TheSkySearchers

Hi all...first time poster and newbie (please excuse my jargon in the post). Just moved to dark sky area and was thrilled to unpack a pair of Skymaster 25x100's I bought based on some reviews. The problem is that the way the eyepieces are set, the only way I can see anything is to close the binoculars all the way up, making it impossible to get my eyes to the eyepieces. This can't be right, can it? I have normal sized head and no one has ever said that eyes are freakishly close together. Any thought? I'm thinking to return these. Other recs? PS - I went with binoculars over a telescope based opinions that this is good way to get into astronomy.

thanks!

Mark

Hi Mark and Welcome to TSS!

Have you mounted the binos on a tripod?

Also, if you can post a photo that may help folks diagnose the problem.

Here's a quick review of the 25x100's.

https://www.astronomytrek.com/celestron ... rs-review/

A google search didn't lead to any insights on the problem you describe

Hi Mark,

I own these binos. First off, you need to know that the distance between your pupils is called your interpupillary distance or IPD. I have a fairly narrow IPD and and can still use these binos easily. These binos do allow for a normal amount of adjustment based on your IPD.

Let's start with the easiest fix first, have you tried flipping the binoculars over so that the bottom side becomes the top and vice versa.

These binoculars are so heavy they absolutely require some form of support; a tripod is the minimum needed for these binoculars, better yet a parallelogram mount.

Let us know how you fare.

Cheers

Hi Mark, thanks for joining TSS.

I am wondering if they maybe out of collimation.
Do you a slight "double image"?

Also look through each tube with your dominant eye, that will check the optics.

Thanks for the replies!

1. I do have a tripod that I bought on the recommendation of the vendor. I tried turning them upside down (clever!). No go.

2. Looking through each tube the image is fine, but to use them with both eyes and have the images get close to merging, I need to squeeze them all the way closed. That's the problem. The eyepieces are so close together that my nose doesn't fit at all between them, so my eyes are far away from the eyepieces. Here's a pic of how I need to set the binoculars to use them at all . Also see attached is link doesn't work

3. My IPD is 59, slightly below average (63). Given this, it seems unlikely that I should have to make the distance between the eyepieces as narrow as the binoculars will go.

Given all this info, are these defective? Is it something with me? Thanks.

They are not defective per se. They are simply out of alignment. Some binoculars require that you "collimate" the optical axis of one side of the binocular against the other so that your brain can assemble the images.

I have two pair of Celestron binoculars, I have their 15x70 and the 25x100. The 15x70s came to me in the same condition as your 25x100. I sent them back. Although it is a crapshoot because the replacement pair could exhibit the same problem. I have yet to see if the 25x100 have the ability to be collimated. It typically means you have to peel back the black covering to reveal set screws that position the prisms in the binoculars.

There are several good articles on the internet on how to collimate your binoculars. This is probably your next step. Or you could send them back and hope the replacement pair is better.

Cheers

Thanks JT and everyone. I will send them back and hope that the next pair are properly calibrated. I found an article that describes how. Doesn't seem that hard, but it would be much better if they just worked out of the box.

Mark

QC on Skymaster 15x70s is a well known problem (I had two different pair), but I've not read many complaints about 25x100s.

Hello Mark and welcome to the Forum.

I hope you have better luck with a replacement pair of binoculars.