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

Reply
 
Thread Tools Search this Thread
Old Apr 22, 2008, 12:55 AM   #1
Junior Member
 
Join Date: Apr 2008
Posts: 4
Default

hi nI´m new here.

First questions to know the power of a ditigal objetive I have red that you must divide large mm/ low mm.

I explain a 40-400mm objetive should have 400/40=x10 power.

Is that correct?

So with is the sense to sel Olympus E-350 with

objetive 14-42mm=x3.5

objetive 40-150m=+3.75
facaphotos is offline   Reply With Quote
Sponsored Links
Old Apr 22, 2008, 5:12 AM   #2
Senior Member
 
rjseeney's Avatar
 
Join Date: Dec 2004
Location: Taylor Mill, Kentucky
Posts: 2,398
Default

facaphotos wrote:
Quote:
hi nI´m new here.

First questions to know the power of a ditigal objetive I have red that you must divide large mm/ low mm.

I explain a 40-400mm objetive should have 400/40=x10 power.

Is that correct?

So with is the sense to sel Olympus E-350 with

objetive 14-42mm=x3.5

objetive 40-150m=+3.75
As you can see, the zoom factor, or "x" doesn't mean much. A higher number does indicate a greater focal range, but it's a term created by marketers, and implies nothing about the quality of, or function of a lens, especially when talking about DSLR's. It is a bit more useful when comparing P&S cameras as their lenses are fixed. What really matters is the focal length. The lower the mm, the wider the view, the higher the number the narrower the view (telephoto).
rjseeney is offline   Reply With Quote
Old Apr 22, 2008, 7:04 AM   #3
Senior Member
 
Bob Nichol's Avatar
 
Join Date: Apr 2003
Location: Eastern Ontario Canada
Posts: 822
Default

Tamron has a web page that shows the view possible for a particular 35mm or DSLR lens http://www.tamron.com/lenses/learnin...comparison.php

As rjseeny pointed out the 'X' factor is meaningless in the DSLR environment as there are no fixed wide and telephoto standards. The 'X' factor is even becoming less useful in the bridge and compact camera world as they start getting more wide angle coverage.

In your Olympus example the two lenses cover from 14mm to 150mm which gives you good wide coverage to medium telephoto for general photography.


Bob Nichol is offline   Reply With Quote
Old Apr 22, 2008, 7:22 AM   #4
Junior Member
 
Join Date: Apr 2008
Posts: 4
Default

hi I see you point but I wanted to know that to compare my actual Panasonic x12 leica stock objetive to SLR objetives to choose correctly :?
facaphotos is offline   Reply With Quote
Old Apr 22, 2008, 7:34 AM   #5
Senior Member
 
Bob Nichol's Avatar
 
Join Date: Apr 2003
Location: Eastern Ontario Canada
Posts: 822
Default

A Leica DC Vario-Elmarit lens on the DMC-FZ50 has a 12x optical zoom (35mm equivalent = 35mm to 420mm).

The
35mm equivalent of the two Olympus lenses would be 28mm to 300mm so you would get wider coverage but not as much telephoto.

Olympus DSLRs have a sensor smaller then a 35mm film frame so they have a crop factor or focal length multiplier of 2. See http://www.dpreview.com/learn/?/Glos...tiplier_01.htm for an explanation.


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 6:57 AM.