Summary of differences (ignoring those which are of very little importance):

The 40D:

  • Currently costs around GBP 520 (body only, after 100 cashback from Canon), while the 450D is around GBP 450
  • Has a lower resolution (10 vs 12 megapixels).
  • Has a better viewfinder.
  • Has a faster maximum shutter speed.
  • Uses a pentaprism for its viewfinder (instead of a mirror).
  • Has slightly faster X-sync (something to do with flash).
  • Has 3 custom shooting modes on its dial.
  • Has two different continuous drive modes.
  • Can take more images per second when shooting continuously.
  • Has more custom functions.
  • Has water/dust resistant memory card and battery doors.
  • Takes CF cards rather than SD.
  • Has better battery life.
  • Has interchangable focusing screens.
  • Takes a wireless controller and can do wireless transmission.
  • Is made from magnesium alloy rather than steel/plastic.
  • Is heavier and larger.
  • Has slightly better metering (possibly)
  • Has ISO 3200 (unsure if 450D does).
  • Has slightly better control over white balance (possibly).
  • Does silent shooting in live view mode (unsure if 450D does).
450D 40D
Image Sensor
Type 22.2 x 14.8mm CMOS 22.2 x 14.8mm CMOS
Effective Pixels Approx. 12.2M Approx. 10.1M
Total Pixels Approx. 12.4M Approx. 10.5M
Aspect Ratio 03:02 03:02
Low-Pass Filter Built-in/Fixed with Self Cleaning Sensor Unit Built-in/Fixed with Self Cleaning Sensor Unit
Colour Filter Type Primary Colour Primary Colour
Image Processor
Type DIGIC III DIGIC III
Lens
Lens Mount EF/EF-S EF/EF-S
Focal Length 1.6x Multiplication with EF lens fitted 1.6x Multiplication with EF lens fitted
Focusing
Type TTL-CT-SIR with a CMOS sensor TTL-CT-SIR with a CMOS sensor
AF System / Points 9 AF points (f/5.6 cross type at centre, extra sensitivity at f/2.8) 9 cross-type AF points (f/2.8 at centre)
AF Working Range EV -0.5 -18 (at 23°C & ISO100) EV -0.5 - 18 (at 23°C & ISO100)
AF Modes AI Focus, One Shot, AI Servo AI Focus, One Shot, AI Servo
AF Point selection Automatic selection, Manual selection Automatic selection, Manual selection
Selected AF Point Display Superimposed in viewfinder and indicated on LCD monitor Superimposed in viewfinder and indicated on top LCD panel
Predictive AF Yes Yes
AF Lock Locked when shutter button is pressed half way in One Shot AF mode Locked when shutter button is pressed half way in One Shot AF mode.
AF Assist Beam Intermittent firing of built-in flash Intermittent firing of built-in flash
Manual Focus Selected on lens Selected on lens, default in Live View Mode
Exposure Control
Metering Modes TTL full aperture metering with 35-zone SPC
(1) Evaluative metering (linked to all AF points)
(2) Partial metering at center (approx. 9% of viewfinder)
(3) Spot metering at center (approx. 4% of viewfinder)
(4) Center weighted average metering
TTL full aperture metering with 35 zone SPC
(1) Evaluative metering (linked to any AF point)
(2) Partial metering (approx. 9% of viewfinder at centre)
(3) Spot metering:
Center spot metering (approx. 3.8% viewfinder at center)
(4) Center weighted average metering
Metering Range EV 1-20 (at 23°C with 50mm f/1.4 lens ISO100) EV 0-20 (at 23°C with 50mm f/1.4 lens ISO100)
AE Lock Auto: Operates in 1-shot AF mode with evaluative metering when focus is achieved Auto: Operates in 1-shot AF mode with evaluative metering when focus is achieved
Exposure Compensation +/- 2 EV, 1/2 or 1/3-stop increments +/- 2 EV, 1/2 or 1/3-stop increments
AEB +/- 2 EV, 1/2 or 1/3-stop increments +/- 2 EV, 1/2 or 1/3-stop increments
ISO Speed Equivalent Auto (100-800), 100-1600 (in 1-stop increments) Auto (100-800), 100-1600 (in 1/3-stop increments)
ISO 200-1600 in Highlight Tone Priority (C.Fn II -3) ISO 200-1600 in Highlight Tone Priority (C.Fn II -3)
? ISO can be expanded to H: 3200 (selected in Custom Function)
Shutter
Type Electronically-controlled focal-plane shutter Electronically-controlled focal-plane shutter
Speed 30-1/4000 sec (1/2 or 1/3 stop increments), Bulb (Total shutter speed range. Available range varies by shooting mode) 30-1/8000 sec (1/2 or 1/3 stop increments), Bulb.
