Go Back   Steve's Digicams Forums >

LinkBack Thread Tools Search this Thread
Old Aug 6, 2006, 9:24 PM   #1
Senior Member
Contriver's Avatar
Join Date: Aug 2006
Posts: 268

I am considering purchasing a low-end DSLR as my next camera purchase, but I don't know anything about lenses. Does anyone know ofa website which has abeginner's guides to lenses?

Oneexample of something that confuses me is: One DSLR I am looking at is a refurbished Digital Rebel which comes with a Canon EF-S 18-55mm, f3.5-5.6 zoom lens. Why does it say f3.5-5.6? Why such a small range? Also, I figure since this lens is only a 55mm, I might need a telephoto lens as well. I found this on Amazon for $199: "Canon EF 80-200mm f/4.5-5.6 II Telephoto Zoom Lens". Again, why such a small f-number range? Are there 80-200mm lenses which offer a greater range? Is there some technicalhangup that prevents a lens from having a better range?
Contriver is offline   Reply With Quote
Sponsored Links
Old Aug 7, 2006, 1:45 AM   #2
Senior Member
jacks's Avatar
Join Date: May 2005
Posts: 221

The f-stop numbers are the widest apertures, not a range of possible apertures. 18-55f3.5-5.6 means the lens can do f3.5 at 18mm but only f5.6 at 55mm. At any focal length it can be stopped down to much higher f-stop numbers.
jacks is offline   Reply With Quote
Old Aug 7, 2006, 10:21 AM   #3
Senior Member
Wildman's Avatar
Join Date: Oct 2002
Posts: 544

Get your hands on Canon's EF Lens Work III. It's really a big advertisement, but covers everything you'd ever want to know about fields of view, f-stops, etc. as well as manufacturing processes. Each lens in Canon's lineup (at publishing time) is covered specifically, complete with some beautiful photos. While the lens write-ups are Canon specific, most of the information is pretty generic.

You might find the book in a large library. I got my copy free of charge when I bought my EOS 20D from Canoga Camera.
Wildman is offline   Reply With Quote

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 On
Pingbacks are On
Refbacks are On

All times are GMT -5. The time now is 4:34 PM.