Ultron 35/1.7 close focus or Things that Cosina should have done to begin with.

Krosya

Krosya

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As you may already know, Cosina's Amazing Nokton 50/1.5 lens can be modified to focus closer:
IMG_0325.jpg


Well, as it turnes out, another superb lens by Cosina, - Ultron 35/1.7 has this same handicap - 0.9m clos focus (main reaon I sold one - twice! ):
IMG_0321.jpg


However, this can be fixed :
IMG_0322.jpg


IMG_0326.jpg


Now I have 2 superb lenses that focus to 0.7m! Something Cosina should have done to begin with. 🙄
Oh well, I'm happy that I was able to do this mod and greatly impove value and usability of 2 amazing lenss!
 
Last edited:
Sorry, boys and girls. - No pics of the mod. Didnt take them. But it's somewhat similar to Nokton 50/1.5 - see my other thread on that. This lens is a bit more complicated than Nokton - same idea, but some parts needed to be worked on with more care.
Didnt have a chance to take many pics with newly adjusted lens yet - here are just a few - at the new min focus distance of 0.7m wide open on RD1S (nothing earthshattering, just a few test shots):

EPSN6581.jpg


EPSN6582.jpg


May have missed focus on this one a bit:

EPSN6601.jpg


All in all - works great I think.
 
ooh, do you have a mod to add a focussing tab? My sample may be the exception, but the focussing is a bit stiff and the barrel isn't as easy to grip. I'd love to have a tab like the 35/2.5

What would you charge for the .7 focus mod?
 
I'm not sure if and how one could add a focus tab to this lens. Maybe it can be done. But I would rather re-lube the lens (which I did while doing this mod) and it's VERY smooth focusing now.
As far as doing this for someone else - well, I'm not sure I'm brave enough to risk damaging a lens thats not mine. Maybe, but I cant say one way or another at this point. Anyway, this can be discussed via PM. There are many things that could go wrong while doing this - I managed to nick a small part of the barrel while doing it - doesnt affect the performance in any way, but just looks a bit ugly.
 
Like I said in a post above - it's similar to a mod of the Nokton 50/1.5 for close focus - see my thread about it in this section of the forum. Ultron is somewhat different and a bit more difficult, but idea is the same.
 
Heavystar sells very hard plastic focusing tabs that are identical to the pre-ASPH Summilux tabs. You can carefully file the surface that will contact the lens down to match the lens' curvature. I just did this with my 21mm ZM lens. I don't like the Zeiss focusing bump so I added a tab to it. I used 3M outdoor-rated double-sided tape to attach it. Good so far, it's been a week of use and sliding in a pouch in my bag.

Prior to this I had made a few focusing tabs out of 3/16" plexiglass. I ground them down to the profile & shape I wanted then rubber cemented them to the lenses (old user Canon 35mm f/2 comes to mind). It's an easy accessory to make with some time and a file or dremel tool.

Phil Forrest
 
Doing the close-focus mod does not impede the use of the lens on any camera, but simply extends its range. The 35/1.2 Nokton goes down to 0.7m, which is nice. Having the Ultron close-focus will work with M-Mount cameras and maby LTM cameras as well. The Canon P will get in closer than 3ft with my close-focus modified Jupiter-3.
 
Phil_F_NM said:
Heavystar sells very hard plastic focusing tabs that are identical to the pre-ASPH Summilux tabs. You can carefully file the surface that will contact the lens down to match the lens' curvature. I just did this with my 21mm ZM lens. I don't like the Zeiss focusing bump so I added a tab to it. I used 3M outdoor-rated double-sided tape to attach it. Good so far, it's been a week of use and sliding in a pouch in my bag.

...

Phil Forrest
Click to expand...

Sorry to hijack the thread but could you please post pictures of the lens w/ focusing tab. I'm considering doing the exact same thing to my M-Hexanon 50/2
 
Never understood why Cosina did not build the Nokton's basis 0.7 meter close focus. One can only assume that they were not convinced of optical qualities at that distance.
Difficult to determine with jpeg's on the web. Did anybody close to Mr K ever pose (the bartender or Tom A. for example) that question ?

BTW still thinking about having my 50/1.5 modified, but it is not cheap (something like EUR 150), although of course a lot cheaper than buying a summilux.
 
Brian Sweeney said:
Doing the close-focus mod does not impede the use of the lens on any camera, but simply extends its range. The 35/1.2 Nokton goes down to 0.7m, which is nice. Having the Ultron close-focus will work with M-Mount cameras and maby LTM cameras as well. The Canon P will get in closer than 3ft with my close-focus modified Jupiter-3.
Click to expand...

So true. I used to have a Canon 7 ltm body that had RF coupling to even lower than 0.7m. So IMO this is a huge advantage. Actually that was the main reason I sold wonderful UC -Hexanon 35/2 since it only focused down to 0.9m.
 
I figured that LTM lenses would have to be limited to about 0.9 or 1 meter given that the LTM mount cameras were built to only couple up to 1 meter, right? While the M mount has 0.7 as the coupling limitation. I could be wrong.

The only LTM lens that I know of that doesn't have that is the ltm 21mm skopar, and maybe some few other other wide angles.
 
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