Jump to content

  •  

CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.

Photo

Can Orion 2x54 be collimated?

  • Please log in to reply
8 replies to this topic

#1 Ryan O'Connell

Ryan O'Connell

    Lift Off

  • -----
  • topic starter
  • Posts: 13
  • Joined: 11 Jul 2017
  • Loc: Portland, OR

Posted 30 May 2021 - 05:53 AM

I love these but they are just a bit misaligned. Can they be collimated? I remember hearing that some binos have eccentrically mounted objective lenses that can be rotated for collimation, but I have no idea what idea what I’m talking about. 

Attached Thumbnails

  • EFB19552-953B-4694-BF68-7042AD854372.jpeg
  • 3473E38D-C2A7-4906-B029-84F15066B5B5.jpeg
  • 63EA739C-6DBB-460C-94AF-FA5D9C136A81.jpeg
  • 05CEC019-96B1-4B8B-8FDA-F88D6E22E2C3.jpeg


#2 MartinPond

MartinPond

    Fly Me to the Moon

  • *****
  • Posts: 6,384
  • Joined: 16 Sep 2014

Posted 30 May 2021 - 07:10 AM

They are Galilean....

the direction of your view depends mostly on where your eyes are at.

 

Hold them away from your face a few inches and adjust that IPD hinge until the

    images merge.   That should help when you move them back towards your eyes.

    That is needed sometimes with adjustable opera glasses. 

 

At a power of 2X, it's hard for your eyes to get out of sync from each other,

   unless something is bent or the lenses are skewed (not held in flat).

 

Eccentrics would have no chance, BTW..     


Edited by MartinPond, 30 May 2021 - 07:12 AM.


#3 PEterW

PEterW

    Mercury-Atlas

  • *****
  • Posts: 2,669
  • Joined: 02 Jan 2006
  • Loc: SW London, UK

Posted 30 May 2021 - 08:29 AM

I held two camera multipliers to my eyes and your brain is pretty good at merging them, takes quite a bit to misalign. I just stuck the camera multipliers into a printed housing with no care about dine aligning. I hope yours haven’t sustained a bash? Did they work before?

PEter

#4 TOMDEY

TOMDEY

    Voyager 1

  • *****
  • Posts: 10,190
  • Joined: 10 Feb 2014
  • Loc: Springwater, NY

Posted 30 May 2021 - 08:56 AM

Agreeing with Martin here. The object-space optomechanical "collimation tolerance" on any binoscope is proportional to magnification. On a 2x that is a barn door and extremely unlikely to be off. It's far more likely that you either have the IPD or focus maladjusted or that you have undiagnosed/uncorrected differential prism in your eyes. It's also possible that eyeglasses will screw up the prismatic interaction with binos. So try those things first.

 

Next thing (really for anyone, problems or not) is to at least have your full-service optometrist check your prismatic differential. They usually won't do that unless you specifically ask. We all have some; it's just a question of whether it's significant enough to cause eye strain or vergence problems. Bill Cook reminds us that these are called dipvergence, divergence and convergence on the instrument side of the equation with tolerances of two, two and four arc-min when collimating binos. On the eye side the prismatic correction units are expressed in degrees.

 

One way to self-check for prism is to relax and fixate on some distant structured object. Use your hand to block one eye than the other in rapid succession while fixated on that object. If it jumps in position systematically, that is your prism. e.g. my right eye sees things a few arc-min higher and to the left. I comfortably comp that both eyes open and not drunk... but there it is. Like I said, everyone has at least a bit of that, but too much would require corrective eyewear or some eye repair.

 

With the CoVid stuff, most people have neglected their annual eye exam... me included. I'll make an appointment today.    Tom

Attached Thumbnails

  • 125 binocular alignment tolerances bill cook.jpg

  • ihf likes this

#5 Ryan O'Connell

Ryan O'Connell

    Lift Off

  • -----
  • topic starter
  • Posts: 13
  • Joined: 11 Jul 2017
  • Loc: Portland, OR

Posted 30 May 2021 - 11:26 PM

Thanks everyone for the detailed answers. I see that the prism column on my last prescription is blank, so I’ll have to get that checked. Pupillarily (new word, you’re welcome) speaking, I can say that I used binos and NVGs for years in the military and never had a problem finding the right IPD adjustment. Prism-wise, it is definitely possible that my eyes are out of whack now, as they’ve gotten worse in the 5 years since I retired despite having passed flight physicals for years.

