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Denkmeier II Binoviewer - Help Needed

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#1 JF4Bama


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Posted 07 December 2012 - 07:32 PM

I just bought a used Denk II. I tried it with a pair of Naglers 11mm's and could not focus in on anything. I could see a big round something but I never could get it to focus with my refractor. I feel like it has something to do with the focal length ... but I'm not really sure ... any ideas on how I can get this bino to work?


#2 rockethead26



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Posted 07 December 2012 - 07:51 PM


Do you have the instructions for using the Denks with a refractor? If not you can download the PDF from the Denkmeier site. Make sure you have all the parts.

#3 johnnyha


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Posted 07 December 2012 - 07:54 PM

You probably need more in-focus as is typical of refractors, so you will have to use a barlow to reach focus, or use a smaller diagonal - or both. Usually though a 1.7X-2X barlow will get the binos to reach focus.

You can also try looking straight thru without the diagonal and the binos will probably reach focus.

#4 JF4Bama


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Posted 07 December 2012 - 08:08 PM

I do not have the instructions ... I will look on the website. I will also try the barlow.

#5 MikeBOKC



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Posted 07 December 2012 - 09:30 PM

I am assuming the Denk IIs operate like the Denk Big Easy. If so, how you use them with a refractor depends on whether you are using a 1.25 or a two inch diagonal in your refractor.

If a 1.25, thread the OCS into the filter threads in the diagonal.This puts the OCS in front of the diagonal. That gives you regular power. You can also remove the optical nosepeice from the body of the binoviewer and replace it with the hollow nosepiece if one came with youre unit. Leave the OCS in the diagonal. This will give you 2.5 power, sort of like a Barlow.

If you are using a 2 inch diagonal, there is a round T adaptor that should have come with the unit. You thread the female side of the OCS cell into that and then thread the whole thing into the front of the diagonal with the OCS side inside. That should allow you to reach focus.

If the Denk II does not come with those parts you may want to try the Barlow route.

#6 JF4Bama


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Posted 08 December 2012 - 01:56 AM

Thank you ... I have some equipment I need to find. Looks like my bino came incomplete.

#7 junomike



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Posted 08 December 2012 - 09:01 AM

Jeff, The Denk II's may not have originally included the necessary OCS (Optical Corrector System) as It's not a requirement for use in an SCT (or MCT).
Only Refractors and Newts require the OCS as their Focal Point is fixed and these systems are sold with the OCS.

If your Bino's have the Power X Switch attached you could try using the Barlow lens to try to reach focus.


#8 Eddgie


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Posted 08 December 2012 - 10:37 AM

Do you just a Denk II bino head, or do you have a complete Denk II Super-System?

The Denk II Super-System comes in a case and should include a long rectangular Power Switch that is located at the bottom of the bino housing. It also includes a set of black spacers and a large lens (the OCS) that can be used for refractors to provide the necessary back focus.

If you only have the Denk II, then you will need to either use a barlow lens, or purchase the necessary OCS lens.

The OCS lens screws into the front of most standard 2" diagonals and then the diagonal is inserted into the focuser tube in the normal manner.

A standard bino, especially when used with a 2" diagonal, will not reach focus in many (perhaps most) refractors.

Most Barlos will be problematic as well. Even if you find one that screws into the nose of the Binoviewer, it will usually give more power than stated, and if you put it in front of the diagonal, it will give waaaay more power than stated because of the length of the light path.

For this reason, the OCS a bit better because usually it willl provide about 2.1x magnification and it is not easy to get this low a magnification using standard barlows.

If you want to use a barlow and can find one with threads that will screw into the bino nose, don't use a shorty. Try to find one of the old style barlows that had the very long barrel. This will ensure that when used with the long light path of the bino, the magnification will remain closer to the stated power.

I do not know what threads Denk uses inside the nose of their binos but I think it is the standard filter thread, and many barlow lenses use this thread.

#9 JF4Bama


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Posted 08 December 2012 - 08:17 PM

Thanks for the post. I have some work to do.

#10 faackanders2



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Posted 09 December 2012 - 11:06 PM

Call or e-mail Russ at Denk, and he will set you up with correct OCS. Also have you pulled system in and out to manually focus?

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