Shutter Release Soft touch electromagnetic release Soft touch electromagnetic release
White Balance
Type Auto white balance with the imaging sensor Auto white balance with the imaging sensor
Settings AWB, Daylight, Shade, Cloudy, Tungsten, White Fluorescent light, Flash, Custom.
White balance compensation:
1. Blue/Amber +/-9
2. Magenta/ Green +/-9.
AWB, Daylight, Shade, Cloudy, Tungsten, White, Fluorescent light, Flash, Custom, Colour Temperature Setting.
White balance compensation:
1. Blue/Amber +/-9
2. Magenta/ Green +/-9.
Personal White Balance ? 1 personal WB setting can be registered
WB Bracketing +/-3 levels in single level increments +/-3 stops in full stop increments
3 bracketed images per shutter release. 3 bracketed images per shutter release.
Selectable Blue/Amber bias or Magenta/ Green bias. Selectable Blue/Amber bias or Magenta/ Green bias.
Colour Matrix
Type Two types of colour space, sRGB and Adobe RGB. Two types of colour space, sRGB and Adobe RGB.
Viewfinder
Viewfinder Eye-level SLR (with fixed pentamirror) Pentaprism
Coverage (Vertical/Horizontal) Approx. 95% Approx. 95%
Magnification Approx. 0.87x 1 0.95x1
Eyepoint Approx. 19mm (from eyepiece lens center) 22mm
Dioptre Correction -3 to +1 (1/m) (dioptre) -3 to +1 dpt
Focusing Screen Fixed Interchangeable (3 types). Standard Focusing Screen Precision Matte Ef-A
Mirror Quick-return half mirror (Transmission: reflection ratio of 40:60) Quick-return half mirror (Transmission: reflection ratio of 40:60, no mirror cut-off with EF600mm f4 or shorter)
Viewfinder Information AF information (AF points, focus confirmation light), exposure information (shutter speed, aperture value, ISO speed (always displayed), AE lock, exposure level/compensation, spot metering circle, exposure warning, AEB), flash information (flash ready, high-speed sync, FE lock, flash exposure compensation, red-eye reduction light), white balance correction, SD card information, monochrome shooting, maximum burst AF information (AF points, focus confirmation light), exposure information (shutter speed, aperture value, ISO speed (always displayed), AE lock, exposure level/compensation, spot metering circle, exposure warning, AEB), flash information (flash ready, high-speed sync, FE lock, flash exposure compensation, red-eye reduction light), white balance correction, CF card information, monochrome shooting, maximum burst
Depth of Field Preview Yes Yes
Eyepiece Shutter On strap On strap
LCD Monitor
Monitor 3.0" TFT, approx. 230K dots 3.0" TFT, approx. 230K pixels
Live View Mode with selectable grid. Live View Mode with selectable grid.
? Silent shooting in Live View Mode (2x modes)
Coverage Approx. 100% Approx. 100%
Brightness Adjustable to one of seven levels Adjustable to one of seven levels
Flash
Modes Auto, Manual Flash On/Off, Red-Eye Reduction Auto, Manual Flash On/Off, Red-Eye Reduction
HotShoe / PC terminal Yes/ No Yes/ Yes
X-sync 1/200sec 1/250sec
Red-eye Reduction Yes Yes
Flash Exposure Compensation +/- 2EV in 1/2 or 1/3 increments +/- 2EV in 1/2 or 1/3 increments
Flash Exposure Bracketing Yes Yes
Flash Exposure Lock Yes Yes
Second Curtain Synchronisation Yes Yes
Built-in Flash Range Coverage up to 17mm focal length (27mm equivalent) Coverage up to 17mm focal length (27mm equivalent)
Guide Number (ISO 100, metres) 13 13
External Flash E-TTL II with EX series Speedlites, wireless multi-flash support E-TTL II with EX series Speedlites, wireless multi-flash support
Shooting
Modes Auto, Portrait, Landscape, Close-up, Sports, Night Portrait, No Flash, Program AE , Shutter priority AE, Aperture priority AE, Manual, A-DEP Auto, Portrait, Landscape, Close-up, Sports, Night Portrait, No Flash, Program AE, Shutter priority AE, Aperture priority AE, Manual, A-DEP, Custom (x3)
Photo Effects Monochrome (selected from the "Picture Style" menu) with options for Filters and Toning Effects. Monochrome (selected from the "Picture Style" menu) with options for Filters and Toning Effects.
Drive Modes Single/Continuous Single / Continuous L / Continuous H
Continuous Shooting Max. Approx. 3.5fps. (speed maintained for up to 53 images (JPEG)1, 6 images (RAW))2 Max. Approx. 6.5fps. (speed maintained for up to 75 images (JPEG)1, 17 images (RAW)) 2
Recording Pixels / Compression
Image Size (LF) 4272x2848, (LN) 4272x2848, (MF) 3088x2056, (MN) 3088x2056, (SF) 2256x1504, (SN) 2256x1504, (RAW) 4272x2848 (LF) 3888x2592, (LN) 3888x2592, (MF) 2816x1880, (MN) 2816x1880, (SF) 1936x1288, (SN) 1936x1288, (RAW) 3888x2592, (sRAW) 1936x1288
Compression Fine, Normal, RAW (14bit, Canon original RAW 2nd edition) Fine, Normal, RAW / sRAW (Canon RAW 2nd edition)
File Length
Still Image Format JPEG (Exif 2.21 [Exif Print] compliant) / Design rule for Camera File system (2.0), Digital Print Order Format [DPOF] Version 1.1 compliant JPEG (Exif 2.21 [Exif Print] compliant) / Design rule for Camera File system (2.0), Digital Print Order Format [DPOF] Version 1.1 compliant
RAW+JPEG Simultaneous Recording Yes (RAW + Large JPEG only) Yes
File Numbering (1) Consecutive numbering (1) Consecutive numbering
(2) Auto reset (2) Auto reset
(3) Manual reset (3) Manual reset
Processing Parameters 6 Preset 'Picture Styles' with 3 User defined settings ?
Direct Print
Canon Printers Canon Selphy Printers, Bubble Jet Printers with the direct print function and PIXMA Printers supporting PictBridge Canon Compact Photo Printers and PIXMA Printers supporting PictBridge
PictBridge Yes Yes
Other Features
Custom Functions 13 Custom Functions with 34 settings 24 Custom Functions with 62 settings
LCD Panel (EL) Illumination N/A Yes
Water / Dust Resistance No Yes1
Sound Memo No No
Intelligent Orientation Sensor Yes Yes
Histogram Brightness: Yes Brightness: Yes
RGB: Yes RGB: Yes
Playback Zoom 1.5x - 10x 1.5x - 10x
Display Formats (1) Single image with information (2 levels) (1) Single image with information (2 levels)
(2) Single image (2) Single image
(3) 4 image index (3) 4 image index
(4) 9 image index (4) 9 image index
(5) Jump Display (5) Magnified view
Image Erase Protection Erase protection of one image at a time Erase protection of one image at a time
Image Erase Single image, All images on card, Checkmarked images, Unprotected images Single image, All images on card, Checkmarked images
Self Timer Approx. 2 or 10 sec. Approx. 2 or 10 sec.
Menu Categories (1) Shooting menu
(2) Playback menu
(3) Setup menu
(4) My Menu
(1) Shooting menu
(2) Playback menu
(3) Setup menu
(4) Custom Functions menu
(5) My Menu
Menu Languages English, German, French, Dutch, Danish, Portuguese, Finnish, Italian, Norwegian, Swedish, Spanish, Greek, Simplified Chinese, Japanese, Traditional Chinese, Korean, Russian, Polish, Hungarian, Czech English, German, French, Dutch, Danish, Portuguese, Finnish, Italian, Norwegian, Swedish, Spanish, Greek, Simplified Chinese, Japanese, Traditional Chinese, Korean, Russian, Polish
Firmware Update Update possible by the user. Update possible by the user.
Interface
Computer USB 2.0 Hi-Speed (Mini-B) USB 2.0 Hi-Speed (Mini-B, PTP)
Other Video output (PAL/ NTSC) Video output (PAL/ NTSC), Extension System Terminal
Memory Card
Type SD card, SDHC card CompactFlash Type I/ II (Microdrive compatible)1, External Media (with Wireless File Transmitter WFT-E3 only).
