An
optical zoom camera can be zoomed to its optical limit, and further zooming is sometimes allowed by digital zoom. Digital zoom uses the centre area of the optical image to enlarge the image. By reducing the image size, digital zoom occurs without image deterioration of the output image, and some cameras have a "not-deteriorated image" mode or an image deterioration indicator. The table below shows the not-deteriorated zoom limit for some
megapixel (MP) image sizes of a particular camera with optical zoom 24x, and digital zoom 4x for its maximum capability: File:Zoom10x.JPG|Handheld. Zoom 10×, Optical zoom 10×, 2 MP from 16 MP maximum, ISO 800, 1/420, F/14.0, image is clear File:Zoom28x.JPG|Handheld. Zoom 28×, Optical zoom 10×, and Digital zoom 2.8×, 2 MP from 16 MP maximum, ISO 800, 1/420, F/14.0, initial of deteriorated digital zoom, image is still clear File:Zoom40x.JPG|Handheld. Zoom 40×, Optical zoom 10×, and Digital zoom 4.0×, 2 MP from 16 MP maximum, ISO 800, 1/500, F/14.0, image is still clear with some noise. Magnification in deteriorated digital zoom zone is 40× : 28 = 1.4× File:Zoom72x.JPG|Handheld. Zoom 72×, Optical zoom 10×, and Digital zoom 7.2×, 2 MP from 16 MP maximum, ISO 800, 1/640, F/14.0, more noise, but the detail is still clear. Magnification in deteriorated digital zoom zone is 72× : 28 = 2.6× File:Zoom72xFullResolutionResize.JPG|Handheld. Zoom 72×, Optical zoom 10× and Digital zoom 7.2× taken in full resolution 16 MP, but resize to 2 MP for uploading, ISO 800, 1/680, F/14.0, more noise, but the detail is more clear. Magnification in deteriorated digital zoom zone is 72×: 10 = 7.2×, the bigger the number, the worse the image Some camera
firmwares store lossily digitally zoomed images with accordingly reduced dimensions (width and height) rather than upscaling it to the original
raster resolution. The benefits are reduced file sizes and the ability to calculate the zoom level from the image's dimensions, if not included in its
metadata. Cameras may have an intelligent zoom feature that allows an additional magnification of 2.0× on top of its optical zoom. Many cameras have 2 options: 1.4× and 2.0×. The intelligent zoom only uses the centre of the
image sensor and does not interpolate the original resolution, so the resulting image quality is good in reduced resolution. Smartphones with optical zoom have lenses with 3× or 5× magnification. Trying to zoom in further than this limit may result in loss of quality as the camera switches to digital zoom, though hybrid zoom may mitigate this. Many cameras, including
mobile phone cameras, also employ lossless digital zoom for video recording by using the spare resolution of the image sensor for cropping by taking advantage of used video frame resolutions often being significantly below the available resolution of the image sensors. and "Intelligent Zoom" (
Panasonic and others). There are also cameras with digital zoom functions as high as 7.2× and Smart Zoom with approximately 30× total zoom (optical zoom 20× and digital zoom 1.5×) for 7MP from 16MP total resolution, and also 144× total zoom (optical zoom 20× and digital zoom 7.2×) for VGA 640x480. ==Aesthetic==