Graflex.org Forum Index Graflex.org
Get help with your Graflex questions here
 
 FAQFAQ   SearchSearch   MemberlistMemberlist   UsergroupsUsergroups   RegisterRegister 
 ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log inLog in 

Lens Length Question

 
Post new topic   Reply to topic    Graflex.org Forum Index -> Lenses Help
View previous topic :: View next topic  
Author Message
dmyhand1957



Joined: 02 Feb 2008
Posts: 5
Location: Texas

PostPosted: Mon Mar 03, 2008 4:59 pm    Post subject: Lens Length Question Reply with quote

Sometimes, when looking at eBay or other sites, I see a lens with inches in the focal length description rather than mm. How should this be translated? I have always used 25mm per inch when working with Artillery. A French 75mm is just about the same bore diameter as a 3 inch Naval Gun. Will the same formula work with lenses? If not, why not? Thanks, Dennis
Back to top
View user's profile Send private message
Henry



Joined: 09 May 2001
Posts: 1636
Location: Allentown, Pennsylvania

PostPosted: Mon Mar 03, 2008 6:38 pm    Post subject: Reply with quote

One inch = 25.4 mm whether you are measuring guns, lenses, or the length of your ... nose. So to convert inches to mm, multiply inches by 25.4. Conversely, to convert mm to inches, divide mm by 25.4. A 101mm focal length lens = 3.97xxxxx, or 4 inches (101/25.4). Have fun!
Back to top
View user's profile Send private message
dmyhand1957



Joined: 02 Feb 2008
Posts: 5
Location: Texas

PostPosted: Mon Mar 03, 2008 7:44 pm    Post subject: Reply with quote

Cool. Thanks. I'll remember that if I'm measuring my lens, or my...nose!
Back to top
View user's profile Send private message
Display posts from previous:   
Post new topic   Reply to topic    Graflex.org Forum Index -> Lenses Help All times are GMT
Page 1 of 1

 
Jump to:  
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
You cannot vote in polls in this forum


Powered by phpBB © 2001, 2005 phpBB Group