ast range of standard and specialist lenses. The disadvantage (for a digital SLR) is that the mirror only swings out of the way when the shutter is pressed, which means that the image does not reach the sensor until the moment of exposure. Only then does the camera have a chance to do autocorrection on the image. Compact cameras, also sometimes described as lens shutter cameras, don't offer the optical choice or quality of an SLR camera but the fact that the sensor array itself is looking at the image before the shutter is depressed helps to improve the metering process. In other words, the image that comes out of a compact camera can actually look better than the image coming out of a digital SLR. The digital SLR demands more knowledge and skill from the user and may require more postediting to get the required colour and light balance effects. In addition to the cost of the optics, a high-end SLR or compact digital camera also requires a substantial amount of storage bandwidth. To preserve image quality, images are either saved as raw data or as a TIFF (tagged image file format). A TIFF file uses lossless compression. The original image can be recreated after compression without losing any of the original source information. Even a TIFF of an 8-megapixel image still produces a 20-Mb file. This takes 30 seconds to save on to a compact flash card. High-end cameras get round this problem by having buffer memory - typically enough to support ten or twelve seconds of 'fast shooting' at say 2 frames per second. Midtier compact cameras still have good-quality optics - not perhaps as good as a high-end SLR but still good enough for most print applications, at least up to A4 size. If pictures are just being taken to put on the web, then a GIF image (graphic interchange format) is used. Midtier and (most) entry-level digital cameras are therefore more than adequate for 'display online' applications. 8.3.6 The Effect on Camera Phone User Expectations The rapid increase in digital camera quality over the past ten years and