How to modify binoculars for closer focus? (1 Viewer)

[Deanc]

A technician who used to operate in my area (Santa Cruz) could modify binoculars for closer focus. He did this for my Zeiss Dialyts so they could then focus just 10 feet away. I used these binoculars heavily for many years and they worked perfectly. Then they were stolen. He performed the same task for a number of other birders here with great success. That was 30 years ago. Since then I've inherited another pair of Zeiss Dialyts but I cannot find the technician. Do you have suggestions?

 

[Elkhornsun]

The Pentax Papilio II 8.5x21 binoculars sell for $126 and what makes them remarkable is their ability to focus down to 19 inches. This makes them great for macro viewing of insects and flowers and amphibians.

 

[delia todd]

Hi Dean and a warm welcome to you from all the Staff and Moderators. I've moved your post to the Binoculars forum where more people with the right knowledge are more likely to see it.

I'm sure you will enjoy it here and I look forward to hearing your news.

 

[Maljunulo]

I think I’d buy a Papilio, rather than have someone tinker with a working instrument.

Just my opinion.

 

[dannat]

A technician who used to operate in my area (Santa Cruz) could modify binoculars for closer focus. He did this for my Zeiss Dialyts so they could then focus just 10 feet away. I used these binoculars heavily for many years and they worked perfectly. Then they were stolen. He performed the same task for a number of other birders here with great success. That was 30 years ago. Since then I've inherited another pair of Zeiss Dialyts but I cannot find the technician. Do you have suggestions?

you just need get the objectives moved outbound, sone binos have room 4 this, some don't

 

[jring]

Hi,

first of all, wecome to birdforum!

As has already been stated, the distance between objective and eyepiece needs to be increased a bit. How easily this can be done depends on the model and can be done by any optics technician. I woud suspect that the eyepieces were removed and a thin spacer ring was inserted before they were screwed back in.

The question if these will still reach infinity focus for you after the operation and if not, whether you care about that.
In general, this removes a bit of the bit of focus drive beyond infinity that manufacturers add for those with myopia to use binoculars without glasses...

Joachim

 

[Tringa45]

The distance between objectives and eyepieces on most modern roof prism binoculars is fixed, so focussing is achieved by shifting an internal focussing lens to alter the objective focal length and maintain the same desired focal plane.
In binoculars with +ve. focussing lenses, these would be shifted backwards from the other objective elements to achieve close focus and -ve. focussing lenses would be shifted forwards.
Although the range of movement is restricted it seems that on some binoculars it is possible to shift this range backwards and forwards, possibly to accommodate the requirements of different magnifications within a binocular family.
This was the case with the change from Leica BA to BN, where close focus was improved at the cost of focus overtravel.
My 8x56 SLC came from the factory with a close focus no better than 4,6 m (3,9 m spec.) but has at least 7 dioptres overtravel (5 dptr. spec.).

John

 

[pat mitchel]

I'd try contacting Cory Suddarth at Suddarth Optical Repair

Suddarth Optical Repair - Binocular Repair & Binocular Repair Near Me & Binocular Collimation Service & Binocular Cleaning & Binocular Restoration & Fix Double Vision Suddarth Optical Repair

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I have no first hand knowledge of the bino in question but looking at pics of a dialyt, it appears to have a focuser identical to a porro bino focuser and bridge. If the objectives are of similar layout with all the focusing accomplished by moving the eyepieces at the rear, it seems feasible to shift the objectives forward and (or) increase the rearward movement of the eyepieces by adjusting the engagement of the focusing shaft with the focuser. Pat

 

[pat mitchel]

I should add that baker marine and mountain optics are down the coast from you and well known in the optics repair trade they may offer some leads as to the modification.

Binocular Repair, Baker Marine - San Diego, Ca

We've specialized in binocular repair along the San Diego harbor since 1936. Authorized repair facility for both Fujinon - Fujifilm and Fraser-Optics. Baker Marine is also offer compass adjustment services and is a proud Ritchie compass repair center

www.bakermarineusa.com

Superior Scope & Binocular Repair Service by Mountain Optics

We service all brands & models of binoculars & scopes - Specializing in high-quality scope & binocular repair service & restoration of WW1 and WW2 models.

mountainoptics.com

good luck , Pat

 

[richard866945]

A technician who used to operate in my area (Santa Cruz) could modify binoculars for closer focus. He did this for my Zeiss Dialyts so they could then focus just 10 feet away. I used these binoculars heavily for many years and they worked perfectly. Then they were stolen. He performed the same task for a number of other birders here with great success. That was 30 years ago. Since then I've inherited another pair of Zeiss Dialyts but I cannot find the technician. Do you have suggestions?

The inner eyepiece tube/lenses can be modified a bit to bring the tube closer to the external eye lenses. Enough to make a difference without affecting the infinity focus ( for most people ).