Collimating Helios Quantum 5.2 Binocular Telecsope

[bond19]

Hi Stargazers,

My Helios Quantum 5.2 binocular telescope recently took a fall. I sent them off for repairs as the eyepieces were damaged but they have come back out of collimation. Is there a way for me to collimate them at home?

 Thanks in advance,

Edited November 4, 2021 by bond19

[BinocularSky]

Short answer: I'm not sure; haven't actually had my grubby mitts on one of these.

Long answer: Most binoculars of this type are collimated with eccentric rings on the objectives. you usually need to undo a retaining ring to get access to the eccentrics. You will need a lens tool (sometimes aka adjustable peg spanner) - beware, the common ones are just slightly too small for a 100mm objective. The way I do it is to use Polaris and defocus one side so it's a blob, then tweak the rings until the pinpoint star from one side is in the centre of the blob from the other.

BUT

Given that they've been dropped damaging the eyepieces, it is likely that the cause of miscollimation is not the objective lenses, but a prism. This is much less easy to remedy. If you decide to get it done professionally, the place I'd go to is OptRep https://www.opticalrepairs.com/

I hope that helps.

[bond19]

Thanks. I think it would be out of my skill set. I thought I’d ask anyway. I appreciate your reply

[Merlin]

Using the rings is known as conditional collimating, not true collimation.

[BinocularSky]

12 hours ago, Merlin said:

Using the rings is known as conditional collimating, not true collimation.

Not so. Conditional alignment is the case when the optical axes are parallel at a particular IPD but are not parallel to the hinge, so do not remain parallel if you alter the IPD. The Q5.2 does not have a hinge, therefore there is no hinge to which you can get the optical axes parallel. In that format of binocular, the eccentric ring convention is usually the only way of collimating it.

In general, the eccentric ring convention is more reliable than the prism-tilt convention (especially the "through  the body" prism tilt seen on most low-cost binoculars).

For more detail, read Bill Cook's "Understanding and Attaining 3-Axis Binocular Collimation" (it was Bill who coined the term "conditional alignment").

Edited November 8, 2021 by BinocularSky
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