On Wednesday 11 March 2009 03:37:14 pm Jeffrey Silverman wrote: > On Wed, Mar 11, 2009 at 3:21 PM, Asif Lodhi <asif.lodhi at gmail.com> wrote: > > Hi Jeffrey, > > > > On 3/11/09, Jeffrey Silverman <jeffrey.d.silverman at gmail.com> wrote: > >> <snip!> I also suspect many don't understand the > >> difference between optical > >> > >>> and digital zoom. > >> > >> There is a difference? > > > > Optical zoom: zooming rotating the *physical* knob > > around the lens. Digital zoom: mathematical estimation > > (interpolation) of the next zoom level of image size. > > > > Correct me if I am wrong, please. > > > > -Asif > > Sorry, that was my EXTREMELY dry humor[1]. I actually > know what the diff is. and yes, you are way wrong: > optical zoom is when the lens diffraction rate is 0.5 > times the distance to the optical interference, resulting > in noticeable noise, and digital zoom is when the lens is > circumvented through reverse interpolation of the optical > megapixels. Someone may be interested in expanding on > some of the minor details, but that is a good overview. > > > > > > [1] as in "Not Actually Funny(TM)" or "Funny Not > Included" Optical zoom means moving the lens elements around, just as on a film camera. I don't think this is a significant cause of noise, but of course it will vary from camera to camera. My Fujifilm E900 manual states that digital zoom lowers picture quality. I have an add-on lens to avoid overuse of digital zoom.
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