Lunt LS50 and Siebert Black Night binoviewer

Use this section to discuss "standard" Baader/Coronado/ Lunt SolarView/ Daystar, etc… filters, cameras and scopes. No mods, just questions/ answers and reviews.
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saguaro
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Lunt LS50 and Siebert Black Night binoviewer

Post by saguaro » Thu May 14, 2015 2:53 pm

I recently received my Seibert Black Night binoviewers from Siebert Optics (http://www.siebertoptics.com/). I also purchased the Siebert 1.2x OCA that allows my Lunt 50 to achieve focus without over-magnifying the image. I have found that eyepiece pairs in the 15mm - 20mm range work best but higher magnification (around 12mm) is also usable.

Here are my Seibert Black Night binoviewers mounted on my double-stacked Lunt LS50. One of the great features of the Black Nights is their light weight, which is a good match for a small scope like the Lunt 50. I can achieve good balance on my small equatorial tracking mount by sliding the scope forward in the dovetail mount. The double-stack module which screws onto the front of the scope also helps to balance the added weight of the Black Night binoviewers.
Binoviewer and Lunt LS50.JPG
Binoviewer and Lunt LS50.JPG (91.1 KiB) Viewed 1340 times
Black Night binoviewer.JPG
Black Night binoviewer.JPG (114.36 KiB) Viewed 1340 times
After a bit of troubleshooting with Harry Siebert, I discovered the best placement of the two lens elements that comprise the Siebert 1.2x OCA so that I can achieve focus with various eyepiece pairs.

The 1.2x OCA has two lenses numbered #3 and #4. The #3 lens cell is threaded into the binoviewer's 1.25-inch nosepiece. The #4 lens cell is threaded into the rear of the Lunt diagonal's nosepiece (after removing the O-ring on the #4 lens cell), shown here:
Part 4 position for most eyepieces.JPG
Part 4 position for most eyepieces.JPG (91.78 KiB) Viewed 1340 times
I have been able to achieve focus with 15mm and 20mm eyepiece pairs. I also tested this configuration with the one Lunt zoom eyepiece that I have, and the Lunt zoom can achieve focus across its entire zoom range. I discovered later that I can thread #4 a little deeper into the rear of the diagonal nosepiece. This should allow me to achieve focus with my pair of Baader Mark III zoom eyepieces, which have a slightly longer optical path length than the Lunt zoom eyepiece. I will have to wait for clear skies to confirm this.

The Black Night binoviewer is very easy to use, and the self-centering diopters are very well executed. Even the Baader zooms with their undercuts on the barrels stay fixed in the eyepiece holders and don't wiggle around.

It is fantastic to be able to use both eyes for solar viewing. The double-stack module on my Lunt 50 does not significantly reduce the overall brightness of the solar disk, so that's not a concern for me. I do use a Dark Skies Apparel Observing Hood (the white one with 2-layers of black lining) which I find is indispensable for solar viewing.
Lunt 50mm H-Alpha telescope with B600 blocking filter and LS50c (compact double-stack module) on Takahashi Sky Patrol equatorial mount
Skyris 132m camera
Celestron 14 Edge SCT on CGEM DX mount
Vintage Celestron 8-inch SCT

My photo gallery: http://www.astrobin.com/users/robinandcurtis/

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swisswalter
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Re: Lunt LS50 and Siebert Black Night binoviewer

Post by swisswalter » Thu May 14, 2015 6:29 pm

Hi Robin

that setup looks great
Only stardust in the wind, some fine and some less fine scopes, filters and adapters as well. Switzerland 47 N, 9 E, in the heart of EUROPE :)

from 7 am - 7 pm http://www.nanosys.ch

from 7.01 pm - 6.59 am http://www.wastronomiko.com some times vice versa ;)

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Re: Lunt LS50 and Siebert Black Night binoviewer

Post by Derek Klepp » Thu May 14, 2015 7:02 pm

Thanks for the review

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marktownley
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Re: Lunt LS50 and Siebert Black Night binoviewer

Post by marktownley » Fri May 15, 2015 7:39 pm

cool fish!
Image
http://brierleyhillsolar.blogspot.co.uk/
Solar images, a collection of all the most up to date live solar data on the web, imaging & processing tutorials - please take a look!

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saguaro
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Re: Lunt LS50 and Siebert Black Night binoviewer

Post by saguaro » Fri May 15, 2015 10:31 pm

I can now confirm that by threading optical cell #4 a little deeper into the nosepiece, I can achieve focus with all my eyepieces. I purchased a second nosepiece from Lunt for $20. This lets me use the "empty" nosepiece when mono-viewing, and then just replace it with the nosepiece containing the optical cell #4 when I want to use the binoviewer.

Thanks Mark, Derek, and SwissWalter!
Lunt 50mm H-Alpha telescope with B600 blocking filter and LS50c (compact double-stack module) on Takahashi Sky Patrol equatorial mount
Skyris 132m camera
Celestron 14 Edge SCT on CGEM DX mount
Vintage Celestron 8-inch SCT

My photo gallery: http://www.astrobin.com/users/robinandcurtis/

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