Return to the Cloudy Nights Telescope Reviews home pageAstronomics discounts for Cloudy Nights members
· Get a Cloudy Nights T-Shirt · Submit a Review / Article

Click here if you are having trouble logging into the forums

Privacy Policy | Please read our Terms of Service | Signup and Troubleshooting FAQ | Problems? PM a Red or a Green Gu… uh, User

Equipment Discussions >> Eyepieces

Pages: 1
SchrödingersCat
sage
*****

Reged: 11/02/08

In Focus Specs for Recent Über Zooms
      #5567814 - 12/12/12 03:14 PM

I am having a hard time rounding up the required in focus distance for the recent Über Zooms:

Namely the Meopta 8-16 mm, the original Leica, and the Leica ASPH. Knowing this spec would help me decide which EP would fit my existing scopes. I would likely use the zoom with a 2" adapter to minimize in focus. Can anyone shed some light on this?


Post Extras: Print Post   Remind Me!   Notify Moderator  
Tamiji Homma
Carpal Tunnel
*****

Reged: 02/24/07

Loc: California, USA
Re: In Focus Specs for Recent Über Zooms new [Re: SchrödingersCat]
      #5567916 - 12/12/12 04:31 PM

Here is data point. They are all in 2" mode.

The first column is how far focuser drawtube is out from end of OTA (TSA 102S + Baader 2" Maxbright diagonal used).

You need 26.5mm (80.0-53.5) inward focus distance with Meopta Zoom than Ethos 13.

53.5mm Meopta 8-16 + APM 2" M42 adapter
57.0mm Leica ASPH + Startlight Instruments 2" adapter
64.0mm Ethos 17
80.0mm Ethos 13

Tammy


Post Extras: Print Post   Remind Me!   Notify Moderator  
SchrödingersCat
sage
*****

Reged: 11/02/08

Re: In Focus Specs for Recent Über Zooms new [Re: Tamiji Homma]
      #5567979 - 12/12/12 05:18 PM

Thanks Tamiji,

I guess the meopta is out. Does any one have the spec for the old Leica zoom?


Post Extras: Print Post   Remind Me!   Notify Moderator  
BradleyB
professor emeritus
****

Reged: 09/01/06

Loc: Olympia, WA
Re: In Focus Specs for Recent Über Zooms new [Re: SchrödingersCat]
      #5568445 - 12/12/12 11:15 PM

I find the shoulder of the focuser to be quite far out for the Ethos 13 when it's fully seated in a 2" holder.

With my Hyperion zoom the focuser is 30mm inward compared the E13 and 20mm inward for the Hyperion 31 in comparison to the E13. I find these eyepieces to be close to most other eyepieces I've had or tried. So if the Meopta is only 26.5mm closer than the E13 it will be similar to most eyepieces.

Brad


Post Extras: Print Post   Remind Me!   Notify Moderator  
andydj5xp
Pooh-Bah


Reged: 05/27/04

Loc: 52.269 N/10.571 E
Re: In Focus Specs for Recent Über Zooms new [Re: SchrödingersCat]
      #5568666 - 12/13/12 04:33 AM Attachment (9 downloads)

Quote:

Does any one have the spec for the old Leica zoom?




The Leica 22-7.3mm has its focal plane about 3mm inside the zoom's body which is 1.5mm less than the ASPH zoom (4.5mm). Consequently, the drawtube position mentioned by Tammy would be 58.5mm.

Andreas

As an edit: my DIY adapters do require less distance from the eyepiece shoulder to the focal plane. This would translate into 72.5mm for the ASPH zoom and 74mm for the 22-7.3mm zoom.

The distance "F" (see the TeleVue eyepiece specification table) is -7.5mm for the ASPH and -6mm for the 22-7.3mm with the 2" adapter.

Edited by andydj5xp (12/13/12 02:06 PM)


Post Extras: Print Post   Remind Me!   Notify Moderator  
SchrödingersCat
sage
*****

Reged: 11/02/08

Re: In Focus Specs for Recent Über Zooms new [Re: andydj5xp]
      #5573885 - 12/16/12 10:24 AM

Andreas,

Could you share how you created the DIY adapter?


Post Extras: Print Post   Remind Me!   Notify Moderator  
andydj5xp
Pooh-Bah


Reged: 05/27/04

Loc: 52.269 N/10.571 E
Re: In Focus Specs for Recent Über Zooms new [Re: SchrödingersCat]
      #5574006 - 12/16/12 11:32 AM

Quote:

Andreas,

Could you share how you created the DIY adapter?




Here you go: DIY adapter for Leica ASPH zoom

BTW, the outfocus distances of the drawtube are not (as stated above) 72.5mm (ASPH) and 74mm (22-7.3mm) but only 66.5mm (ASPH) and 68mm (22-7.3mm). Thus, they are more like the Ethos 17.

Just forgot to mention: if the adapter T2 #16 is intended for the Leica 22-7.3mm zoom then only the threaded holes are needed. The male T2 thread and the 37.8mm opening can stay.

Andreas

Edited by andydj5xp (12/16/12 01:57 PM)


Post Extras: Print Post   Remind Me!   Notify Moderator  
Pages: 1


Extra information
30 registered and 38 anonymous users are browsing this forum.

Moderator:  ausastronomer, Scott in NC, iceblaze 

Print Thread

Forum Permissions
      You cannot start new topics
      You cannot reply to topics
      HTML is disabled
      UBBCode is enabled


Thread views: 513

Jump to

CN Forums Home


Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics