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

EdgeHD 14 + Baader Maxbright II + Hyperion MarkIV Zoom

  • Please log in to reply
11 replies to this topic

#1 mikela

mikela

    Lift Off

  • -----
  • topic starter
  • Posts: 9
  • Joined: 26 Jul 2020
  • Loc: Los Angeles

Posted 24 September 2020 - 06:07 PM

Hi Folks,

 

I have an EdgeHD 14 and am interested in getting a binoviewer for it.  I have read quite a bit about the Maxbright II and also the Hyperion Zoom.  Before pulling the trigger, there is some unclear thinking on my part and I am hoping someone can assist me:

 

1.  Will this work with the Celestron .7x reducer?  I assume that it will given that the back focus is maintained with it in place.

2.  Which diagonal would be best?  I have Baader Click Stop visual back and the Celestron 2" diagonal.

3.  What other elements would I need to make this work?

4.  Would the 1.8x GPC be a beneficial addition?  If so, where would it be placed?  OK, disregard, I just read that this can't be used with an EdgeHD.

 

There are a number of options when purchasing this binoviewer including nose pieces etc.  I am unclear which option would be best.

 

Thanks,

Mike


Edited by mikela, 24 September 2020 - 11:21 PM.


#2 Jethro7

Jethro7

    Apollo

  • *****
  • Posts: 1,295
  • Joined: 17 Dec 2018
  • Loc: N.W. Florida

Posted 24 September 2020 - 06:13 PM

Hello Mike, 

thanks for asking the questions. I have the same game plan I know these will work on my Frac but was wondering how to work this set up on my Edge HD. We will see what the responses go.

 

HAPPY SKIES TO YOU AND KEEP LOOKING UP Jethro


  • mikela likes this

#3 TG

TG

    Mercury-Atlas

  • *****
  • Posts: 2,617
  • Joined: 02 Nov 2006
  • Loc: Latitude 47

Posted 25 September 2020 - 01:28 AM

Actually I found that the main problems with Baader zooms and binoviewers was fitting my nose in between. I just made it by removing the eyecups.

#4 Eddgie

Eddgie

    ISS

  • *****
  • Posts: 27,202
  • Joined: 01 Feb 2006

Posted 25 September 2020 - 07:49 AM

I do not have a ray trace for the EdgeHD 14" but based on my experience with the standard C14, it is unlikely that the telescope will work at full aperture with your configuration (Clicklock, 2" diagonal, Binoviewer) but aperture reduction should be minor, so maybe something like 13.8 inches.

 

With a reducer (if you can reach focus) I would expect closer to 13.3".  Now that only matters if it matters to you.  That is not a lot of aperture loss on a C14. 

 

More serious would be the spherical aberration change.  I would expect on the order of 1/4rd wave.  Again, this is not a super big deal for general observing.

 

For planetary observing though, I would recommend that you use a powerful GPC to restore the aperture and correct the SA. I recommend the Televue Bino Vue 2x in this case.  You can set up the Binoviewer with a T2 quick connector to make going back and forth to the Televue amplifier easier (you would need quick connectors on both the amplifier and your 2" nose piece).

If it were a standard C14, focal length would go up by about 330m

 

There is no ray trace documentation avialable for the EdgeHD 14 so we can only extrapolate from the ray traces for the standard C14 and since no one has actually measured these things on the EdgeHD, please treat these as what they are, which is just extrapolations from my ray traces and my own experience with the standard EdgeHD 8" (which behaved a it worse than the standard C8 when used with binoviewers, but only al little, and the EdgeHD 8 is clearly quite a bit different than the standard C8 but the other EdgeHDs seem to be more similar to their standard counterparts). 


