The H15's overall performance is a little on the slow side. It starts up and is ready to shoot in less than three seconds, and shuts down again in about two and a half, which is about average for the class, but the shot-to-shot time in auto mode is approximately 2.8 seconds, which is a little slower than the performance of the H10. In Premium Auto mode it is slightly slower thanks to the extra processing involved, at approximately three seconds.
If the shooting speed is a bit slow at least the autofocus system is nice and fast even at maximum zoom. It works well in dim light too, focusing quickly even in darkness thanks to a bright green AF assist lamp. Flash range is adequate at around three and a half metres, with good frame coverage even at extreme wide angle.
The EX-H10 had better than average image quality, but unfortunately the same cannot be said for the H15. The lens quality is still very good, with excellent centre sharpness, virtually no barrel distortion despite its 24mm wide angle, and good corner sharpness with almost no chromatic aberration. However the Premium Auto mode over-processes the image, ironically reducing the overall level of detail.
The increase in sensor resolution has not helped either. Image noise is more noticeable than for the H10, and the more intense noise reduction causes a reduction in detail from 400 ISO upwards. The maximum ISO setting is 3200, but at this speed the image quality is very poor.
The Casio Exilim EX-H15 is a well-made and sensibly designed camera with a useful range of features and a comprehensive and easy-to-use menu system. Performance is quite slow however, and image quality is not as good as the previous EX-H10 model.