Join for FREE
It only takes a minute!
Magnifying the passion for nature. Zeiss Victory Harpia 95. New!

Welcome to BirdForum.
BirdForum is the net's largest birding community, dedicated to wild birds and birding, and is absolutely FREE! You are most welcome to register for an account, which allows you to take part in lively discussions in the forum, post your pictures in the gallery and more.

Reply
 
Thread Tools Rate Thread
Old Monday 2nd May 2016, 03:49   #1
Peter Ericsson
Registered User
 
Peter Ericsson's Avatar

 
Join Date: Jul 2003
Location: Bangkok
Posts: 1,473
DOF with 1.4 and 2.0

Someone told me that the two above mentioned extenders give the same dof when used on a 600mm lens.

Since one gives a focal length of 840 and the other 1200 shouldn't the dof be more shallow with the 2.0? (using the same aperture)

Peter
__________________
I honestly think it is better to be a failure at something you love than to be a success at something you hate. —George Burns
Peter Ericsson is offline  
Reply With Quote
Old Monday 2nd May 2016, 06:30   #2
GraemeS
Sporadic user
 
GraemeS's Avatar

 
Join Date: Jul 2012
Location: Thailand
Posts: 214
Since they also change the f number, dof should be unchanged I think.
Graeme
__________________
Graeme S
https://www.flickr.com/photos/gjsheppard/
Moved from 7D with 70-300L to E-M1 with 75-300. My shoulder is happy, at the very least.
Now have a 300mm f4 PRO. My dream lens.
GraemeS is offline  
Reply With Quote
Old Monday 2nd May 2016, 06:40   #3
GraemeS
Sporadic user
 
GraemeS's Avatar

 
Join Date: Jul 2012
Location: Thailand
Posts: 214
Sorry, just reread so to clarify:
If you keep aperture constant then yes, dof will change due to changing length.
If you allow aperture to change by keeping it wide open, dof will not change.
__________________
Graeme S
https://www.flickr.com/photos/gjsheppard/
Moved from 7D with 70-300L to E-M1 with 75-300. My shoulder is happy, at the very least.
Now have a 300mm f4 PRO. My dream lens.

Last edited by GraemeS : Monday 2nd May 2016 at 06:42. Reason: Typo!
GraemeS is offline  
Reply With Quote
Advertisement
Reply


Thread Tools
Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is Off
HTML code is Off

{googleads}

Fatbirder's Top 1000 Birding Websites

Help support BirdForum

Page generated in 0.14149499 seconds with 13 queries
All times are GMT. The time now is 10:12.