What is the difference between digital zoom and optical zoom?

[digitized]

Hi,

Just wanted to know as above. My new powershot A540 has 3X digital/4X optical zoom. My friend's S3IS has 10X optical zoom. What do these terms mean?

[Cool G5]

Digital zoom refers to the zooming by the software.It leads to poor quality of the picture.

Optical means zooming by the lens of the camera(the lens moves forward).
Optical zoom should be used as it does not reduces the quality of the picture.

Also check this out:http://www.photoxels.com/article-optical-digital-zoom.html

[ThinkFree]

Opticall Zoom is achieved by actual movement of the lens while in Digital zoom no movement of lens is there(You may see lens moving in /out when you zoom on a thing optically but not in case of optical zoom) . Digital Zoom may reduce the quality of your photographs so avoid using it every time.

[sysfilez]

digital zoom actually crops the image, u have have a lot of camera shake doing the same. not recommended @ all. always use optical zoom. digial zoom is allshit.

[nithinks]

already discussed .. search before you post...

[digitized]

^^^Where exactly?

This (http://www.thinkdigit.com/forum/showthread.php?t=44529) only discusses what is digital zoom, not the difference.

[sakumar79]

Scroll down to the bottom of the page and you will see lot of similar threads... Optical zoom is actual zoom, similar to a regular camera having focus 35-105mm specification... Digital zoom is where the camera does not adjust the focus but instead crops the image into smaller portion. Typically, optical zoom is considered important while digital zoom is not necessary at all...

Arun