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

45 or 90 degree 100mm binoculars ?

  • Please log in to reply
21 replies to this topic

#1 kcb

kcb

    Messenger

  • -----
  • topic starter
  • Posts: 493
  • Joined: 18 Jul 2013

Posted 04 September 2017 - 12:11 AM

hi,

thinking of purchasing 100mm binoculars by altairastro, they have two models, one is 45 degree angle, one is 90 degree angle, which is the better angle for stargazing ,any preference ? thanks, kevin



#2 SMark

SMark

    Skylab

  • *****
  • Posts: 4,486
  • Joined: 29 Aug 2011
  • Loc: Atlanta, GA USA

Posted 04 September 2017 - 12:19 AM

I have 90° and wouldn't have it any other way. The best views are at zenith anyway, so why not make it more comfortable to actually view that way? Not that 45° would be impossible, as that certainly isn't the case. But I love my 90° APM, and when I move up to something larger, it will also be 90°. like-button.jpg


  • Jon Isaacs, Stellarfire, kcb and 1 other like this

#3 rockethead26

rockethead26

    Fly Me to the Moon

  • *****
  • Posts: 6,966
  • Joined: 21 Oct 2009
  • Loc: Northern Arizona, USA

Posted 04 September 2017 - 12:38 AM

45° if you want to use them both for astro and daytime use. 90° for astro only. My APM 100's are 90° just like SMark.


  • kcb likes this

#4 Astro Boy

Astro Boy

    Explorer 1

  • *****
  • Posts: 88
  • Joined: 15 Apr 2012
  • Loc: Lake Bathurst , NSW , Australia

Posted 04 September 2017 - 01:04 AM

Another vote for 90s the 45s are a pain in the neck ( literally ) when viewing at high altitudes
  • kcb likes this

#5 PETER DREW

PETER DREW

    Apollo

  • *****
  • Posts: 1,446
  • Joined: 31 May 2017

Posted 04 September 2017 - 03:48 AM

It's very much a personal preference decision. I would always go for 90 degrees regardless as I find 90 degree viewing terrestrially is still more comfortable than 45 degrees for astronomy.


  • Jon Isaacs, raal and kcb like this

#6 Jon Isaacs

Jon Isaacs

    ISS

  • *****
  • Posts: 87,439
  • Joined: 16 Jun 2004
  • Loc: San Diego and Boulevard, CA

Posted 04 September 2017 - 08:23 AM

45° if you want to use them both for astro and daytime use. 90° for astro only. My APM 100's are 90° just like SMark.

 

As far a comfort goes, 90 degrees is fine for terrestrial viewing.  For astronomy, 45 degrees is a pain in the neck...  

 

Jon


  • kcb likes this

#7 Allan Wade

Allan Wade

    Aurora

  • *****
  • Posts: 4,767
  • Joined: 27 Jan 2013
  • Loc: Newcastle, Australia

Posted 04 September 2017 - 08:29 AM

My experience is also that the 45 degree models become very painful, very quick for astro use. 90 degree is the way to go for astro observing.


  • kcb likes this

#8 paulsky

paulsky

    Apollo

  • -----
  • Posts: 1,441
  • Joined: 17 Feb 2004

Posted 04 September 2017 - 09:46 AM

Hello,
Long time used a giant of 100mm Miyauchi of 45º and from a certain altitude was very annoying and complicated to observe, for terrestrial very well .. but for astro ... mmmm !!
Regards,
Paul


  • kcb likes this

#9 Rich V.

Rich V.

    Fly Me to the Moon

  • *****
  • Posts: 7,331
  • Joined: 02 Jan 2005
  • Loc: Lake Tahoe area, Nevada

Posted 04 September 2017 - 10:27 AM

The fact is, many of us that currently have 45° BTs would have gladly purchased 90° models if they had been available at the time.  45° viewing was a way better alternative than straight-through designs at the time, so what was there to do?  

 

Unfortunately, a number of the early 90° models had diminished effective aperture and prism cutoff/vignette.  It was really only lately after APM came out with 90° versions of their BTs that we've had a choice.  I'm sure if they offered the 90° models originally, there would be far fewer 45° BTs out there now.

 

Rich


  • Mr. Bill, kcb and PETER DREW like this

#10 tropical

tropical

    Viking 1

  • *****
  • Posts: 678
  • Joined: 08 Jun 2014

Posted 04 September 2017 - 11:28 AM

No way I will buy a 45 deg BT binoculars.  Been there done that and it  was a painful experience. grin.gif


  • kcb likes this

#11 Mr. Bill

Mr. Bill

    Cosmos

  • *****
  • Posts: 9,791
  • Joined: 09 Feb 2005
  • Loc: Northeastern Cal

Posted 04 September 2017 - 12:01 PM

What helps when using 45 oculars is a tripod with elevation crank....I can easily get to 80 degrees.

 

OTOH, IF I buy the APM 82mm, it would be 90 degrees.


  • Rich V. and kcb like this

#12 junomike

junomike

    Hubble

  • *****
  • Moderators
  • Posts: 19,872
  • Joined: 07 Sep 2009
  • Loc: Ontario

Posted 04 September 2017 - 01:02 PM

Although I'd probably prefer the 90° I'm ok with the 45's as It allows me to view Zenith while only needing to look up at a 45° angle.

As Bill says, a Tripod with elevation cranks works wonderfully.  I use a Manfrotto 3251.


