Free Shipping on ALL Products
camera reviewsbest cameraslens reviewsphotography tipscamera forumvideo toursphotography bookssupport me
It is currently Thu Oct 23, 2014 9:08 pm

All times are UTC




Post new topic Reply to topic  [ 4 posts ] 
Author Message
 Post subject: Aperture Lingo
PostPosted: Mon Mar 26, 2012 5:07 am 
Offline

Joined: Wed Jun 22, 2011 3:53 am
Posts: 48
Hello,

Just a couple questions on Aperture lingo.

stoping down would mean eg changing from f4 to f8?

wide open would mean e.g. on a 50mm 1.4 setting to f1.4?

Do all lenses have a sweet spot Ap wise? From reading lens reviews here and in other places I've come to realize the expensive lenses keep a fairly consistent quality through all Ap ranges but in good lighting conditions I see many lens x vs lens y sharpness tests people test at f11 a lot. Just coincidence or is f11 a "sweet" spot under good light?


Thx for any answers!

_________________
Canon 60D
EF-S 15 - 85 IS USM
EF 70 - 300 IS
EF 50 1.4
EF 100 - 400L


Top
 Profile  
 
 Post subject: Re: Aperture Lingo
PostPosted: Mon Mar 26, 2012 7:59 am 
Offline
User avatar

Joined: Sat Feb 09, 2008 9:06 am
Posts: 386
Location: Manchester (UK)
The general rule of thumb seems to be that lenses perform best two stops down from their max aperture. Obviously each lens is different and more expensive lenses are engineered to better tolerances.

_________________
Canon EOS 400D, EF-S 18-55mm, EF 24-105mm f/4L IS USM, EF 50mm f/1.8 MK I, EF-S 10-22mm, EF 70-200mm f/4L IS USM, EF 35mm f/2 IS, EF 85mm f/1.8
Canon 430EX II, Manfrotto 055CXPRO3, Arca Swiss P0
Panasonic GX1, Panasonic 20mm f/1.7, Olympus 45mm f/1.8
Canon EOS 30/33 and Pentax MX/ME Super

MY FLICKR!


Top
 Profile  
 
 Post subject: Re: Aperture Lingo
PostPosted: Mon Mar 26, 2012 5:29 pm 
Offline

Joined: Wed Jun 22, 2011 3:53 am
Posts: 48
2 stops down from a maximum on a 50 mm 1.4 would be 1.8 or 3.6?

_________________
Canon 60D
EF-S 15 - 85 IS USM
EF 70 - 300 IS
EF 50 1.4
EF 100 - 400L


Top
 Profile  
 
 Post subject: Re: Aperture Lingo
PostPosted: Mon Mar 26, 2012 5:57 pm 
Offline
User avatar

Joined: Mon Aug 17, 2009 9:46 pm
Posts: 947
Location: Norway
f/1.8 is 2/3 stops down from f/1.4. Each stop down halves the aperture area, that is divides the f-number by sqrt(2) which is about 1.4.
That means 2 stops down from f/1.4 is f/2.8

_________________
Some flappy mirrors and lots of glass


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: Exabot [Bot] and 1 guest


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