Go Back   Steve's Digicams Forums > Digicam Help > General Discussion

Reply
 
Thread Tools Search this Thread
Old Feb 11, 2007, 10:36 AM   #1
Junior Member
 
Join Date: Sep 2006
Posts: 21
Default

Hi Friends,

How do I inturpret the numbers on a reference guide about the feature on a camera called Zoom optical/digital? What kind of information are those numbers giving me, and how do I use them?

Thanks
Sunbeam35 is offline   Reply With Quote
Sponsored Links
Old Feb 11, 2007, 11:57 AM   #2
Senior Member
 
TCav's Avatar
 
Join Date: Sep 2005
Location: Washington, DC, Metro Area, Maryland
Posts: 13,544
Default

Sunbeam35 wrote:
Quote:
How do I inturpret the numbers on a reference guide about the feature on a camera called Zoom optical/digital? What kind of information are those numbers giving me, and how do I use them?
Could you be more specific about the numbers that appear in your reference giude, and for which camera? It is possible that this guide is using 35mm equivalents when it discusses "zoom", and that would be helpful to someone using your camera who is familiar with 35mm photography, but if you have no experience with 35mm cameras then this information is meaningless to you. But without knowing the specific contents of your reference guide, I can't be certain.

In general, I can say that "optical zoom" refers to the camera's ability to manipulate the elements of the lens in order to change its focal length. A longer focal length has a narrower field of view, and therefore, a higher magnification, so distant objects appear closer (this is referred to as "zooming in"). A shorter focal length has a wider field of view, so as to include more of the periphery into the image (this is referred to as "zooming out".)

Alternatively, "digital zoom" is the camera's ability to adjust its field of view by simply ignoring the outer portions of the image sensor. That is, when you select a 2X (or 2 power)(not 2 times) digital zoom, a camera with a 3000 x 2000 pixel image sensor will ignore the outer portion of the sensor and construct an image from just the center 1500 x 1000 pixels, in order to narrow the field of view. This reduces the resolution of the image.

But again, without knowing the specific numbers in your reference guide, I can't give you a specific answer.
TCav is offline   Reply With Quote
Old Feb 11, 2007, 1:28 PM   #3
Senior Member
 
Caboose's Avatar
 
Join Date: Feb 2005
Posts: 625
Default

Digital zoom is basically the same thing as down loading your image and cropping it in a image editting program except it is done in your camera. This usually doesn't give your the best image quality. I would recommend you turn that option off. If the numbers you are refering to are something like 5.8 - 17.4mm that is the actual focal lenth of the lens on your digacam.Because of the size of the sensor in your camera the 35mm camera equilvalent focal lenght would read something like35mm-105mm. If you are looking at the numbers like 3x optical 4xdigital zoom this is just the ratio between the short focal length and the long focal length, which is pretty much useless information.




Caboose is offline   Reply With Quote
 
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -5. The time now is 1:20 PM.