Bushnell 13-1650 collimation is way off - how to adjust? (1 Viewer)

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Terry O'Nolley

Cow-headed Jaybird

• Aug 28, 2005

• #1

I recently purchased a pair of Bushnell 13-1650 binos from eBay.

A "no-no". But I had already tested that model and really enjoyed its solid feel, rubberized grip, 1 touch focusing lever and the 50mm apertures. So when I saw a pair advertised as pristine complete with case, strap and lens covers for $25 I bought them.

Woe is me! They are misaligned - I am seeing double.

Does anyone know how to make collimation adjustments on this model of binocular?

Thanks.

 

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Robert Ellis

Larus marinus

• Aug 28, 2005

• #2

It may be tough, I seem to remember that there was not much to the internals. If you can find where the set screws are on the housing (on on top one on bottom) you can try turning them, but the problem with a design this marginal is that the prisms may not ever go back into collimation long enough to enjoy them.

 

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Terry O'Nolley

Cow-headed Jaybird

• Aug 29, 2005

• #3

Robert Ellis said:

It may be tough, I seem to remember that there was not much to the internals. If you can find where the set screws are on the housing (on on top one on bottom) you can try turning them, but the problem with a design this marginal is that the prisms may not ever go back into collimation long enough to enjoy them.

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Any advice for which one to adjust? Or should I just determine which feels straighter and adjust the other one? I found where the rubberized covering can be peeled back - I am guessing the screws are under there somewhere but before I start turning, I'd like a little more advice.

Do you know how much a complete turn of the screw will change the alignment? Or is a complete turn like way too much? Or will it probably take 10 or 100 turns? I am completely clueless here. The good news is that if I hear something snap off and rattle around inside I am not out very much money.

 

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Robert Ellis

Larus marinus

• Aug 29, 2005

• #4

If you turn the top screw down (in, clockwise) the image on that side should go up. A primitive way to chec which side is closer to ideal is the impromptu "star test" which you can find well described in a recent thread, just do a search.

Vertical collimation is more important than horizontal, and about all one can do on their own the first try.

If you have to back a screw out the prism may not come with it, hence you will have to disregard which side is better and merely drop one side to match the lower-aimed side.

A binocular in that range was not designed to be recollimated over time as a basic maintenance as they were considered replaceable for nearly to cost of the work. My condolences if they can't be salvaged.

Oh, an eighth or quarter of a turn each time should suffice, small turn then a quick look, repeat.

 

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Terry O'Nolley

Cow-headed Jaybird

• Aug 30, 2005

• #5

I didn't find the screws where I thought they would be (under the rubber coating near the joint between the objective lens and the eyepiece) do you where to look for the screws?

 

xenophobe

Well-known member

• Aug 30, 2005

• #6

ebay is generally a safe place to buy. I've bought hundreds of items and have only been screwed over once completely. A few other items not as described, but that's generally not typical.

Contact the seller, inform him that the miscollamination was not as described, ask for a refund. If he doesn't, leave negative feedback and then send the unit back to the factory.

I hate ebay sellers that don't specify damage or problems. Most are willing to do something about it.

 

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Robert Ellis

Larus marinus

• Aug 30, 2005

• #7

Terry O'Nolley said:

I didn't find the screws where I thought they would be (under the rubber coating near the joint between the objective lens and the eyepiece) do you where to look for the screws?

Click to expand...

I don't know exactly where they eould be on your bin. Somewhere near the top edge on the main housing, possibly part way around to the side, if you follow.

 

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Terry O'Nolley

Cow-headed Jaybird

• Nov 27, 2005

• #8

I fixed it - the left lens was cross-threaded. I unscrewed it and cut away the bad threading and then carefully screwed the lens back in and now it works great.

 

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BenBirding

Well-known member

• Nov 28, 2005

• #9

Mine got misalligned in a fall. I beat the supports in the middle back straight with various tools, and bingo, back to normal.