  • mikela likes this

#5 mikela

mikela

    Lift Off

  • -----
  • topic starter
  • Posts: 9
  • Joined: 26 Jul 2020
  • Loc: Los Angeles

Posted 25 September 2020 - 03:23 PM

Hi Eddgie,

 

If I understand correctly, my best option would be to get the BV with the 1.25 GPC and 2" nosepiece for low magnification or general viewing.  I assume at low magnification the 1.25 GPC would be useful for correcting CA and slightly restoring the aperture?  For high magnification, a Televue 2x with the 2" nosepiece and T2 quick connect for planetary viewing.  Is this the Televue part (BVP-2001)?  Is this the T2 quick connect?

 

Based on your comments, it seems I may be in unchartered waters.  lol.gif

 

Thanks for your assistance...greatly appreciated,

Mike 


Edited by mikela, 26 September 2020 - 01:35 AM.


#6 noisejammer

noisejammer

    Fish Slapper

  • *****
  • Posts: 3,922
  • Joined: 16 Sep 2007
  • Loc: The Uncanny Valley

Posted 27 September 2020 - 03:11 AM

I routinely use my binoviewers at f/7, so that's not a huge issue, but you may run into a problem with spherical aberration caused by a long optical path between the reducer and the eyepiece. The trick may be to minimise the distance following your reducer.

 

I can't speak directly to the EdgeHD reducer but (the late) Ted Agos developed a simple barrel that allowed the optics for a f/6.3 reducer to be inserted into the nosepiece of a 1990's SCT imaging train. This reduced the distance between the reducer and focal plane by about 2". The website seems to have gone but some of Ted's test results are here.

 

It struck me that something similar could be done with the nosepiece of your diagonal. You would need to dismantle your EdgeHD reducer and measure the spacing for the various elements then fabricate a suitable holder with a 2" OD. It would be smart to make the exhaust port a T2 (M42x0.75) because this could screw directly onto a prism diagonal.

 

I'd then purchase a Baader 01B (T2, Zeiss spec) prism to use as a diagonal. I use mine at f/7 and slower so you should be fine with chromatic aberration. This would use the modified reducer as a nose piece which would locate your focal plane an almost ideal 115mm behind the reducer.

 

If the elements can't fit into a 2" tube with sufficient clearance, you could remove the 3.25" visual back (I assume the C14 HD has one) and work from there.


  • mikela likes this

#7 mikela

mikela

    Lift Off

  • -----
  • topic starter
  • Posts: 9
  • Joined: 26 Jul 2020
  • Loc: Los Angeles

Posted 27 September 2020 - 02:18 PM

I routinely use my binoviewers at f/7, so that's not a huge issue, but you may run into a problem with spherical aberration caused by a long optical path between the reducer and the eyepiece. The trick may be to minimise the distance following your reducer.

 

I can't speak directly to the EdgeHD reducer but (the late) Ted Agos developed a simple barrel that allowed the optics for a f/6.3 reducer to be inserted into the nosepiece of a 1990's SCT imaging train. This reduced the distance between the reducer and focal plane by about 2". The website seems to have gone but some of Ted's test results are here.

 

It struck me that something similar could be done with the nosepiece of your diagonal. You would need to dismantle your EdgeHD reducer and measure the spacing for the various elements then fabricate a suitable holder with a 2" OD. It would be smart to make the exhaust port a T2 (M42x0.75) because this could screw directly onto a prism diagonal.

 

I'd then purchase a Baader 01B (T2, Zeiss spec) prism to use as a diagonal. I use mine at f/7 and slower so you should be fine with chromatic aberration. This would use the modified reducer as a nose piece which would locate your focal plane an almost ideal 115mm behind the reducer.

 

If the elements can't fit into a 2" tube with sufficient clearance, you could remove the 3.25" visual back (I assume the C14 HD has one) and work from there.

Given the effect on aperture cited in Eddgie's post, I believe you are right.  I think the Baader T-2 01B prism diagonal which has a FL of 38.5mm might work.  Also found this in the bino manual "Most Schmidt-Cassegrain and Maksutov telescopes provide large amounts of back-focus due to their movable primary mirror. It may be possible to use a binoviewer without a compensator, though our 1,25x Glasspath Corrector is recommended for its colour correction and to keep the focal length of the telescope closer to its optimal design." So it looks like the 1.25x GPC will reduce another 17mm and also correct the CA.  Either the Baader T Adapter (16mm) or the Ultra Short T Adapter (7mm) in lieu of the ClickLock would provide further reduction on the stock VB or .7x Reducer.  Does this sound like it would work?


