What is the difference between optical zoom and digital zoom in digital cameras?

Question

And please tell me what is a good number for both zooms. Thanks!

Answer 1

Optical is the actual "Zooming" of the lens it moves the lens in and out, which the bigger that number the better digital is just just the sensor in the camera "Zooming." You should have about 4x Optical and about 8x Digital.

Answer 2

OPTICAL zoom works using LIGHT.
All lenses, in both FILM and DIGITAL, mark out the boundaries of the subject area and hence the area from where light will be received. (50 mm is generally taken as "what the eye sees"; zoom lenses reduces the subject area that is "visible" but as it fills the same size of "screen", the subject looks BIGGER).
>>>> After the light is "inside" the digital camera then it gets pixellated on the digital light sensor. At this point, the light sensor technology is 100% representative of the light that has been received.
>>>> DIGITAL ZOOM is the feature that "tries" to make a part of the captured image bigger. It can only do this by making the pixells bigger. The bigger the pixells, the fuzzier the image becomes. Mind you, there are some clever algorithms that try and "fill in" new pixells, but these new pixells are not "original" pixells and are generated based on the "neighboring pixells". So short answer, digital zooming is not really beneficial with the prosumer cameras and software, but maybe works for satellite technology (best to confirm that with NASA!).
>>>> OPTICAL ZOOM preferred size? As big as you can afford and pick the good lens companies like Canon, Tamron, Sigma, Nikon etc.
>>>> DIGITAL ZOOM preferred number? Maybe in PHOTOSHOP (or similar digital image processing software) you might get away with a factor of 2 or 3, again though it depends on the pixell density of your original image and the output medium.
John Mc

Answer 3

The way optical and digital zooms work are quite different from each other.

An optical zoom works by using the physical legs to magnify the image coming into the camera. This is how film cameras, telescopes and microscopes work.

A digital zoom works by taking the center of the image (cropping) and enlarging it to look as if you have actually zoomed in. Digital zoom does not provide any more detail as only a fraction of the CCD inside the camera is now been used to record the photo, the rest of the image is been thrown away thanks to the digital zoom.

In reality digital zoom is of no use at all. If you want to 'zoom in' a little more you are better off taking the photo without any digital zoom and then editing the larger photo using your computer.

I recommend a three times optical zoom and don't worry what digital zoom a camera has as you should never use it.

I recommend reading the information on this site, it is a great guild to the facts on digital cameras:
http://www.steves-digicams.com/best_cameras.html

Answer 4

Digital zoom is done artificially by the CPU - it is data from the existing picture (in most cases you are better off not using any digital zoom at all and doing the "digital zooming" on the computer - it will often be of a higher quality that what s small digi-cam can do. Optical Zoom is done with the lens. Very high quality doing it with the lens. Four to eight times is about normal with the lens. ( 35 to 200 MM )

Answer 5

Digital zoom is done artificially by the CPU - it is interpolated data from the existing picture (in most cases you are better off not using any digital zoom at all and doing the "digital zooming" on the computer - it will often be of a higher quality that what s small digi-cam can do.

optical zoom is done by optics and it is the real thing.

enjoy

Answer 6

Optical zoom is "real" zoom and digital zoom sucks. Just totally ignore digital zoom and choose based on optical zoom.

Answer 7

optical zoom is the true zoom from the lens. More that 3x you will need a image stabilizer system (like 12x) in order to avoid the blurr.

Digital zoom is ... a scam.