Collimation repair Tasco No. 116 7x35 binoculars

geologist

geologist

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My dad's 70s era Tasco No. 116 7x35 porro prism binoculars have the left tube higher than the rifmght tube optically. It's bad enough that they are unusable.

They've always been good so they must have received a hit during my last house move.

There us a lot of sentimental value in them for me. Is there any way to repair it myself. There are no collimation adjustment screws on the binocs.

If they are not home repairable, can anyone suggest a lower mainland outfit who could repair them. Repair cost is not a big issue.

Any advice will be appreciated.
 
sometimes the collimation is through adjustment screws but more frequently it is two eccentric threaded rings that secure the objective lenses. First thing is to see if an objective lense assembly has been inadvertently unscrewed a bit.

Have to say that anytime I thought i was clever enough to do an adjustment myself ... I made it worse.
Better to get a pro to do it from my limited experience.

Do you hear any loose parts if you shake them gently? sometimes a prism can come loose and you may be able to (carefully) resecure it by removing the objective lense assembly ... or the ocular and top cover plate depending on which prism it is and how they are secured in the body.
 
I unscrewed the objective caps, neither were loose and don't see eccentric threaded rings just some black rings, slotted in two places.

There is nothing rattling around inside when I shake them so no obvious loose parts.

The left tube image is definitely higher than the right tube so I think it's a physical impact and a resulting misalignment.
 
failing the eccentric rings being used ... sometimes the tiny screws (if used for collimation) are covered with a tiny dab of black wax .. can be hard to find but judicious poking with a tiny screw driver may help locate it.
 
Did you try this ? > http s://www.youtube.com/watch?v=kygO9VhKxIM
If the binocs have any sort of 'cover' the adj screws are 'hidden' under that cover. It's worked for a couple sets of really old 'low=priced' 'noc for me. I had to cut the cover, it was glued on with a light adhesive that luckily didn't get too hard or snug.
 
I owned an inexpensive pair of Tasco 7x35 Bino’s back in the 70’s. They used to go out of whack if dropped, would be seeing a double image. I would unscrew the objective lens barrels and try resetting the prisms, they were held in by a bit of glue and a metal strap with a small screw on each end. I guess the glue let go and the only thing holding them was the metal strap with screws. Was trial and error but I could usually get them half assed usable but not perfect.
 
'Geologist' ... I assume you are a geologist... just a FWIW - I understand that many geologists spend a significant amount of time in helicopters. At one point I did as well and discovered that the vibration in the machines I was in (Kiowa's and Huey's) had a significant adverse effect on the various fasteners in some of the optical equipment I had with me.
 
AP said:
'Geologist' ... I assume you are a geologist... just a FWIW - I understand that many geologists spend a significant amount of time in helicopters. At one point I did as well and discovered that the vibration in the machines I was in (Kiowa's and Huey's) had a significant adverse effect on the various fasteners in some of the optical equipment I had with me.
Click to expand...

When I'm doing helicopter field work I just carry in my vest a Vortex 8x25 monocular to save weight.

This misalignment is recent after my house move. It got bonked.
 
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