Digital zoom is a method of decreasing the apparent angle of view of a digital photographic or video image. It is accomplished electronically, with no adjustment of the cameras optics, in the former case, digital zoom tends to be superior to enlargement in post-processing, because the camera may apply its interpolation before detail is lost to compression. In the latter case, resizing in post-production yields results equal or superior to digital zoom, modest camera phones use only digital zoom and have no optical zoom at all. Usually cameras have an optical lens, but apply digital zoom automatically once its longest optical focal length has been reached. Professional cameras generally do not feature digital zoom, Digital zoom use the center area of the optical image to enlarge the image. By reducing the MP image size, using digital zoom can be done without image deterioration and some cameras has Undeteriorated image mode or at least has Image deterioration indicator. The table below give Undeteriorated zoom limit for some MP image size of a camera with Optical zoom 24x and Digital zoom 4x for its maximum capability, Note. The table above has also shown that from 3MP jumps directly too much too VGA and this camera has no option of 2MP and 1. 3MP, but other cameras have it. When using digital zoom for video, the camera can take up to 382. 6x magnification in VGA with Deteriorated image quality, but because video take multiframes per second, so between Deteriorated image quality and Undeteriorated image quality will be not much different. Nowadays cameras usually have iZoom with usually additional magnification 2x of its optical zoom, the iZoom use only center of the lens and not make any interpolation to original full resolution, so it save its good images quality in reduced resolution. The terms among camera manufacturers are “Smart Zoom”, “Safe Zoom”, there is also camera with digital zoom 7. 2x and smartzoom with approximately 30x total zoom for 7MP from 16MP total resolution and also 144x total zoom for VGA 640x480. Some photographers purposefully employ digital zoom for the low fidelity appearance of the images it produces. This community thinks that poor quality photographs imply the carelessness of the photographer and thus, the notion that it is possible to achieve authenticity through pre-meditated carelessness also inspires Lo-fi music. Image scaling Teleside converter - a secondary lens made for fixed lenses that increases the focal length, uses as a filter Zoom lens
Digital zoom was used to make the middle photo from the top photo, image quality is lost, while the lens was zoomed-in optically for the bottom photo, no quality is lost. Typically, the digital zoom would not be available until after the optical zoom had been exhausted.
Handheld. Zoom 10x, Optical zoom 10x, 2MP from 16MP maximum, ISO800, 1/420, F14.0, image is clear
Handheld. Zoom 28x, Optical zoom 10x and Digital zoom 2.8x, 2MP from 16MP maximum, ISO800, 1/420, F14.0, initial of deteriorated digital zoom, image is still clear
Handheld. Zoom 40x, Optical zoom 10x and Digital zoom 4.0x, 2MP from 16MP maximum, ISO800, 1/500, F14.0, image is still clear with some noise. Magnification in deteriorated digital zoom zone is 40x:28=1.4x