Pentax continues its journey through the alphabet with the Optio S5z, which replaces the popular Optio S5n, in turn a replacement for the S5i. Once again, the principle change is an increase in the size of the LCD, which has grown from 46mm (1.8 inch) on the S5i to 51mm (2.0 inch) on the S5n to a camera-dominating 64mm (2.5 inch) on the S5z. This is surely the end of the line, though: not only does the 'z' appellation leave little room for further upgrades, but also it's hard to see how it would be physically possible to put an even larger screen on this small camera.
Other changes include the replacement of the Optio S5n's docking station with a simple battery charger and a new Comment space function that leaves a blank strip along the bottom of your photo, so you can add handwritten notes.
Measuring 83 by 55 by 22mm, the Optio S5z is 3mm taller than the S5n, but it's still just possible to hide it behind a credit card. With battery and SD memory card in place, the S5z weighs 124g. Note that Pentax doesn't include a memory card with the camera, so you should budget for purchasing at least a 128MB SD card. If you want to record movies, get a fast 512MB or 1GB card.
The 64mm LCD takes up most of the back, leaving only a narrow strip on the right-hand side for the other controls. Consequently, all the buttons are small, with the smallest one measuring just 2.5mm across. That said, we like the use of four separate direction buttons around the central OK button, rather than a five-way rocker switch. There's only one place where you can rest your thumb, about one third of the way down the right-hand side, and all Pentax provides by way of a grip is five tiny rubber dots. The aluminium alloy front is stylish but slippery, so you'll want to use the supplied wrist strap at all times -- otherwise you'll risk dropping the camera.
The big LCD is bright and contrasty, making it usable even outdoors, although in bright sunshine we sometimes wished for an optical viewfinder. Although the LCD is significantly bigger than the one on the S5n, the resolution is unchanged, so you don't see any more detail -- you just get a bigger picture.
We were disappointed that the S5n's docking station has been replaced by a simple battery charger. The new arrangement is better for travellers, because there's less to carry, but it isn't as convenient for day-to-day use. With the S5n, you just dropped the camera into the stand to recharge the battery; now you have to take the battery out, put in the charger and then remember to put it back in the camera before you go out.
We were pleased to see that Pentax has retained the neat sliding doors that protect the USB and DC-in ports. They look good, aren't as fiddly as rubber port covers and seem unlikely to break or get lost.
The Optio S5z has the same 3x optical zoom, 36-to-107mm (35mm equivalent) lens as the S5n. A wider wide-angle setting would be useful for photographing interiors and groups of people, but the range is about normal for an ultracompact. In macro mode, the closest focusing distance is 180mm; Super-macro mode reduces this to 60mm.
The camera powers up in capture mode. Press the OK button to cycle the LCD through four different display options: basic settings, detailed settings including a (small) live histogram, rule-of-thirds framing guide, and no settings. The autofocus area is marked in all four displays and when you half-depress the shutter button to focus the lens, the display shows the selected focus point, the shutter speed and the aperture. The default option for the autofocus is a wide area spanning the centre of the image, containing three separate focus points, but you can set it to use only the central focus point if you prefer.
The direction buttons provide easy access to flash, self-timer and focus settings. You get several options in each category and you might need to venture into the manual to decipher some of the icons. Focus options include manual, which we found almost impossibly difficult, and the more useful focusing area, which lets you move the 'must be in focus point' to one of 49 possible areas spread equally around the frame. White balance, metering mode and exposure compensation are set via the menu, although you can customise the camera so you can access them by pressing the Quick button, followed by a direction button.
If you need assistance with your photography, press the Mode button to bring up a palette of scene modes. These include Landscape, Flower, Portrait, Self-Portrait, Sunset, Food, Pet, Text, Sports and Surf & Snow. There's also a Movie mode, a Panorama Assist mode that helps you take sequences of images that you can stitch together on your computer, and a Special Effects mode. The last gives you a choice of three effects -- Posterisation, Soft and Slim -- or the new Comment Space option, which lets you leave a blank strip along the bottom of the image. The strip can be either one quarter or one eighth of the height of the image, and can be applied in landscape or portrait mode. The theory is that when you print the image, you can write notes or comments in the blank area. We can't think why you'd want to sacrifice one quarter of your image merely so you can scribble something at the bottom at a later date, but maybe this feature will appeal to obsessive annotators.
The Movie mode records 640x480-pixel video at 30fps, with mono sound, to the capacity of your memory card. The S5z also offers basic editing functions, enabling you to cut a movie into two separate files, or stitch two movies together.
Snapshots were generally bright and sharp, although sometimes the camera had difficulty choosing the correct focus point. Using the default setting, the autofocus has three focus points to choose among, and it should select the one which is closest to the camera. On occasion it struggled to make a choice or selected the wrong point. It also had a slight tendency to overexpose -- a trait we didn't notice in the S5n. On the plus side, the S5z made a valiant effort to retain shadow detail in strongly backlit scenes.
Like the S5n, the S5z struggled to hold detail in intense reds, and skin tones were very slightly pink -- although not unflatteringly so. Otherwise colours were bright, clean and accurate. The Super-macro mode works well for close-ups of flowers and other small objects.
The built-in flash has a range of 3.5m with the lens at its widest setting and 2m at the telephoto end. While it won't light up a ballroom, it's more powerful than the flashes on most ultracompacts. It's certainly adequate for snapping your friends in restaurants or at parties.
Movies were impressive, with smooth motion and good detail and colour. The S5z is no substitute for a camcorder, but you can have fun shooting short clips.
Overall, we doubt you'll find much to complain about, although setting the exposure compensation to dial down the exposure slightly may improve your photographs.
Additional editing by Nick Hide