  • kcb likes this

#13 Mike Harvey

Mike Harvey

    Surveyor 1

  • *****
  • Posts: 1,551
  • Joined: 01 Mar 2004
  • Loc: Melbourne Beach, FL.

Posted 05 September 2017 - 02:06 AM

I bought the APM 100's with 45 degree prisms.

When I "moved up" to the 120's I bought the 90 degree model.

Even though I did (and do) have a cranking adjustable center post

(Manfrotto 161Bmk2), the 90 has proven much more comfortable and user-friendly.


  • Jon Isaacs and kcb like this

#14 lulz

lulz

    Vostok 1

  • -----
  • Posts: 105
  • Joined: 08 Aug 2016
  • Loc: Østfold, Norway

Posted 05 September 2017 - 04:14 AM

As I will probably have the same dilemma, come spring 2018, can anyone post a short video or some photos how it is to view with 90* BTs for daytime use? 



#15 edwincjones

edwincjones

    Close Enough

  • *****
  • Posts: 13,453
  • Joined: 10 Apr 2004

Posted 05 September 2017 - 08:31 AM

Hello,
Long time used a giant of 100mm Miyauchi of 45º and from a certain altitude was very annoying and complicated to observe, for terrestrial very well .. but for astro ... mmmm !!
Regards,
Paul

 

45*

 I have never understood the interest in 90*  

Both are difficult >75*

 

edj


  • kcb likes this

#16 Jon Isaacs

Jon Isaacs

    ISS

  • *****
  • Posts: 87,439
  • Joined: 16 Jun 2004
  • Loc: San Diego and Boulevard, CA

Posted 05 September 2017 - 11:23 AM

 

Hello,
Long time used a giant of 100mm Miyauchi of 45º and from a certain altitude was very annoying and complicated to observe, for terrestrial very well .. but for astro ... mmmm !!
Regards,
Paul

 

45*

 I have never understood the interest in 90*  

Both are difficult >75*

 

edj

 

 

Realistically, 90 degree focusers at 90 degrees are like 45 degree focusers at 45 degrees..

 

:shrug:

 

Jon



#17 Mr. Bill

Mr. Bill

    Cosmos

  • *****
  • Posts: 9,791
  • Joined: 09 Feb 2005
  • Loc: Northeastern Cal

Posted 05 September 2017 - 12:12 PM

No matter which you use, you have to deal with "Dobson's hole" while using an alti azimuth mount near zenith.

 

tongue2.gif


Edited by Mr. Bill, 05 September 2017 - 01:33 PM.

  • edwincjones and GamesForOne like this

#18 Gordon Rayner

Gordon Rayner

    Gemini

  • *****
  • Posts: 3,307
  • Joined: 24 Mar 2007

Posted 05 September 2017 - 07:46 PM

Unless the azimuth axis can be tilted, thus moving the azimuth axis  such that is points somewhere   other than the Zenith.   Pivoting backward below the azimuth bearing, or  by  shortening one or two tripod  legs.   Caution to  keep the center of mass of the binoc- mount -tripod    away from the limit at which a fallover is impending.

 

A safety rope could be tied to a   stake, a wall , an automobile bumper, etc.  


Edited by Gordon Rayner, 05 September 2017 - 07:48 PM.


#19 eklf

eklf

    Surveyor 1

  • *****
  • Posts: 1,915
  • Joined: 12 May 2007
  • Loc: Carrboro, NC

Posted 05 September 2017 - 09:04 PM

I was never comfortable with 45* for night use, although for terrestrial use it was quite enjoyable. 

 

Even with a tripod equipped with a crankable elevetor post I found them uncomfortabe to look though at any elevataion above 45 deg.  

Attached Thumbnails

  • gallery_26623_4073_1407449881_26438 (1).jpg
  • gallery_26623_4073_1407449882_26439.jpg

  • paulsky, Jon Isaacs, ThomasM and 1 other like this

#20 GamesForOne

GamesForOne

    Apollo

  • -----
  • Posts: 1,254
  • Joined: 29 Sep 2009
  • Loc: Knoxville, TN

Posted 05 September 2017 - 10:37 PM

The key for comfort for me with the 45 degree model is to have a tripod high enough that I can either stand or sit between extended legs to get under the binocular. This is fairly comfortable to me for 60 to 85 degrees elevation.

 

The problems I have with 90 degree models are:

 

1) I have to lean over to look through them for low elevation (e.g. Sco/Sag in the summer or Mon/Canis Major in the winter) targets and I spend a lot of time looking at such targets, and

 

2) when pointed vertically it is difficult to look through a zero power finder. It's like trying to crane your neck with a zero power finder on a dob pointed straight up. The position underneath the bino that I describe above with the 45 degree model is more conducive to finder use.

 

---

Michael Mc


  • Mr. Bill and kcb like this

#21 Keith g

Keith g

    Messenger

  • -----
  • Posts: 409
  • Joined: 13 Feb 2005
  • Loc: Waterford/Cavan Ireland

Posted 06 September 2017 - 05:32 AM

I have the 90 degree APM120's, I wouldn't have it any other way for astro. I find this angle is very comfortable.

 

K


  • kcb likes this

#22 edwincjones

edwincjones

    Close Enough

  • *****
  • Posts: 13,453
  • Joined: 10 Apr 2004

Posted 06 September 2017 - 06:17 AM

No matter which you use, you have to deal with "Dobson's hole" while using an alti azimuth mount near zenith.

 

tongue2.gif

 

 

always a difficult place to be

 

edj




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