Supported Operating System
PC Macintosh Windows 2000 (SP4) / XP (SP2) / Vista (excl. Starter Edition) Windows 2000 (SP4) / XP (SP2) / Vista (excl. Starter Edition)
OS X v10.3-10.4 OS X v10.3-10.4
Software
Browsing & Printing ZoomBrowser EX / ImageBrowser ZoomBrowser EX / ImageBrowser
Other PhotoStitch, EOS Utility (inc. Remote Capture, Original Data Security Tools*) PhotoStitch, EOS Utility (inc. Remote Capture, WFT utility*, Original Data Security Tools*), Picture Style Editor
* Requires optional accessory * Requires optional accessory
Drivers PTP TWAIN Driver (Windows 2000) PTP TWAIN Driver (Windows 2000 )
Image Manipulation Digital Photo Professional (RAW Image Processing) Digital Photo Professional (RAW Image Processing)
Power Source
Batteries 1 x Rechargeable Li-ion Battery LP-E5 Rechargeable Li-ion Battery BP-511/BP-511A or BP-512/BP-514 (BP-511A battery supplied), 1xCR2016 for date & settings
Battery Life Approx. 500 (at 23°C, AE 50%, FE 50%)1
Approx. 400 (at 0°C, AE 50%, FE 50%)
Approx. 800 (at 23°C, AE 50%, FE 50%)1
Approx. 700 (at 0°C, AE 50%, FE 50%)
Battery Check Automatic Automatic
Power Saving Power turns off after 30sec or 1, 2, 4, 8 or 15mins. Power turns off after 1, 2, 4, 8, 15 or 30mins.
AC Power Supply Optional, AC Adapter Kit ACK-E5 Optional, Power adapter ACK-E2
Accessories
General Eyecup Ef, Eyepiece Extender EP-EX15II, Angle Finder C, Semi-Hard Case EH18-L Wireless File Transmitter WFT-E3, Original Data Security Kit OSK-E3, Eyecup Eb, E-series Dioptric Adjustment Lens with Rubber Frame Eb, Eyepiece Extender EP-EX15, Focusing Screens Ef (with Grid Ef-D, Super Precision Matte Ef-S), Angle Finder C, Semi-Hard case EH17-L
Lenses All EF and EF-S lenses All EF and EF-S lenses
Flash Canon Speedlites (220EX, 380EX, 420EX, 430EX, 550EX, 580EX, 580EX II, Macro-Ring-Lite MR-14EX, Macro Twin Lite MT-24EX, Speedlite Transmitter ST-E2) Canon Speedlites (220EX, 380EX, 420EX, 430EX, 550EX, 580EX, 580EX II, Macro-Ring-Lite MR-14EX, Macro Twin Lite MT-24EX, Speedlite Transmitter ST-E2)
Battery Grip BG-E5 BG-E2N, BG-E2
Remote Controller / Switch Remote Switch RS-60E3, Remote Controller RC-1/RC-5 Remote control with N3 type contact, Wireless Controller LC-5
Power Supply & Battery Chargers AC Adapter Kit ACK-E5, Battery charger LC-E5E, Car Battery charger CBC-E5, Battery Pack LP-E5 AC Adapter Kit ACK-E2, Compact power adapter CA-PS400, Battery charger CB-5L, Battery charger CG-570, Car Battery Cable Kit CB-570, Compact Power Adapter CA-570, Battery Pack BP-511A
Physical Specifications
Body Materials Stainless Steel/Plastic Magnesium Alloy body covers
Operating Environment 0 — 40 °C, 85% or less humidity 0 — 40 °C, 85% or less humidity
Dimensions 128.8 x 97.5 x 61.9 mm 145.5 x 107.8 x 73.5mm
Weight (body only) Approx. 475g Approx. 740g
1 with 50mm lens at infinity, -1 (1/m) dpt 1 with 50mm lens at infinity, -1 dpt
1 Large/Fine resolution 1 Large/Fine resolution
2 Based on Canon's testing conditions with 1GB memory card JPEG quality 8, ISO 100, Standard Picture Style. Varies depending on the subject, memory card brand and capacity, image recording quality, ISO speed, drive mode, Picture Style, Custom functions etc. 2 Depending on memory card speed / capacity
1 Based on the CIPA Standard and using the batteries and memory card format supplied with the camera, except where indicated 1 Memory card and battery door only
1 Compatible with large memory card capacities, including cards of 2GB and more
1 Based on the CIPA Standard and using the batteries and memory card format supplied with the camera, except where indicated