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

APM binocular collimaton question?

  • Please log in to reply
7 replies to this topic

#1 adamsdp

adamsdp

    Vostok 1

  • -----
  • topic starter
  • Posts: 185
  • Joined: 18 Feb 2005

Posted 15 May 2019 - 03:53 PM

I have new APM 100 mm 90 deg ED binoculars and wondering how to check collimation and what are realistic expectations.  I had them out the other night and with Morpheus 6.5 mm eyepieces in place, if I pulled my eyes back around 4-6", I was seeing misaligned star images that were offset mostly in the vertical axis.  I randomly rotated the left Morpheus eyepiece about 60 deg in the eyepiece holder and rechecked and the alignment was much better.  Maybe the eyepiece barrel is not concentric?  I will try again on different targets and during the daytime as well.  I didn't notice any problems while observing normally but have read that misaligned binoculars can cause eyestrain and want to check these out while still under warranty.  Are there better ways to check the collimation than what I tried that can be done at home?

 

I have read that it might be better to collimate myself if I can get the APM collimation tool vs sending them back for collimation as they can be tuned to one's eyes and not sure if this true or not.  The other thing would be if they were sent for collimation, how likely are they to stay in alignment on the return shipping trip?  Thanks,

 

Dave

 

p.s.  Love the binoculars!  I was comparing them to my SV105 with binoviewer and really glad I took the plunge and bought the APM 100's.  It is what one would expect, but using the binoculars was a joy.  The fov was wider (about double) with the supplied 18mm eyepieces and stars were brighter than in the SV105/Denkmeier binoviewer/21mm Denkmeier eypeices/OCS/Powerswitch.  I greatly enjoyed the widefield image correct views and 18 mm and Morpheus 6.5 mm eyepieces are both very friendly to look through as far as eye position and relief.  The binoculars went deeper into star fields as one would think based on the telescope splitting the light into 2 images.  The moon looked great in both but a slightly more 3d effect in the binoculars.  The only edge I noticed in the SV105 was perhaps slightly less secondary color when viewing Polaris but not sure is this was due to the dimmer overall image or better color correction of the excellent LZOS lense in the SV105.  More than any other instrument I have looked through, the APM 100 ED 90 degree binoculars just seemed to get out of the way and give the experience of being immersed in space taking in the sights.



#2 Mark9473

Mark9473

    Voyager 1

  • *****
  • Posts: 11123
  • Joined: 21 Jul 2005
  • Loc: 51°N 4°E

Posted 15 May 2019 - 04:18 PM

Put that left eyepiece in your refractor (using a normal diagonal, not the binoviewer), and then rotate it to see if indeed the optical axis doesn't coincide with the mechanical axis. It's not uncommon; I've seen this in eyepieces. Use a barlow before the diagonal if you can.



#3 TOMDEY

TOMDEY

    Soyuz

  • -----
  • Posts: 3546
  • Joined: 10 Feb 2014
  • Loc: Springwater, NY

Posted 15 May 2019 - 04:53 PM

6.5mm is getting up there for magnification. And that hypersensitizes both collimation issues and also how the eyepieces seat. I have the same binos (APM 100mm-90o ED APO). Your reseating it and getting a change seems to indicate that is a big contributor. How it feels with your eyes at the exit pupils is ultimately what actually matters. The eyeps are most likely to seat properly if you put them in with these binos pointing horizontally.   Tom



#4 oldmanrick

oldmanrick

    Messenger

  • -----
  • Posts: 422
  • Joined: 30 Jul 2015
  • Loc: Western Montana, USA

Posted 15 May 2019 - 08:51 PM

Dave,

 

Some of my eyepieces do the same thing in my 45 degree 100mm Lunt's.  As Tom said, the higher power, the more noticeable any misalignment will be.  I have the alignment tool for mine, and was able to improve it a little, but sometimes it is still misaligned when I first put in a set of eyepieces.  It is usually easy to correct somewhat by rotating the eyepiece(s), as you experienced.  

 

Actually, I'm not sure if it's the eyepiece mechanical axis not being concentric with the optical axis, or just the way the eyepieces tighten up in the holders, or a little of both that causes the misalignment.  There is probably a bit of misalingment in the binoculars themselves too.

 

As Tom said, I also find that if I want to chuck in another set of eyepieces to look at something already in the fov that I don't want to lose, I get better alignment if I hold the eyepiece against the stop while tightening the holder, if the binoculars are pointed much above 45 degrees.

 

Glad you are liking those APM's!  There are wonderful views to be had.

 

P.S. I also have a pair of the 6.5 Morpheus, and like them a lot for brighter objects.  They aren't too bad for deep space either, as the sky looks much darker than with the 17.5 Morpheus.  Only drawback is the smaller fov.

 

Rick


Edited by oldmanrick, 16 May 2019 - 10:35 AM.


