Top of camera controls

Top of camera controls are limited to the power button, shutter release and zoom lever. The power button requires a 0.8 second hold before it will power off, this guards against accidental power ups, power off is instant. The size differential between the power button and shutter release means that there shouldn't be too many accidental power-off's.

Zoom controller (shooting mode)

	Zoom Wide Zooms towards full wide angle (36 mm). There are seven zoom steps including full wide angle and telephoto.
	Zoom Tele Zooms towards full telephoto (108 mm), if you pass the 108 mm mark the camera will begin to digitally zoom (indicated by a blue text display). There is a menu option to disable digital zoom.

Zoom controller (play mode)

	Toggle Thumbnail view (wide button) Toggles between display of a single full screen image, 3 x 3 thumbnails on the LCD screen or 3 x 3 thumbnails which can be browsed a page at a time. Push again to enter a 9 image page by page 'jump mode'.
	Playback Magnify (tele button) Press to magnify the image, hold to magnify up to 10x. Use the 4-way direction controller to scroll around the image. Magnifying is very fast, if you hold the zoom controller in the tele position you can be at 10x zoom in around one second.

Rear of camera controls

As noted earlier in this review the rear of the S400 is fairly similar to the S230, the main differences are the shooting mode dial at the top left and the re-labelling of the FUNC button. I personally found the mode dial a little awkward to use, it has to be stiff to avoid accidental movement but its small size means that it can at first seem very unfriendly.

Shooting mode dial

	Auto record mode This is really the "point and shoot" mode, while you still have the option to choose resolution, JPEG quality and flash mode you can only select between self-timer and single shot drive modes, macro or normal focus mode, you can't change white balance (which is set at Auto) or set an exposure compensation.
	Manual record mode Manual record mode operates virtually identically to auto record mode except that you now have control over settings such as white balance, exposure compensation, spot metering, AF points, picture effects etc.
	Stitch Assist Designed to make shooting of panorama / stitch shots easier. You have a choice of two different stitch modes: left-right or right-left. The display changes to show previously shot frames in the sequence to help alignment of each frame. Exposure and White Balance are locked to the first frame.
	Movie Mode Shoot short movie clips (AVI format) at a variety of resolutions (all with mono audio @ 11.24 KHz): • 320 x 240, 15 fps, max 3 minutes (including audio) • 160 x 120, 15 fps, max 3 minutes (including audio) (3 minute recording requires a high speed CF card)

Camera mode switch

	Play mode Switches immediately to play mode, displays the last image taken / last image on the Compact Flash card. The lens does not immediately retract if it's already extended, it will do so after 60 seconds in play mode.
	Record (shooting) mode Immediately switches to shooting mode, lens extends (if it is not already) zoom resets to the last used position and camera prepares to shoot (depending on exposure mode - below).

Button controls

	Metering mode • Evaluative • Center weighted average • Spot	AE-Lock / FE-Lock With the shutter release half-pressed press this button to lock Exposure; AEL (if flash is enabled this will lock flash exposure; FEL). AE/FE lock is active until you press this button again (even for multiple shots).
	Focus modes • Normal focus range • Macro focus range • Landscape (Infinity focus)	AF-Lock With the shutter release half-pressed press this button to lock Auto Focus, AFL is displayed on the monitor. AF lock is active until you press this button again (even for multiple shots).
	Flash mode • Auto Flash • Anti-Redeye • Fill-in Flash (forced on) • Inhibit Flash (forced off) • Slow-sync Flash
	Drive mode • Single shot • Burst shots (continuous) • Self-timer (2 or 10 secs)
SET	No Action (Used to confirm menu settings)
MENU	Enter / Leave Record Menu The record menu is detailed later.
DISP	LCD monitor / preview display mode • Simple mode (just AF points) • Detailed mode (AF points, all camera settings) • LCD monitor off
FUNC	Function menu The FUNC button displays an overlaid menu which provides access to several photographic settings. In Auto exposure mode you can only modify the Image Size / Quality, the remaining settings are available in Manual mode. Settings appear in a column down the left side of the display, use the arrow keys to move up and down each option and the roll the command dial or press left / right arrow keys to change. The icons used below to represent each setting are the default for that setting and that the icon will change once a setting change is made. Exp. compen. +/-2 EV in 0.3 EV steps White balance Auto, Sunny, Cloudy, Incandescent, Fluorescent, Fluorescent High, Manual Sensitivity Auto, ISO 50, ISO 100, ISO 200, ISO 400 Photo Effect Off, Vivid, Neutral, Low Sharpening, Sepia, B&W Image quality Super Fine, Fine, Normal Image size 2272 x 1704, 1600 x 1200, 1024 x 768, 640 x 480

Based on the DiGiC platform and inheriting the level of manual control first seen on the S330 the S400 provides a good range of options for the photographer. A surprise to some will be the availability of AE-lock, FE-lock and AF-lock.

Control functions in play mode

SET	Setting / Menu confirm Used to confirm changed camera settings or options in the camera menus.
MENU	Enter / Leave the Play Menu Pressing this button in record or play mode enters that mode's settings menu (described in detail on the next pages of this review).
DISP	Display Mode Toggles between three LCD display modes: Image only display, Image and brief frame information, Image and detailed exposure information.
	Erase image Erases the image, requires confirmation: Erase / Cancel.

Orientation sensor

The S400's orientation sensor indicates the current orientation of the camera with a small icon in the top right of the LCD display (), the arrow above the camera always pointing the upward direction. The camera recognizes left down portrait (counter clockwise), normal landscape (0°) and right down portrait (clockwise). The sensor changes orientation anywhere past the 45° point in either direction.

This orientation is then stored in the header of the image file (EXIF if JPEG), the camera will display images in the correct orientation during playback and in the supplied Canon software. Some third party applications are now starting to recognize the EXIF orientation tag, notably ACDSee 5.0 which has an 'Auto' option in its lossless rotation dialog, simply select all JPEG images in a folder, choose 'Auto' rotate and the software will losslessly rotate those images which need rotation.