Opticron Oregon 15 x 70 Collimation?

[Steve2112]

Hello,

With the darkening nights I retrieved my Opticron Oregon 15 x 70 binoculars from their safe summer storage (top of bookcase). Alas I am now seeing double stars and planets (the moon is fine and also distant views during daylight) which I understand is a collimation issue. Searching questions have been asked and no-ones admitting to dropping them/rough handling during their bookcase perching. I have contacted Opticron who are quoting £50 plus . I'm hesitant to pay that (I live north Of The Highland Line so additional postage can be added) in case my pair are prone to collimation problems. My question is has anyone carried out collimation on Opticron 15 x 70 and can tell me where the adjusting screws are (the entire body is covered in rubber). I have no problems havng a go, at the moment they are no good for astronomy, unless I cover up one lens (then I've got a telescope). Any guidance would be appreciated.

[John]

Hello and welcome to the forum.

I think the recent Opticron Oregon's are similar to the Celestron Skymasters so this might help:

http://binocularreviews.northernoptics.co.uk/optic-hints-and-tips/how-to-collimate-celestron-skymaster-15x70-binoculars/

And also this for another version of these binoculars:

https://oberwerk.com/collimation-instructionsfor-lw-series-and-mariner-series/

Edited August 27, 2021 by John

[Steve2112]

John, thank you for your response and the two links, very much appreciated. As you say the Opticron adjusting screws are in the same location. I'll give it a go tonight.

[BinocularSky]

I find the easiest way to get it close is to focus on Polaris, then defocus the right eyepiece. This prevents your brain from trying to merge the images, which it can do if they are slightly out, but this can introduce headaches or nausea). (Other brain-fooling methods include anaglyph glasses - or different coloured cellophane sweet wrappers - and crossed Bahtinov masks.) Then tweak the collimation screws until the focused point is in the middle of the defocused blob. Note that (as with the other advice above), this does not result in full collimation, but in conditional alignment, the condition being the interpupllary distance - if you change it, you can introduce a double image again. This is because you are making the optical axes of the tubes parallel, but they  will almost certainly not be parallel to the hinge.

 

[Steve2112]

Thank you, will try this as well. As is my luck, every night has been cloudy so far - time we got rid of this blocking high pressure system.