Edited by mikela, 27 September 2020 - 04:05 PM.


#8 noisejammer

noisejammer

    Fish Slapper

  • *****
  • Posts: 3,922
  • Joined: 16 Sep 2007
  • Loc: The Uncanny Valley

Posted 27 September 2020 - 11:08 PM

It's almost certain that you'll be able to achieve focus whatever you do; the trick lies in optimising the light path so that you don't compromise image quality.

 

I have Baader Clicklocks on all of my scopes & they handle the torque from a binoviewer + heavy eyepieces (like Delos) really well. If possible, I recommend you keep it. Using a Ted Agos (like) reducer effectively places the reducer inside the Clicklock. This means the reducer is in the correct location relative to the C14 optics and you still preserve the mechanical benefit of the Clicklock.

 

The optical path length of my 01B prism, the quick release and my MkV binoviewers is about 135 mm. I believe the MB2 is a little shorter and if you omit the quick release, you could be around 120mm. This would be close to the ideal distance relative to your reducer and thus you'll obtain optimal performance.

 

On the glass path corrector - I use the 1.25x & 1.7x but my primary scope has a focal length of 1100 mm. I don't use either when I'm after a wide field. I'm sure there's some image degradation but at 31x or 36x or 42x (35mm, 30mm & 26mm resp), I can't see it.


  • mikela likes this

#9 noisejammer

noisejammer

    Fish Slapper

  • *****
  • Posts: 3,922
  • Joined: 16 Sep 2007
  • Loc: The Uncanny Valley

Posted 27 September 2020 - 11:21 PM

As an edit, you may find the Optec Lepus works better than the Celestron reducer. It appears to be designed along the lines of Ted's reducer - https://optecinc.com...lepus/index.htm.

 

Here's one dedicated to the C14 EdgeHD.

 

Another option might be to use a refractor's reducer. I'd recommend having a chat with Optec before committing my pennies.


  • mikela likes this

#10 mikela

mikela

    Lift Off

  • -----
  • topic starter
  • Posts: 9
  • Joined: 26 Jul 2020
  • Loc: Los Angeles

Posted 27 September 2020 - 11:42 PM

Thanks for the advice...much appreciated.  I think I will try things out first with the ClickLock and see how things go. The Lepus looks interesting and looks like it would work with the ClickLock.  I'll do some more research on it.



#11 mikela

mikela

    Lift Off

  • -----
  • topic starter
  • Posts: 9
  • Joined: 26 Jul 2020
  • Loc: Los Angeles

Posted 01 October 2020 - 02:58 PM

As an edit, you may find the Optec Lepus works better than the Celestron reducer. It appears to be designed along the lines of Ted's reducer - https://optecinc.com...lepus/index.htm.

 

Here's one dedicated to the C14 EdgeHD.

 

Another option might be to use a refractor's reducer. I'd recommend having a chat with Optec before committing my pennies.

I called Optec and they indicated that this is intended for astrophotography only.  It has a limited back focus of 100mm.

 

In any case, I have ordered the MBII, T2 01B prism and Hyperion zoom EPs.  Hopefully there will be new shipments soon.


Edited by mikela, 01 October 2020 - 02:58 PM.


#12 noisejammer

noisejammer

    Fish Slapper

  • *****
  • Posts: 3,922
  • Joined: 16 Sep 2007
  • Loc: The Uncanny Valley

Posted 01 October 2020 - 03:13 PM

Good luck with your adventure!

 

Re the Optec reducer - you could try installing one between a 2" diagonal and the binoviewers - this requires a light path of little more than 100mm and should work fine.




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