 

The last pair of binos I used was a jumbo pair from Orion that I bought for my dad to put on his back deck. These actually did need collimation, and I figured out how to locate the hex screws, adjusted the prisms, and my peepers were apparently okay then because everything lined up. 
 

Edit: And btw, I haven’t tried wearing glasses when using binos or telescopes. Recently purchased a 0.75 astigmatism corrector from Televue to go over an eyepiece, but that’s a different story. 


Edited by Ryan O'Connell, 30 May 2021 - 11:30 PM.


#6 gwd

gwd

    Mariner 2

  • -----
  • Posts: 240
  • Joined: 27 Aug 2011
  • Loc: PyeongTaek ROK

Posted 16 July 2021 - 12:07 AM

I got these 2x54s because of all the chatter here on CN.  I also feel like they aren't collimated.   It feels like my eyes are accommodating as I change between naked eye and these.    Mine also don't give me a 36 degree field of view.  Last night I had them out under the stars for the first time.   When I got Cygnus in the field of view, Deneb at one edge and Albireo on the other were both blurry.    That is more like a 22 degree usable field of view isn't it?   Are you guys getting a 36 degree view?  With the murk and light pollution here they really help display the constellations.  



#7 PEterW

PEterW

    Mercury-Atlas

  • *****
  • Posts: 2,669
  • Joined: 02 Jan 2006
  • Loc: SW London, UK

Posted 16 July 2021 - 01:21 AM

You *can* get close to 36degrees with careful use and choice of bright stars. You want to place the stars horizontally across the field of view and stare straight ahead and rely on averted vision to detect the distorted fuzzy stars. Not a fully useful field that wide, but they’re wider than most of the others that are on the market and do what they’re intended to.

Peter

#8 spazmore

spazmore

    Genial Procrastinator

  • *****
  • Moderators
  • Posts: 2,102
  • Joined: 30 Aug 2008
  • Loc: Clinton, TN

Posted 16 July 2021 - 08:41 AM

I also feel like they aren't collimated.

I have a pair as well, and feel the same; you can focus on a point in space/the distance, then move them away from your eyes about 1', and clearly see that the point that you're focused on (a star, a light, a tower) is shifted in one eyepiece vs. the other; at infinity, they should be in the same location in the FOV. At times, this is bothersome to me, other times, it barely noticeable, and I have 4 pairs of the Tento 2.3x40s and a Kinglux 2.5x42 to compare them to. The Orions are definitely out of alignment. If I forcefully twist the two halves in opposite directions when viewing, it immediately takes the eye strain away, but it returns when I let go; it requires a good deal of twisting force to do this, so it's not an easily maintainable viewing arrangement.

 

The screws shown in the pics above don't affect collimation, but they do break easily, even with a correctly sized flathead screwdriver. The single one on the brass colored/eyepiece size immediately had 1/2 of the head snap off, and one of the ones on the black tripod mount stalk broke as well. So be warned.

 

I'll look later to see if there is some eccentric adjustment; hopefully, there is. I'll report back if I find that this is the case.



#9 Jon Isaacs

Jon Isaacs

    ISS

  • *****
  • Posts: 94,651
  • Joined: 16 Jun 2004
  • Loc: San Diego and Boulevard, CA

Posted 18 July 2021 - 05:36 AM

Thanks everyone for the detailed answers. I see that the prism column on my last prescription is blank, so I’ll have to get that checked. Pupillarily (new word, you’re welcome) speaking, I can say that I used binos and NVGs for years in the military and never had a problem finding the right IPD adjustment. Prism-wise, it is definitely possible that my eyes are out of whack now, as they’ve gotten worse in the 5 years since I retired despite having passed flight physicals for years.

 

 

I think others have made the point that these are Galilean's and therefore different in some respects than traditional binoculars. In a traditional binocular or telescope, there's a visible exit pupil that defines the center of the field as well as the field of view. 

 

I believe this is not the case with Galelean optics, the center of the field depends how you look through the binoculars.

 

Jon


  • KennyJ likes this


CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.


Recent Topics






Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics