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

Reply
 
Thread Tools Search this Thread
Old Nov 12, 2006, 10:48 PM   #1
Senior Member
 
aladyforty's Avatar
 
Join Date: Jan 2004
Posts: 6,964
Default

Looking at some tamron lenses I noticed the word "Aspherical" used. Is this the equivalent of ultrasonic on a canon lens?
aladyforty is offline   Reply With Quote
Sponsored Links
Old Nov 12, 2006, 11:14 PM   #2
Senior Member
 
Join Date: Jun 2005
Posts: 804
Default

"Aspherical" is a lens design that helps to maintain a more uniform sharpness and color rendition over the entire coverage area. Aspherical elements are harder to produce than non-aspherical elements, so their incorporation jacks up the price of the lens.

Grant
granthagen is offline   Reply With Quote
Old Nov 13, 2006, 12:27 AM   #3
Senior Member
 
aladyforty's Avatar
 
Join Date: Jan 2004
Posts: 6,964
Default

Thanks:-)
aladyforty is offline   Reply With Quote
Old Nov 13, 2006, 9:16 PM   #4
Senior Member
 
Bob Nichol's Avatar
 
Join Date: Apr 2003
Location: Eastern Ontario Canada
Posts: 822
Default

http://en.wikipedia.org/wiki/Aspherical_lens

An aspheric lens or asphere is a lens whose surfaces have a profile that is neither a portion of a sphere nor of a circular cylinder. In photography, a lens assembly that includes an aspheric element is often called an aspherical lens.
Bob Nichol 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 2:33 PM.