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

Vixen flip Mirror which helical focuser works and can thread on the body?

  • Please log in to reply
5 replies to this topic

#1 markm75c

markm75c

    Viking 1

  • *****
  • topic starter
  • Posts: 893
  • Joined: 17 Sep 2009
  • Loc: Pittsburgh, PA

Posted 18 September 2020 - 08:01 PM

So at this point I have the vixen.  I've found that focus is just slightly off, even with the barlow/powermate going on the scope side.  I thought folks were using a helical focuser to work around this.

 

So i've tried this focuser:

 

svbony: https://www.amazon.c...0?ie=UTF8&psc=1

 

I tried both with and without that 2" adapter, the threads on the bottom are male but no adapter i had on hand would work on the vixen side (directly without the holder in place) or even to slide into the 1.25" eyepiece holder.

 

So it seems either the mysterious adapter that can go from that svbony to the vixen base thread, or some other type of helical focuser that can slide in like an eyepiece would be the ticket, i just cant find anything or i'm not looking for the right things.  I think the male threads on the focuser i have now are (M42*0.75 male thread needs to convert to female of the vixen size which i forget T2 or similar)

 

Anyone have any info here

 

EDIT: i think the easiest solution is the 1.25" slide in type, and there arent many, like this ebtools version for $42 here

 

 

Thanks in advance


Edited by markm75c, 18 September 2020 - 08:06 PM.


#2 johnpd

johnpd

    Viking 1

  • -----
  • Posts: 902
  • Joined: 12 Apr 2008
  • Loc: Green Valley, AZ

Posted 19 September 2020 - 08:49 AM

I don't quite get what you are trying to do.

 

1) The Vixen flip mirror has a 2" barrel to insert into the telescope focuser. Each of the ports has a T2 (M42) male connector to which you can screw in the 1.25" eyepiece holders, cameras with T2 connections, or other adapters/devices with T2 female connections.

 

2) What telescope do you have the Vixen flip mirror attached to? I assume it has a 2" focuser. What is the range of the focuser (in mm)

 

3) You said that you cannot achieve focus. Is this with normal visual viewing or imaging? Is this only happening with a barlow? Is the Powermate 2"?

 

4) Is the problem that you cannot focus in far enough or out far enough? I have tried two barlows (1.25" @ 2.5x and 3x) for imaging. Both focus inside of what I would use for normal viewing. If you are using a camera, what camera?

 

As far as an adapter similar to what you had, I got this one: (SVBONY SV151). I have not really needed it however.

 

JohnD



#3 markm75c

markm75c

    Viking 1

  • *****
  • topic starter
  • Posts: 893
  • Joined: 17 Sep 2009
  • Loc: Pittsburgh, PA

Posted 19 September 2020 - 05:24 PM

I don't quite get what you are trying to do.

 

1) The Vixen flip mirror has a 2" barrel to insert into the telescope focuser. Each of the ports has a T2 (M42) male connector to which you can screw in the 1.25" eyepiece holders, cameras with T2 connections, or other adapters/devices with T2 female connections.

 

2) What telescope do you have the Vixen flip mirror attached to? I assume it has a 2" focuser. What is the range of the focuser (in mm)

 

3) You said that you cannot achieve focus. Is this with normal visual viewing or imaging? Is this only happening with a barlow? Is the Powermate 2"?

 

4) Is the problem that you cannot focus in far enough or out far enough? I have tried two barlows (1.25" @ 2.5x and 3x) for imaging. Both focus inside of what I would use for normal viewing. If you are using a camera, what camera?

 

As far as an adapter similar to what you had, I got this one: (SVBONY SV151). I have not really needed it however.

 

JohnD

i'm referring to the eyepiece port on the vixen.  Yeah its the T2 M42 that was the issue because the helical i have only has male, i did however find this guy before i saw your link to the other svbony:

https://www.amazon.c...0?ie=UTF8&psc=1

 

That female to female should work with the one i have.   I find that even with a shortened eyepiece holder i still need another 10-15mm out but not as far as the adapter that came with the vixen.  The focuser should cure that.



#4 johnpd

johnpd

    Viking 1

  • -----
  • Posts: 902
  • Joined: 12 Apr 2008
  • Loc: Green Valley, AZ

Posted 20 September 2020 - 05:37 AM

Unfortunately I need more infocus than is available for one of my cameras so I am out of luck unless there is an extremely short eyepiece holder or an eyepiece that has a long focus. That female to female adapter should work well. I have one of those as well.

 

Good luck,

  JohnD



#5 markm75c

markm75c

    Viking 1

  • *****
  • topic starter
  • Posts: 893
  • Joined: 17 Sep 2009
  • Loc: Pittsburgh, PA

Posted 23 September 2020 - 07:25 PM

Unforunately the female M42 adapter didnt work, it needed to be M31 to M42 both female.

 

So i found this svbony, it had the right adapter.

https://www.amazon.c...0?ie=UTF8&psc=1

 

It does work directly on the vixen.  However, i cant win, its about 5mm too long to reach focus (well matching the focus of the camera).

So at this point i've decided to forgo the idea of a helical on the vixen.  Ill simply save a focus point that is close on my rigel nstep software (close for eyepiece) then if someone cant quite see it, ill have them push the buttons for focus that are on the scope itself (rigel).  Then when done with optical ill hit my preset for the camera and resume.

 

The helical could be kept on in a similar manner then turned for focus, if i set the focus preset differently as well, but if someone is pressing or turning for focus, i guess why not just use the rigel box on the scope in the first place.

What got me here was the desire to keep it near exactly the same focus on either, but off by even 2000 doesnt take long to get back.  Too much thinking, keeping it simple.

 

Actually using the shorter astromania pin eyepiece holder i have + eyepiece, its already pretty close.


Edited by markm75c, 23 September 2020 - 07:26 PM.


#6 johnpd

johnpd

    Viking 1

  • -----
  • Posts: 902
  • Joined: 12 Apr 2008
  • Loc: Green Valley, AZ

Posted 24 September 2020 - 01:58 AM

I should have thought of this before but I could rack in the scope focus for the eyepiece in the top port and then rack out the SVBONY focus in the camera port and see if I can get them parfocal.

 

JohnD




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