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Some Handy Binoviewer Configurations

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#1 Jeff B

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Posted 17 October 2021 - 11:42 AM

I have always really liked the Denk OCS/Power switch system.  Nothing like having three different powers available from a single pair of eyepieces with the slide of a couple of switches.

 

However, I never really liked the fact that, with the Newtonian configuration, the bottom of the OCS element would most often, with my newtonians, intrude into the light path with the low (~1.3X) and mid-power (~2.3X) switch positions.  While I will readily admit that the visibility of the intrusions is typically subtle to me, I just do not like it.   I also find that I use the low power switch setting very little as I mostly use my newts for high power lunar/planetary/double star viewing.  The "issue" is the middle newtonian spacer tube, which provides the necessary (and adjustable) spacing between the OCS element and the switch to allow the system to reach focus with all three switch positions.  Unfortunately It pushes the OCS element into the light path slightly even at the mid-power setting.

 

Then I had the idea.

 

I also have and older OCS element hanging around that's labeled "Multiplier", which has a higher magnification factor (~1.5X higher) than the standard "Multi-Purpose" elements.  Using the "Multiplier" with my refractor viewer configurations has always meant I needed to rack out the focuser quite some distance to reach focus.  So I figured that if I attach the Multiplier directly to the Denk 2" nosepiece, I could ditch the spacer tube when using my newtonians.

 

And it worked.  

 

With this configuration there is no intrusion at all of the Multiplier element into the light path.  Plus, I have no trouble using all three switch positions, never having to slide the viewer outward in the focuser at the highest power setting to reach focus.  The resulting maginfication levels are very approximately 1.8X, 2.7X and 4.0X which is ideal for my newtonians.

 

Since I have several viewers, I also got a set of T2 dovetail and Quick Changer adapters from Precise Parts and standardized on the T2 quick changer system as you see in the pictures.

 

Jeff  

Attached Thumbnails

  • High Power Newtonian Configuration, Denk II.jpg
  • High Power Newtonian Configuration, CZAS.jpg
  • Denk II, T2 Quick Change Dovetail B.jpg

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#2 crixt

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Posted 17 October 2021 - 12:11 PM

Thanks for posting this. I have been in the weeds figuring out ways to get my binos to work in each of my scopes in different configurations. Having both power and filter options available with each on the 140 is particularly nice. Skies have been clear and FL weather is turning…less hot, less bugs. 



#3 Jeff B

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Posted 17 October 2021 - 07:56 PM

You're welcome crixt.

 

Yes, entering the world of bino-viewing can be downright confusing and frustrating with all of the different system configurations possible...and then you lump on top of that the desire to use your viewers with all of your scopes and you get this

 

bigshock.gif gaah.gif question.gif Eyecrazy.gif

 

To name a few.

 

So I started this thread to have a place to highlite configurations that I have found work well for me.  

 

And here is another newtonian configuration, but optimized for low power, at ~1.3X magnification. 

 

It uses a Denk multi-purpose OCS element (in this case the 45mm clear aperture one), the newtonian spacer tube (which allows me to customize the system to the particular newt) and an older Denk 2" top section that has a reducer element in it.  It is topped off with the Baader T2 Quick Changer system.  I use this strictly for low power and it works well at that.  The viewer is a CZ prism unit with 30mm clear aperture inlet and is an ideal low power viewer as is my MKV.

 

My newtonians have lower profile Feather Touch focusers and are set up strictly for visual use so.  Some newts need a spacer to reach focus in mono-vision and the standard Denk power switch system can work extremely well with them.

 

Jeff    

Attached Thumbnails

  • Newtonian low power system.jpg
  • Denk 2 inch Nosepiece with Reducer.jpg


#4 Jeff B

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Posted 19 October 2021 - 02:19 PM

One of my favorite viewer configurations for refractors and SCTs/Maks is identical to the high power Newtonian configuration from above but with the newer "Multipurpose" cells instead of the "Multiplier" cell.  This configuration is mentioned only briefly in the current Denk Binotron manual.  This will give you the lowest powers you can get with the Denk Power Switch system, ~1.2X, 1.8X and 2.3X. 

 

However, with your typical 2" diagonal, to effectively use this configuration for all three switch settings, specifically the lowest power setting, you have to have about 180mm of back focus available with your refractor.  Fortunately, this is no problem with my bino-friendly refractors and my TEC triplets (they all have ~ 180mm of back focus).   

 

This configuration works well for SCT and Maks too, especially at the mid and high power settings as you are close to the back focus that gets you optimal optical performance for these scopes, especially at the high power setting.  

 

If you like this configuration but need a little more back focus, you can try to dig up what I call the 1.4X OCS element.  This is an earlier OCS element that has a slightly higher magnification than the current OCS elements and thus at each switch position, will give you slightly higher magnifications and about 10-15mm of extra back focus.  The trouble is, they are also labeled as "Multipurpose" OCS elements, however, you can readily identify the 1.4X units since the OCS's element retaining ring is almost flush with the top edge of the cell body.   The more current, lower power OCS units (both the 37mm and all of the 45mm units) have thinner elements and the retaining rings are recessed a few mm's below the top edge of the cell body.  You can see that in the attached photo.

 

Jeff

Attached Thumbnails

  • Denk II, OCS in Nosepiece.jpg
  • 1.4X OCS left, 1.3X OCS Right.jpg

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