The overall performance of the CX series has been steadily improving with each new model, but for some reason the CX4 is slower in some respects than its predecessor. It starts up and is ready to shoot in approximately 2.7 seconds, which is pretty respectable, but actually slightly slower than the CX3. Likewise the shot-to-shot time in single shot mode is approximately 1.8 seconds, again very fast by current standards but slower than the CX3. The CX3's outstanding continuous shooting performance is unchanged however, with the CX4 capable of shooting 15 shots at 5fps at full 10 megapixel resolution, 26 frames at 30fps and 2MP resolution, or 120 frames at 60fps or 120fps and 640 x 480 resolution.
The nine-point AF system is unchanged since the CX2, and is still very fast and accurate with excellent low light performance. The CX4 has a good AF assist lamp with a range of approximately three metres. The flash is the same as the CX3, a good powerful unit with a range of around four metres and a recharge time of just under five seconds, which is faster than average. The CX4 is powered by the same 950mAh li-ion cell and the CX3, and the charge duration seem to be the same too, in other words well over 300 shots.
I really hope that Ricoh makes some significant improvement to image quality for the next upgrade of the CX series, because to be honest the CX4 looks a bit shabby compared to most of its similarly-priced rivals. The exposure system is very inconsistent, varying the exposure by as much as half a stop between consecutive shots of an identical subject. The lens quality could also do with a little attention; its overall sharpness could be a bit better, and while it avoids barrel distortion and corner blurring it does suffer from significant chromatic aberration at the edges of the frame.
One change for the better between the CX3 and CX4 is the ISO noise control. The CX4 has lost the 80 ISO lower setting, but seems to have benefited, with significantly better image quality at 400 ISO, and usable results at 1600 ISO. Even the 3200 ISO maximum setting is better than some recent rivals, although you wouldn't want to use it for every shot.
All in all the CX4 is certainly a net improvement over the already impressive CX3, but considering its high price the CX series is now lagging behind recent rivals such as the Casio FH100, Panasonic TZ10 and Samsung WB650. It's in some danger of being left behind in a fast-moving market. Rather than adding a few bells and whistles Ricoh should be looking at a thorough re-design and a new lens for its next model.
The CX4 continues Ricoh's tradition of well-made, technically advanced high-performance long-zoom cameras, and introduces a couple of useful new features to an already impressive list. Performance and results are good, however the ageing body design is looking a bit stale, and the inconsistent exposure metering and less-than-perfect lens are disadvantages.