>> I've heard quotes that your eyes are about 6 megapixels >> in quality >> (for a good-sighted person that is). Your eyes are >> hierarchic though - >> you have fairly low quality on the sides and high-quality >> on the small >> area you're looking at directly. Since the screen(s) >> can't predict >> where you're looking at, you have to have a pretty high >> overall >> quality to show all details. Eye/brain system is immensely more capable in the centre. My feeling is that somewhere around 5 MP a modern digital image gets good enough that more MP are nice but not essential. BUT see below re other factors. This is not just because that's what i happen to have (also see below). Bearing in mind that a doubling of MP when applied to a given area only increases the linear pixel/length by sqrt(2) = +40%. That hardly sounds useful. BUT there's no doubt that a 5 MP image is far more useful visually than a 2 MP one. I have a 2 x 6MP and 1 x 8MP cameras and had a 5 MP one that died. All these make good use of the sensors using appropriate lenses. The 6 MP images are vastly superior to the 5MP or 8 MP because the sensor is about 8 times larger (APSC DSLR) and signal to noise becomes the overwhelming quality factor. Note that the current market driven rush to make cameras with tiny sensors and 4/5/6/7/8/10 MP is a formula for disaster. Akin to 18V batteries in bottom end power tools. My 8MP and 5MP were models in the same range (KM A2 and 7Hi) use the same sensor area and the 8 MP is substantially *inferior* WRT the 5 MP. I'd prefer another 5MP KM 7Hi quality wise to the A2. I can actually assess a relative ISO and noise performance by taking photos at various ISO settings and comparing visual quality, and it's different by a factor of about 8:5. ie by the pixel area. The 5MP camera had a 100 ISO minimum "film" speed. The 8 MP camera has a 64 ISO setting and needs it! SO it's not just that the eye has a given equivalent MP rating but that the signal to noise ratio and other factors are also at a certain level. Also, dynamic range is a vital factor. Modern digital cameras with single sensor cells per pixel do not have the dynamic range of the eye. Cameras with two sensors of large and small area (usually) and varying effective sensitivity come closer. Fuji has been doing this for some years and, while their images are not considered top of the range overall, they have been considered superior for eg wedding photography where dynamic range is paramount. [The lady tends to dress in white with super fine detail and the guy in black. Then they stand in a church with a beam of sunlight across the altar area and deep shadows behind. People want ALL of this to look OK on the photos.] 16 bits of dynamic range is not too much, whereas cameras with 8, 10 and 12 bits are more normal. Russell -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist