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Out of collimation?

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4 replies to this topic

#1 Shane1200

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Posted 15 September 2020 - 11:55 PM

When I adjust the Interpupillary Distance as close as possible I still see two images. Does this mean the binoculars are out of collimation?   I been using them as monocular by shutting my left eye. 



#2 DeanD

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Posted 16 September 2020 - 12:29 AM

The IPD should be adjusted so that you can comfortably see a full image in each eye with no vignetting. It will vary a bit if you have porro prism binos, depending how close you are focussing. The IPD will be slightly less for close focussing: eg. my IPD is around 62mm for close focus, but 66mm for infinity. You wont get fully over-lapping images for close viewing due to parallax, although you should see a singular circular image at infinity, with full overlapping of each image.  

 

However, you should always be able to join the images in the centre of the fov without any eye strain. If you can't, then the collimation is probably at fault.



#3 range88

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Posted 16 September 2020 - 02:02 AM

When I adjust the Interpupillary Distance as close as possible I still see two images. Does this mean the binoculars are out of collimation?   I been using them as monocular by shutting my left eye. 

At any place within IPD range, you should see one image.

You may see two circles when the object is close, but the overlapping area should still constitute one image.

Otherwise out of collimation.



#4 Shane1200

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Posted 16 September 2020 - 10:45 AM

I thought that it  may be collimation.  They were fine the first 2 or 3 three times I used them and then I didn't use them for a couple of months. That's when I started having the problem and by then they were out of warranty.  I started researching the model and I found that it's a common problem with this model. I should have done a little more research before purchasing them.   But I found a youtube video of how to collimate this model so I can fixed it now. I just wanted to make sure before I made any adjustments  it was a collimation problem.

 Thanks for the help.  



#5 bumm

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Posted 16 September 2020 - 12:01 PM

My left eye is out of collimation due to a long neglected cataract which isn't a really unusual problem, and I had to recollimate all my binoculars to compensate.  Fortunately, all of them are poro prism models, and all but one had the two external screws under the covering.  Just mounted 'em on a tripod and diddled the screws on the left side til I only saw one star.  The other pair were my old 1976 11x80's, and I had to get inside the prism housing for that one.  SO NICE having them all working for me again...

I put instructions with each pair for whoever eventually inherits them to put them back.

                                                                                                                                                                                  Marty




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