Free Shipping on ALL Products
camera reviewsbest cameraslens reviewsphotography tipscamera forumvideo toursphotography bookssupport me
It is currently Sat Aug 23, 2014 3:20 pm

All times are UTC




Post new topic Reply to topic  [ 4 posts ] 
Author Message
PostPosted: Thu May 19, 2011 4:05 am 
Offline
User avatar

Joined: Tue Apr 26, 2011 4:15 pm
Posts: 920
Location: Kanduhar, Afghanistan
My T2i is coming with the Sigma 18-125mm f/3.8-5.6 DC OS HSM lens. In reading reviews on www.the-digital-picture.com they said that this lens is for 1.6 crop factor bodies only. Would that mean that they have taken the crop factor into consideration? I was figuring since this is a 18-125mm, with the crop factor it would be 28-200mm. I got to thinking about it what if they took the crop factor into consideration and I'm actually getting a 18-125mm.

I've been trying not to think too much about crop factor but this is a kit lens and I plan on in the future to get nicer lenses and this one was going to be to help me decide what sizes to get. I know this sounds odd. Basically, if this is a true 18mm lens then I know if I go get another 18mm lens I'll have the same field of view. But if they have adjusted for the crop factor then I go get another 18mm lens I won't have the same field of view. Sorry I know I ramble :oops:

_________________
Mike "The Squirrel"
Canon 550D | Canon EF 35mm 1:2 | Canon 50 f/1.8 II | Sigma 18-125mm DC OS | Tamron SP 70-300mm Di VC USD | Canon 430EX II
Military Issued Canon 40D | Canon 55-250mm IS


Top
 Profile  
 
 Post subject:
PostPosted: Thu May 19, 2011 8:54 am 
Offline

Joined: Tue Jul 13, 2010 8:47 pm
Posts: 202
Location: Osijek
for all lenses that exist numbers written on them are the real focal lenght. if you have sensor with crop factor you multiply.

for this particular lens, designed for cropped cameras means that it's "hole" for light is big enough to light the aps-c sensor, so if you mount it on full frame sensor you would get a black circle around the edges where light didn't get to...

cheers

_________________
nikon d90 --->af-s dx 18-105mm; tamron 90mm macro

add me up on:

flickr:
http://www.flickr.com/photos/bakica/

deviant art:
http://tbensic.deviantart.com/

----:>bakice ce vladati svjetom<:----


Top
 Profile  
 
 Post subject:
PostPosted: Thu May 19, 2011 10:03 am 
Offline
User avatar

Joined: Mon Aug 17, 2009 9:46 pm
Posts: 947
Location: Norway
The focal length stays the same no matter how small or big a sensor you put the lens in front of. What changes is the field of view. To be able to relate the field of view of different lenses on differently sized sensor we use the 35mm equivalent focal length, i.e. the focal length you would need to get the same coverage on full frame or 35mm film

_________________
Some flappy mirrors and lots of glass


Top
 Profile  
 
 Post subject:
PostPosted: Thu May 19, 2011 2:13 pm 
Offline
User avatar

Joined: Tue Apr 26, 2011 4:15 pm
Posts: 920
Location: Kanduhar, Afghanistan
ok, thanks guys!

_________________
Mike "The Squirrel"
Canon 550D | Canon EF 35mm 1:2 | Canon 50 f/1.8 II | Sigma 18-125mm DC OS | Tamron SP 70-300mm Di VC USD | Canon 430EX II
Military Issued Canon 40D | Canon 55-250mm IS


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 4 posts ] 

All times are UTC


Who is online

Users browsing this forum: No registered users and 3 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum

Search for:
Jump to:  

All words, images, videos and layout, copyright 2005-2012 Gordon Laing. May not be used without permission.
/ How we test / Best Cameras / Advertising / Camera reviews / Supporting Camera Labs

Webdesign by Alphabase IT
Powered by phpBB® Forum Software © phpBB Group