Pentax Optio S5Z

 

Manual Control Options
The Optio S5z is fundamentally an automatic camera. There is no way to directly set the aperture or shutter speed, let alone to set them both at once. By setting ISO and changing the EV setting, which changes the exposure, the user can influence aperture and shutter, as well as lighten and darken the image. Manual focus and white balance are also alterable.

FOCUS
Auto Focus (7.5)
The Optio S5z has a multi-zone autofocus sensor – it can check focus in many spots across the viewfinder. In its default mode, the camera uses focus points that are centered vertically in the frame. Once it’s ready, two green brackets appear over the spot that's in focus. There are two close-up modes: Macro, for distances from 7 to 20 inches; and Super Macro, for distances from 2.4 to 8 inches. The standard mode focuses from 16 inches to infinity.

In Focus Area mode, the user can select the area of the frame that the camera should get in focus. It's a very flexible system – there are 49 spots to choose from, and they cover the entire image.

The Optio S5z's autofocus tested well, delivering sharp focus in typical lighting; it's not unusual for a small camera with a very short focal-length lens to focus well – small cameras have huge depth of field even at their maximum aperture, which covers up minor focusing errors.

Manual Focus (3.0)
The Optio S5z has three manual focus modes. Infinity locks focus at infinity, for distant landscapes. Pan Focus locks focus at a medium distance, which may be a good compromise in situations where it's hard to get accurate focus. There is also an option to manually focus the image on the screen, using the four-way controller to rack focus in and out from infinity to about six inches. The center of the screen is magnified to aid focusing. While manual focus is often difficult using the LCD interface on compact cameras, the manual focus implementation on the S5z is better than many others; however, the image quality of the Optio S5z’s LCD in manual focus mode is not good enough to show the difference between "in focus" and "almost in focus." The problem is worst with the zoom at wide angle.
ISO (7.0)
The Optio S5z can be set to ISO 80, 100, 200, or 400, or it can be set to automatically choose a sensitivity rating. Certain scene modes will set the ISO, as will the Green Mode.

While 400 is a very common top ISO setting for small cameras, more and more compact cameras are beginning to offer 800 and 1600 ISO options; a helpful inclusion for night and indoor photography, given how ugly the harsh light from most fixed flash units can be. The Optio S5z shows much more image noise at ISO 400 than at 100, so Pentax's sensor and noise-suppression system clearly couldn't handle a higher ISO. However, it should be noted that the S5z utilized the common 80-400 range better than any compact camera we have tested thus far. Most cameras that offer 800 and 1600 ratings will still outperform the S5z, but its use of the typical range is impressive. If a more expansive sensitivity range is essential, take a look at the Fujifilm FinePix F10 for good low light performance and ISO flexibility.

For more information regarding the S5z’s handling of noise, check out the Testing / Performance sections of the review.

White Balance (7.0)
The Optio S5z has six preset white balance options: Daylight, Tungsten, Cloudy, Shade and two fluorescent settings, one for "daylight" tubes and one for "white" tubes. There is also a custom white balance setting, for situations that the presets cannot handle. To set the white balance manually, the user must bring up the white balance option, point the camera at something white, and press the shutter. The LCD shows a live display of the camera adjusting to the lighting, helping users determine the accuracy of the set color balance.

Exposure (7.0)
The Optio S5z's exposure modes are all automatic. In all of them except Green Mode, the EV control can adjust the exposure +/- 2 EV in 1/3-stop intervals. That's a standard range of control, though it's a bit unusual to have it available in so many picture modes.

Metering (7.0)
As with most compact digital cameras, the Optio S5z uses a multi-pattern metering system by default. Multi-pattern evaluates several segments of the view for exposure, and sets the exposure based on assumptions about typical pictures. For instance, it assumes that large, bright areas in the upper part of the frame are sky, and overexposes them to preserve detail in darker stuff at the center of the frame. Multi-pattern systems vary between manufacturers, but they are by far the most successful system for automated exposure.

The Optio S5z also offers an averaging mode, which measures exposure of the whole frame at once, with a bias for the center, and a spot mode, which measures a small area at the center of the frame. Both averaging and spot modes are useful to photographers who want to take a bit more control.

Shutter Speed (0.0)
According to Pentax, the Optio S5z’s purely automatic shutter operates from 4 to 1/2000 of a second; however, exposures longer than 1/4 of a second are only available in Night Mode. If you shut off the flash and try to take a picture in the dark in most modes, the camera stays at 1/4 of a second, no matter how badly that underexposes the picture. The F-stop and shutter speed display turn orange when the exposure won't make a good image, but the camera still goes ahead and takes them.

It seems that the Optio S5z is designed to protect the user from taking blurred pictures, but the result is no better - solid black pictures instead. A better choice would have been a warning message on the LCD, recommending a tripod or the flash.

Aperture (0.0)
The 5.8-17.4mm Pentax zoom lens has a maximum aperture that ranges from f/2.6 at the wide end to f/4.8 at the telephoto end. Pentax doesn't list minimum apertures, but in use, they seem to range from f/4.6 to f/7.7. That's pretty limiting, compared to the aperture ranges on film cameras, but smaller apertures aren't feasible with such small sensors.