www.photomacrography.net :: View topic - How to find a tube lens for Nikon AZ Plan 5x/0.5 objective?
www.photomacrography.net Forum Index
An online community dedicated to the practices of photomacrography, close-up and macro photography, and photomicrography.
Photomacrography Front Page Amateurmicrography Front Page
Old Forums/Galleries
 
 FAQFAQ   SearchSearch   MemberlistMemberlist   UsergroupsUsergroups   RegisterRegister 
 ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log inLog in 
How to find a tube lens for Nikon AZ Plan 5x/0.5 objective?
Goto page Previous  1, 2
 
Post new topic   Reply to topic    www.photomacrography.net Forum Index -> Equipment Discussions
View previous topic :: View next topic  
Author Message
rjlittlefield
Site Admin


Joined: 01 Aug 2006
Posts: 19249
Location: Richland, Washington State, USA

PostPosted: Wed May 16, 2018 6:23 pm    Post subject: Reply with quote

JohnyM wrote:
20x lens i've tested, covers FF sensor on 135mm tube, but with ~1,5mm infinity space.

True, a longer tube lens at same f# will have a larger diameter aperture, which may give more infinity space. But the details will depend on entrance pupil location for each tube lens. What sort of 135 mm lens were you using it with?

--Rik
Back to top
View user's profile Send private message Visit poster's website
JohnyM



Joined: 24 Dec 2013
Posts: 338

PostPosted: Thu May 17, 2018 5:59 am    Post subject: Reply with quote

Reversed 135mm Agfa Repromaster F8 or F9 (same lens is sometimes marked as F8 and sometimes as F9 - mine have no marks beside focal lenght - so i assume it's something in between).

Despite being quite slow (pretty much matching 20/0,75 [pulled to 13,5x] aperture), entrance pupil is very "accesible" (for the lack of better word) + it doesnt have glaring problems i've noticed with raynox, or that ugly ring from reflected objective mount.

Im in the process of manufacturing better adapter, can provide photos in a week or two.
Back to top
View user's profile Send private message
rjlittlefield
Site Admin


Joined: 01 Aug 2006
Posts: 19249
Location: Richland, Washington State, USA

PostPosted: Thu May 17, 2018 8:28 am    Post subject: Reply with quote

JohnyM wrote:
Reversed 135mm Agfa Repromaster F8 or F9

So, aperture diameter is only about 16 mm? That definitely explains the short infinity section, especially on FF.

--Rik
Back to top
View user's profile Send private message Visit poster's website
JohnyM



Joined: 24 Dec 2013
Posts: 338

PostPosted: Thu May 17, 2018 9:28 am    Post subject: Reply with quote

Yes, almost 16 according to my measurements. Other, faster 135mm lenses i've tested, had very recessed aperture and were vignetting horribly.

~120ish raynox is also vignetting, but seems it's already objective fault here. Also for raynox, some serious flocking would be necessary.

Anyway, it just occured to me (why only now)... why bother with infinite space, i can just use finite vertical illuminator above the tube lens.
Back to top
View user's profile Send private message
rjlittlefield
Site Admin


Joined: 01 Aug 2006
Posts: 19249
Location: Richland, Washington State, USA

PostPosted: Thu May 17, 2018 9:54 am    Post subject: Reply with quote

JohnyM wrote:
Anyway, it just occured to me (why only now)... why bother with infinite space, i can just use finite vertical illuminator above the tube lens.

That should work fine, all the same issues as with finite objective. Maybe some extra problems with reflections because of more glass surfaces.

I would be interested to see the setup after you get it working.

--Rik
Back to top
View user's profile Send private message Visit poster's website
Display posts from previous:   
Post new topic   Reply to topic    www.photomacrography.net Forum Index -> Equipment Discussions All times are GMT - 7 Hours
Goto page Previous  1, 2
Page 2 of 2

 
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