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

Reply
 
Thread Tools Search this Thread
Old Jan 26, 2010, 9:05 AM   #1
Senior Member
 
Widowmaker's Avatar
 
Join Date: Jul 2003
Location: Bakersfield, CA
Posts: 851
Default 400 5.6 - 300 4 is mfd

I know the 400 has no IS and Im not that concerned about that part. I already know the 300 4 IS is sharp and with the 1.4 tc is still nice. I'm wondering about the MFD of each lens. The 400 is something like 11 feet and I think the 300 is near 5 feet. Now with that in mind the 300 will actually have better magnification right? For example take a test subject at the MFD of the 400 and then the same subject at the MFD of the 300... the subject will actually fill more of the frame on the 300 shot correct ?

I know that will matter as far as versatility but with birding being one of the main purposes Im wondering if that really matters. Unless your in a blind, how often with you be 5 feet from a bird ?
Widowmaker is offline   Reply With Quote
Sponsored Links
Old Jan 26, 2010, 10:30 AM   #2
Senior Member
 
TCav's Avatar
 
Join Date: Sep 2005
Location: Washington, DC, Metro Area, Maryland
Posts: 13,544
Default

The EF 300mm f/4L IS USM has a diagonal angle of view of 8.25 and a mfd of 58.8 inches. At it's mfd, the frame would have a diagonal measurement of 8.5 inches.

The EF 400mm f/5.6L USM has a diagonal angle of view of 6.17 and a mfd of 138 inches. At it's mfd, the frame would have a diagonal measurement of 14.85 inches.

The hypoteneuse of a 'Full Frame' image sensor is 1.7 inches.

That gives the EF 300mm f/4L IS USM a magnification ratio of ~1:5, and the EF 400mm f/5.6L USM a magnification ratio of ~1:8.75
__________________
  • The lens is the thing.
  • 'Full Frame' is the new 'Medium Format'.
  • "One good test is worth a thousand expert opinions." - Tex Johnston, Boeing 707 test pilot.

Last edited by TCav; Jan 26, 2010 at 10:33 AM.
TCav 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 9:27 PM.