At 4.8 ounces and only 0.8 inch thick, the Z70's slim, metal body is the right size to fit into your pocket. Though the size is right, you should still be very careful when pocketing this camera. Besides the tiny power button on the top, the two flat record and playback buttons on the camera's backside can also turn it on. If your pocket is too tight or if you don't pay attention, you could drain the camera's battery or have the lens pop out at inopportune times.
The Z70 comes with the same handy features standard on all of Casio's Exilim cameras. Digital-image stabilization helps reduce shake and blur when using the camera's 38-to-114mm-equivalent lens. However, that feature shouldn't be confused with the more-effective optical or mechanical-image stabilization offered by some other camera makers. Casio's Best Shot modes offer users more than two dozen scene presets, including the auction-photo-optimizing eBay mode. Unfortunately, the camera can reach only ISO 400 for low-light and high-speed shooting. It also lacks an optical viewfinder, forcing users to frame shots and review images on the camera's grainy and washed-out 2.5-inch LCD screen.
Despite a few quirks, the Z70's performance is excellent. The camera powers up in only 1.2 seconds and can take a shot every 1.3 seconds. With the onboard flash enabled, shot-to-shot time increases to 2.5 seconds. Shutter lag measures a speedy 0.4 second in bright light and only 1 second in dim light. Burst mode was acceptable, pumping out 27 full-resolution images in 33 seconds for a rate of 0.8 frame per second.
A Quick Shot mode lets you can snap off shots even more rapidly by forgoing focusing, but when you get home to edit, e-mail, or print them, they'll be nothing but grainy blurs. Press the shutter release down halfway until it achieves a focus lock; then take the shot. It takes a bit of getting used to, but once you have the rhythm down you'll be taking quick, focused photos.
The Z70 handles exposure and color very well, but its images are otherwise disappointing. Fine details appear soft even in very good circumstances, and noticeable processing artifacts and image noise further obscure the picture. We also notice some distinct lens distortion at both the wide-angle and telephoto ends of the camera's zoom.
Though its slim size and price tag make it quite appealing, the Casio Exilim EX-Z70 has a few notable quirks to overcome. If you don't mind getting used to shooting in a certain rhythm or gingerly carrying the camera in your pocket, the Z70 could be a nice, responsive choice. Instead of the Z70, you might consider the superior ultracompact Canon PowerShot SD600. It has only 6 megapixels and is a bit thicker than the Z70, but its image quality is far superior.