Canon PowerShot S40 Review

Timings & File Sizes

The S40 is a nippy little operator, it doesn't keep you waiting, most operations are very quick. Indeed for major functions it's even faster than the G2, startup, switching between play / record modes are noticeably quicker. Other timings such as Auto Focus, Shutter Lag are identical to the G2.

Lens extension is faster and this makes a big difference to startup time (almost 2 seconds quicker). Another point which indicates that internal parts of the S40 are different to the G2 is its performance with the IBM Microdrive. The use of a Microdrive made less difference to startup and shutdown times but the S40's write times were longer (slower) than the G2 (although not by much).

Timing Notes: All times calculated as an average of three operations. Unless otherwise stated all timings were made on a 2272 x 1704 Super-Fine JPEG image (approx. 2.0 MB per image).

Power on tests were carried out with the lens cover 'almost fully open', there's a notch at the end of the covers travel, past this notch the camera powers up. Play power on test was carried out with the lens cover closed by simply sliding the 'PLAY lever' to the right.

The media used for these tests were:

• 16 MB Canon Type I CompactFlash card (as supplied)
• 320 MB Lexar Pro 12x Type I CompactFlash card
• 1 GB IBM Microdrive Type II CompactFlash card

Action	Details	Time, seconds (Canon CF)	Time, seconds (Lexar 12x CF)	Time, seconds (Microdrive)
Power: Off to Record	Lens extension	4.1	4.4	4.1
Power: Off to Play *1	Image displayed	2.2	1.8	4.8
Power: Record to Off	Lens extended	1.9	1.9	2.0
Power: Play to Off *1	Lens retracted	<0.5	<0.5	~0.7
Mode: Record to Play	Image displayed	2.0	2.1	2.4
Mode: Play to Record	Lens extended	1.7	1.6	1.6
Play: Magnify		0.5	0.5	0.8
Rec: Thumbnail view		1.1	1.1	1.9

Action	Details	Time, seconds
Zoom from Wide to Tele	Full zoom from 35 mm to 105 mm (3 x)	2.0
Auto Focus LAG	Half zoom, Normal AF *3	0.9 - 1.0
Auto Focus LAG	Half zoom, Macro AF *3	1.1 - 3.0
Shutter Release LAG	Using viewfinder	<0.1
Shutter Release LAG	Using LCD monitor	0.1
Total LAG	*3	~1.0
Off to Shot Taken	Using supplied 16 MB Canon CF card	5.5
Shot to Shot	Same for LCD in review or preview modes (AF)	2.2

Auto Focus LAG is (roughly) the amount of time it takes the camera to autofocus (a half-press and hold of the shutter release button), this timing is normally the most variable as its affected by the subject matter, current focus position, still or moving subject etc. This timing is an average.

Shutter Release LAG is the amount of time it takes to take the shot after autofocus, this timing assumes you have already focused (half-pressed the shutter release) and now press the shutter release button all the way down to take the shot. This timing is an average.

Total LAG is the total time it takes (not just the two above added together) if you haven't pre-focused, that is no finger touching the shutter release button, press it all the way down in one movement, this new timing is how long it'd take if you were in one of those spur-of-the-moment situations. This timing is an average.

Continuous modes

The S40 features the same new 'High Speed' continuous shooting mode we saw on the G2 as well as normal continuous. The manual states normal continuous mode as 1.5 fps and high speed continuous as 2.8 fps. Our results show that this depends on the selected image size / quality.

The table below shows the results of our continuous shooting test, indicating the actual frame rate along with maximum number of frames and how long you would have to wait after taking the maximum number of frames before you could take another shot. Timings taken using a 320 MB Lexar Pro 12x Type I CompactFlash card.

It's clear that the reported 1.5 fps is a little optimistic, having said that the high speed continuous is closer to the reported figure. These results are also far less consistent than we got from the G2, I'm not sure why that is.

Continuous mode Flush Timing

The timings above represent the speed of the camera and its internal buffer, however the speed of the Compact Flash card will also have an impact on shooting continuously, it defines how long we must wait before the "burst" of frames are written away to the card (flushed). The flush process happens in the background, you can still take a shot as long as there is space in the internal buffer.

These results are interesting, although the Lexar and IBM Microdrive are both faster than the supplied CF card the difference is not as significant as we observed with the G2. This is probably down to a higher performance CF interface in the G2.

File Flush / Display Timing

Timings shown below are the time taken for the camera to process and "flush" the image out to the Compact Flash card, the timer was started as soon as the shutter release was pressed (shutter click was heard) and stopped when activity indicator LED beside the viewfinder stopped blinking. This means the timings also include the cameras processing time and as such are more representative of the actual time to "complete the task".

The media used for these tests were:

• 16 MB Canon Type I CompactFlash card (as supplied)
• 320 MB Lexar Pro 12x Type I CompactFlash card
• 1 GB IBM Microdrive Type II CompactFlash card

Once more the difference between the different media types is noticeable but there's less of a difference than we measured on the G2. Overall the Microdrive still offers the best $/MB even considering its slightly slower performance.

File Sizes

Here's a comparison of the average byte size of each of different image size / quality combinations.

Battery life

We ran the camera through our new battery life test. This test is designed to be fair and comparative to each camera and battery type:

• Take 4 shots without flash
• Wait 2 minutes (50% of the time powering the camera off)
• Take 1 shot with flash
• Wait 1 minute
• Repeat

This test routine was carried out on five different cameras simultaneously. All batteries had been fully discharged and recharged before the test and all cameras were reset to their factory default settings. Here are the results:

With just under half the battery power of the G2 the S40 managed to last a respectable two hours and thirteen minutes, what's also clear as the results in this table build is that Lithuim-Ion batteries last significantly longer than NiMH batteries of equivalent power.