Go Back   Steve's Digicams Forums > Digital SLR and Interchangeable Lens Cameras > Nikon Lenses

Reply
 
Thread Tools Search this Thread
Old Sep 10, 2008, 3:30 PM   #1
Senior Member
 
Join Date: May 2008
Posts: 136
Default

Hello. I am a bit confused about focal lenghts in DX format...

By instance, a 18-55mm kit DX lens for the D40 is equal to those focal lenghts x 1.5 on a FX camera? If so, let's say ifI use a 18-55mm lens designed for a FX camera...will that factor be the same (1.5) ? :?



Thanks!


artmustel is offline   Reply With Quote
Sponsored Links
Old Sep 10, 2008, 4:12 PM   #2
Senior Member
 
goomer's Avatar
 
Join Date: Apr 2005
Location: Kamloops, B.C.
Posts: 378
Default

sorry, I totally misunderstood your question...yes, if you put a full frame lens (FX or other full frame lens) on a Dx camera you get the 1.5 crop factor which gives you the 35 mm equivalent focal length.
goomer is offline   Reply With Quote
Old Sep 10, 2008, 5:35 PM   #3
Senior Member
 
Join Date: May 2008
Posts: 136
Default

Goomer, I still have doubts about all this.

If a18-55mm DX lens on the D40 gives the equivalent of 27-82.5mm in a 35mm camera, then a 18-55mm lens designed for a 35mm camera if installed on the D40 will give the same factor of 1.5x, 27-82mm?

Thanks.
artmustel is offline   Reply With Quote
Old Sep 10, 2008, 6:09 PM   #4
Senior Member
 
ReneB3's Avatar
 
Join Date: Jul 2005
Posts: 193
Default

Yes, it is the same. They don't use different focal lengths for the FX or DX lenses. All are designated for the FX or 35mm based focal lengths and we have to use the 1.5 conversion factor for our DX cameras.
ReneB3 is offline   Reply With Quote
Old Sep 10, 2008, 8:00 PM   #5
Senior Member
 
tjsnaps's Avatar
 
Join Date: Apr 2007
Location: Sacramento, Ca
Posts: 652
Default

Maybe this will help

The mm designation on a lens in simply a measurement of the distance between the main element of the lens and the film or in the case of digital, the censor. It is the size of the film or censor that determines the angle of view the lens will produce. Therefore a lens of any given focal length , say 80mm , will give the same angle of view on a DX camera no mater what type of camera the lens was designed for.

The 1.5 crop factor is designed to make it easier for people who are used to shooting in 35mm to judge the effect of their lenses when used on a DX camera. But if you never used 35mm cameras it might only serve to confuse you.

This is nothing new to photography people who switched between 35mm and 220 film went through the same process.

tjsnaps is offline   Reply With Quote
Old Sep 10, 2008, 8:45 PM   #6
Senior Member
 
Join Date: May 2008
Posts: 136
Default

Thanks to you all!


artmustel 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 2:02 AM.