't need to buy special IS or VR lenses. The K200D
is also sealed against dust and moisture to a greater extent than most
other DSLRs of its class. It features an 11-point AF system and an ISO
range up to 1600. It does not have a Live View capability.
The Sony Alpha A350, $800 (review) offers a 14MP sensor, ISO 3200
capability, an advanced Live View system, a tiltable 2.7" LCD,
sensor-shift stabilization built into the camera body and a 9-zone AF
system. Maximum frame rate is a little slow at 2 fps, but it does pack
in a lot of features for around the same price as the Rebel
XSi.
Rebel XSi Key Features
- 12MP CMOS sensor
- 14-bit A/D conversion
- Digic III processor
- 3" LCD
- Live View with Live Focus
- Highlight Tone Priority
- High ISO noise reduction
- ISO 100-1600 (plus Auto)
- ISO visible in viewfinder
- Flash Sync speed 1/200s
- Spot metering (4%)
- Mirror Lock Up
- Depth of field preview
- Picture Styles
Conclusion
Hannah Thiem
The Rebel XSi seems to be a combination of the Rebel XTi and the
EOS 40D, with a few new features of its own thrown into the mix. It
has the basic form of the XTi with the same shutter speed range, the
same flash sync speed and the same ISO range. However it also has
features of the EOS 40D such as Live View, Highlight Tone Priority,
High ISO Noise reduction, Spot metering, a 14-bit A/D converter and
viewfinder ISO display.
The performance is perhaps closer to the 40D than to the
XTi. Resolution is measurably higher, though the difference in
practice is quite small. Noise appears to be a little higher,
perhaps because of the smaller pixels.
Overall the XSi is an improvement over the XTi, though more in
terms of features than image quality, which is good in both
cameras. Upgrading from the XTi to the XSi makes sense if you need
things like spot metering, a larger LCD and Live View, but if you're
looking for a noticeable leap in image quality, I don't think you'll
see it. If you want a significant increase in image quality, you'd
probably need to look at a full frame DSLR like the
Canon EOS 5D, $1890 (review).
Where to Buy
Amazon.com offers the following Digital Rebel XSi combinations:
More
Canon Digital Rebel XSi Example Photographs
Bob Atkins
|
Canon EF-S 18-55mm f/3.5-5.6 IS (review), set at 43mm,
1/100s, f/11, ISO 800. The use of a small aperture gave enough depth
of field to get both far and near flowers in focus.
|
Hannah Thiem
|
Canon EF-S 55-250mm f/4.0-5.6 IS (review), set at 90mm,
1/160s, f/16, ISO 200. Using continuous capture, I followed a seagull
in flight. If I had used a slightly higher shutter speed, I could have
frozen the motion of the bird. However, at 1/160s the photo has a
sense of movement.
|
Hannah Thiem
|
Canon EF-S 55-250mm f/4.0-5.6 IS (review), set at 154mm,
1/1600s, f/5.6, ISO 200. Even at f/5.6, the EF-S 55-250mm lens creates
a nice out-of-focus background while still capturing detail and vivid
color in the flower.
|
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, April 21, 2008; 02:08 P.M. 
