Canon PowerShot SX150: Performance

PERFORMANCE
The SX150 IS doesn't seem awfully fast when compared to its closest competitors, but numbers don't always tell the whole story. The SX150 IS performs credibly and is easily competitive with any camera in its street price range. When you design a camera with a 12x zoom some operational speed must be sacrificed (particularly at longer focal length settings) because a very long lens will obviously move and focus more slowly than a substantially shorter lens.

Shooting Performance
Performance and image quality should be the primary considerations when assessing digital camera performance. The SX150 IS comes in near the top when compared to its competition in terms of timing, except for its slower than average AF acquisition times.

Shutter Lag (press-to-capture, pre-focused)

AF Acquisition (press-to-capture, no pre-focus)

Continuous Shooting

*Note: Continuous shooting framerates are based on the camera's fastest full-resolution JPEG continuous shooting mode, using the fastest media type available (300x CF, SDHC, etc.). "Frames" notes the number of captures recorded per burst before the camera stops/slows to clear the buffer.

While the 0.53 second AF Acquisition (press-to-capture with no pre-focus) time noted in the DCR test chart looks pretty slow when compared to the Panasonic Lumix DMC-FZ150, that 1/3 of second difference isn't really significant in the real world and it can be attributed, at least in part, to the included Panasonic LR6 Alkaline AA's. I suspect performance will improve noticeably when using 2500 mAh NiMH rechargeable AAs.

The SX150 is fast enough to function nicely as a general purpose digicam and quick enough to capture the decisive moment - in all but the most extreme shooting situations. The SX150 IS powers up promptly and shutter lag shouldn't present much of a problem. Shot-to-shot times are between 2 and 3 seconds with OTC Alkaline AAs.

Lens Performance
When the SX150 is powered up - the lens automatically extends from the camera body and when the camera is powered down, the zoom retracts into the camera body and a built in iris-style lens cover closes to protect the front element. The SX150 IS's f/3.4-5.6 5.0-60.0mm (28-336mm equivalent) zoom makes this digicam ideal for a broad variety of photographic applications - including shooting group pictures in tight indoor venues, capturing expansive landscapes, snapping excellent travel pictures, nailing not too distant wildlife, shooting youth sports like a pro, and getting in-your-face macro shots of bugs and flowers.

The SX150's zoom is impressively compact and it doesn't appear to be flimsy, but it is (unavoidably) an extremely complex lens and as complexity increases optical faults are magnified exponentially. Corners are noticeably soft at the wide angle end of the zoom, but they are appreciably sharper at the telephoto end of the range. The SX150 IS's f/3.4 maximum aperture (at the wide end of the zoom) is about a half a stop slower than the f/2.8 maximum apertures of many upper tier point-and-shoots, but it is fast enough for almost anything this camera's target audience is likely to shoot outdoors.

Zoom operation is fast, smooth, and fairly quiet, but this lens exhibits noticeable barrel distortion (straight lines bow out from the center) at the wide-angle end of the zoom and visible pincushion distortion (straight lines bow in toward the center of the frame) at the telephoto end of the zoom range. Chromatic aberration (purple fringing) is present, especially in high contrast color transition areas, but managed nicely. Overall, the SX150's 12x zoom is surprisingly good.

This PowerShot's optical image stabilization system reduces blur by quickly and precisely shifting a lens element in the zoom to compensate for involuntary camera movement. Typically, IS systems allow users to shoot at shutter speeds up to three EV (exposure values) slower than would have been possible without Image stabilization. Keeping a lens with a focal length range from ultra-wide to super-telephoto steady (without a tripod) poses some impressive challenges.

Canon has equipped the SX150 IS with what they claim is the most advanced and effective optical Image Stabilization system ever used in a P&S camera (it assesses camera shake about 8,000 times per second) providing up to 4.5 EV of compensation. The SX150 IS's 4.5-stop optical Image Stabilizer incorporates Canon's Intelligent IS technology that detects the shooting situation and automatically applies the most appropriate image stabilization settings from seven possible options.

For example, Panning IS is enabled when users follow the action horizontally, ensuring the IS system stabilizes in only one direction, while Macro IS (with Hybrid IS technology) is meant for shooting sharp handheld close-ups. Powered IS uses Canon camcorder technology to make it easy to film distant subjects with the long zoom, and Tripod mode switches off the Image Stabilizer when the camera is placed on a stable surface or mounted on a tripod.

The SX150 IS features the same TTL Contrast Detection 10-point AiAF system, providing three AF modes: Face AF, Tracking AF, and Center AF as Canon's popular SX230 HS. In all exposure modes, the camera analyzes the scene in front of the lens and then calculates camera-to-subject distance to determine which AF point is closest to the primary subject (closest subject priority) and then locks focus on that AF point.

The SX150 IS's face detection AF mode is linked to the camera's exposure and WB systems so the camera automatically finds, locks focus on, tracks and then optimizes exposure for up to nine faces - or shooters can lock on a single face and track it through the crowd. The SX150 IS's Center AF mode is a good choice for traditional landscapes and informal portraits and an even better option for street shooting, because serious photographers don't want the camera deciding which face in the crowd to focus on. AF is a bit slower than average, but dependably accurate.

There is a dark cloud on the SX150's horizon that potential purchasers should consider. The SX150 is a complex, feature rich, digicam with a long zoom - so it is (not unexpectedly) a profligate power user. I do a lot of shoot, review, delete, and re-shoot so my battery use is probably a bit heavier than that of most P&S digicam users, but the included AA batteries (a pair of Panasonic LR6 Alkaline AA's were packed with my test unit) only lasted long enough for the DCR test lab to run its standard array of tests and for one fairly short shooting session for me. A pair of cheap OTC Eveready "Gold" Alkalines purchased when the included batteries failed on me in the field got me through the rest of the afternoon and two longer shooting sessions and three short video clips before they bit the dust.

I bought a four pack of Energizer MAX Alkaline AA's (the World's first zero mercury AA alkalines for environmentally conscious shooters) to replace the Eveready "Gold" alkalines. I promised in my SX150 preview to discuss their performance in the full review - the Energizer "MAX" alkalines (even though they cost twice as much) only did marginally better than the cheap Eveready "Gold" alkalines.

Canon claims the SX150 IS is good for about 320 exposures with a pair of Canon NB-3AH (2500 mAh) NiMH rechargeables - I couldn't find any numbers for OTC Alkaline AAs, but I'm guessing (based on my experiences with the camera) that it is less than 100 exposures. Most shooters should opt for re-chargeable NiMHs or more expensive Lithium AA's because OTC alkaline AA's will be too expensive long-term as a power source and should only be used as a last resort or when traveling.

The SX150 IS's multi-mode pop-up flash provides an acceptable selection of artificial lighting options, including Auto, Flash On, Flash Off, Slow Sync, and Red-eye reduction plus menu options including flash exposure compensation at +/- 2 EV in 1/3 EV increments. According to Canon, the maximum flash range is a bit more than 18 feet, which seems a little optimistic given the small size of the flash. Based on my very limited flash use, the flash recycle time is between 4 and 5 seconds with OTC Alkaline AA's.

The Canon PowerShot SX150 supports SD, SDHC, and the SDXC format memory cards, but provides no internal memory. The SX150 IS also provides Eye-Fi Card support.