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 

Graflex/Graphic thread sizes?

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



Joined: 04 Apr 2006
Posts: 155
Location: Calgary AB Canada

PostPosted: Mon Aug 04, 2008 7:54 pm    Post subject: Graflex/Graphic thread sizes? Reply with quote

I have an RB Graflex Ser. B 3x4 (no interchangeable lens board) and a 10-inch Tele-Optar lens (with retaining ring) which was obviously made for a Graphic or a Graflex with interchangeable lens boards. The 10-inch Tele-Optar is listed in Graflex Graphic Photography as the telephoto lens which can be used with the 3x4 Series B, and it focuses nicely at infinity to within less than 5 feet when I hold it against the camera. The tread sizes are different, though. They appear to be of the same diameter, but the thread pitch is finer on the lens.
I've inquired at S. K. Grimes about having an adapter ring made and they told me it would be best to send them the two surfaces to be mated, which would mean sending the lens board as well as the lens. I'm leery of detaching the board from the camera (4 screws and perhaps glue?).
I'm wondering if anyone knows the exact thread sizes. Grimes has sent instructions for measuring, but of course they can't guarantee a correct fit without having the surfaces at hand.
I'd be very grateful if someone who has reliable info would fill me in.
Back to top
View user's profile Send private message Send e-mail
Dan Fromm



Joined: 14 May 2001
Posts: 1892
Location: New Jersey

PostPosted: Mon Aug 04, 2008 11:07 pm    Post subject: Reply with quote

Billy, if both threads have the same diameter, how will the adapter work? I ask because IIRC y'r lens isn't threaded at the rear end of its barrel, but some distance forwards.
Back to top
View user's profile Send private message
Billy Canuck



Joined: 04 Apr 2006
Posts: 155
Location: Calgary AB Canada

PostPosted: Tue Aug 05, 2008 1:36 am    Post subject: Reply with quote

The way I figure it is like this: The rear of the lens projects into the camera about 19mm beyond the thread. There is no problem fitting the lens into the camera, holding the threads against each other. The adapter ring would have a male thread to fit into the camera front and a female thread to fit the lens and a narrow space in between to keep the threads separate.
According to my (very limited) mechanical understanding this should work. The lens of course would sit 4-5mm farther out than it would if it were threaded correctly for the Graflex, but since it focuses OK when I hold it in the position it would be if it were held by a ring, that shouldn't present a problem. I think.
I may be completely wrong, but SK Grimes didn't appear to think the idea was not feasible.
Back to top
View user's profile Send private message Send e-mail
Dan Fromm



Joined: 14 May 2001
Posts: 1892
Location: New Jersey

PostPosted: Tue Aug 05, 2008 8:45 am    Post subject: Reply with quote

Thanks for the reply. I hate to use them, but a thread gauge should get the answer you need.
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