#5 adamsdp

adamsdp

    Vostok 1

  • -----
  • topic starter
  • Posts: 185
  • Joined: 18 Feb 2005

Posted 15 May 2019 - 09:21 PM

Thanks for the helpful replies!  I just came in from trying them again and seated the 6.5 mm eyepieces with the binoculars in the horizontal position and couldn't pick up any misalignment.  Nice to know the finer points of seating the eyepieces and what is acceptable. 

 

Rick, what do you think of the 6.5 Morpheus vs the 9 Morpheus?  I find I need to press my eye glasses against the rubber eyecups somewhat firmly to take in the whole field and the Morpheus 9's are listed as having more eye relief - 21 mm for the 9's vs 18.5 mm for the 6.5.  I am thinking of trying the 9's instead of the 6.5's.  I really like the supplied APM 18 mm eyepieces and want to run with 2 pairs for a while and wondering if the 9's might be a nicer general purpose eyepiece for mid-hi power viewing than the 6.5?   Thanks!


Edited by adamsdp, 15 May 2019 - 09:24 PM.


#6 MB_PL

MB_PL

    Vostok 1

  • -----
  • Posts: 156
  • Joined: 04 Jun 2008

Posted 16 May 2019 - 12:44 AM

I have three pairs of the Morpheus eyepieces (4.5, 6.5 and 9mm) as well as two pairs of the Vixen LVWs (13 and 22mm). The 9mm Morpheus has the best ergonomics of the lot. There's something magical in this eyepiece - it has the best combination of ER and AFOV and is just a joy to use. I highly recommend it. It gets more use than the 6.5mm.

#7 oldmanrick

oldmanrick

    Messenger

  • -----
  • Posts: 422
  • Joined: 30 Jul 2015
  • Loc: Western Montana, USA

Posted 16 May 2019 - 10:34 AM

Thanks for the helpful replies!  I just came in from trying them again and seated the 6.5 mm eyepieces with the binoculars in the horizontal position and couldn't pick up any misalignment.  Nice to know the finer points of seating the eyepieces and what is acceptable. 

 

Rick, what do you think of the 6.5 Morpheus vs the 9 Morpheus?  I find I need to press my eye glasses against the rubber eyecups somewhat firmly to take in the whole field and the Morpheus 9's are listed as having more eye relief - 21 mm for the 9's vs 18.5 mm for the 6.5.  I am thinking of trying the 9's instead of the 6.5's.  I really like the supplied APM 18 mm eyepieces and want to run with 2 pairs for a while and wondering if the 9's might be a nicer general purpose eyepiece for mid-hi power viewing than the 6.5?   Thanks!

Dave, I'm just the opposite of MB PL, in that I find I use the 6.5 more than I do the 9mm pairs.

 

I think this is due to the way I observe.  I often scan or locate a target with my 17.5 Morpheus, then if I want a closer/larger view, I go all the way to the 6.5's.  I also like the very dark sky background they provide vs. the 17.5's, and even the 9's.

 

They are both great eyepieces, but for me the 6.5's are ergonomically just a bit more comfortable.  YMMV.

 

I use the Baader threaded eyecup extenders that came with the eyepieces for all of my Morpheus eyepieces.  This allows more adjustment to a  comfortable eye relief distance, as you can thread the rings in or out to adjust the eyecup position.  I just wish the threads were a bit tighter so they didn't wiggle around and rattle, though.

 

I don't wear glasses when observing, since I can bring things to focus with the bino focusers.  For me, eye glasses are very uncomfortable for binocular viewing.  I do have some astigmatism, but choose to overlook that rather than fight with my glasses.  In your case, since your glasses need to press against the eyecups, you probably use the original eyecup mounting without the extension rings?  If not you might try that.

 

There are some additional eyecups that come with the Morpheus eyepieces, but I can't recall just how they are used, and can't find the instruction sheet at the moment.  If you have the instructions you may be able to find a way to get the eyecups a little closer the the eye lens.

 

No doubt the 9mm Morpheus are a bit more versatile, especially if you are only looking at two sets of eyepieces for your binoculars, and your other set is an 18mm.  Which ever FL you choose will be great and very useful.

 

Hope this helps, and Best of Luck!

 

Rick



#8 adamsdp

adamsdp

    Vostok 1

  • -----
  • topic starter
  • Posts: 185
  • Joined: 18 Feb 2005

Posted 16 May 2019 - 08:21 PM

Thanks for the feedback on eyepieces.  I ordered the Morpheus 9 mm and will try them vs the 6.5.  I am thinking I will mostly use the APM 18 mm when I go out with my lighter weight mount that doesn't have push to digital setting circles like my dm-6.  I have found the > 2 deg fov when using the 18mm eyepieces and correct orientated views make star field identification/hopping easy and enjoyable.  I am planning to use either the 9 or 6.5 as the main eyepieces when I go out for longer sessions where I take the dm-6 and setup the dsc/skycommander/skysafari/ipad.

 

I will try the other eyecups that came with the 6.5's to see if there is a way to get closer than folding down the ones that came on the eyepieces.  I read a long time ago somewhere that the eyepiece is 1/2 the telescope and grateful for the Morpheus recommendations from other threads as they seem very well suited for binocular use.

 

Dave




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