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Nebular/skyglow filters for Questar Brandons

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#1 Terra Nova

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Posted 01 December 2019 - 04:20 PM

Does anyone here know if anyone makes any narrow band/nebular/skyglow filters that thread into the thread-in Questar Brandon eyepieces?


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#2 rcwolpert

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Posted 01 December 2019 - 04:47 PM

Ooh...good question!  (Waiting for the answer. popcorn.gif )


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#3 Gregory Gross

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Posted 01 December 2019 - 05:14 PM

Look at the Optical Glass Filters section of Questar's Product Listings page. There, you'll find a Broad-band Light-Pollution Reduction Filter (#19288) and a U.H.C. Broadband Light Pollution Reduction Filter (#19290), among other filters. Maybe the "U.H.C. Broadband" is better referred to as a narrowband filter.

 

Company Seven's Questar price list page indicates that #19288 runs $161 while #19290 runs $166, though it appears these prices were last updated quite some time ago (March 2008).


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#4 coopman

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Posted 01 December 2019 - 05:15 PM

Brandon sells filter adapters for their eyepieces that allow the use of other brands of filters besides theirs.  I would think that they would work for the Questar Brandon eyepieces also, unless they are made to be diff. from the normal Brandons.


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#5 nicoledoula

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Posted 01 December 2019 - 05:58 PM

Or simply lay one on top of the eyepiece.


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#6 Optics Patent

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Posted 01 December 2019 - 06:00 PM

Latest price list (2017):

 

19288 Sky Glow Broad-band Light-Pollution Reduction Filter for photo-visual use. Improves contrast of deep sky objects by blocking frequencies of light from city limits. Threads onto bottom of Questar Brandon eyepieces.(470-540nm >640nm) ............... 195.00
19290 Ultra Block U.H.C. Light Pollution Reduction Filter, Ultra high contrast for photo-visual use. Improves contrast of deep sky objects by blocking frequencies of light from city limits (475-520nm) ....................................................................... 220.00
19289 Oxygen III Light Narrow Band Filter, Contrast for photo-visual use. Improves contrast of planetary and emission nebula deep sky objects by blocking frequencies of light from city limits .................................................................................... $240.00


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#7 Terra Nova

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Posted 01 December 2019 - 09:11 PM

Wow! Thanks Ben. This is pricy tho! I’ll have to think about that!



#8 Terra Nova

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Posted 01 December 2019 - 09:12 PM

Or simply lay one on top of the eyepiece.

That’s certainly a good way to get an idea of well one might work and do a sort of cost/benefit analysis.



#9 Terra Nova

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Posted 01 December 2019 - 09:15 PM

Brandon sells filter adapters for their eyepieces that allow the use of other brands of filters besides theirs.  I would think that they would work for the Questar Brandon eyepieces also, unless they are made to be diff. from the normal Brandons.

Since the Questar Brandons screw into the eyepiece mount, I wonder if these would work. I’ll have to take a closer look at the Q-Brandon eyepiece barrel and a regular 1.25” filter.



#10 Gregory Gross

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Posted 02 December 2019 - 12:21 PM

Would the addition of an adapter for non-Brandon-threaded filters extend the length of the eyepiece barrel to the point where the attached filter would hit the bottom of the eyepiece holder and prevent the threads on the eyepiece from reaching the threads on the eyepiece holder?

 

Also, I was not aware that Questar made an O-III filter available -- interesting. But in my experience, O-III filters (and, for that matter, any contrast-enhancing filter) work by removing light at certain bandwidths. As such, they work best on larger-aperture instruments. I wonder if a 3.5" Questar would have enough light grasp to make O-III filters, which typically can be fairly strong, useful for visual work.

 

Terra, if you have a regular UHC or O-III filter in your collection and can lay it on top of an eyepiece in your Questar, let us know the results of your test.


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#11 Altair54

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Posted 05 December 2019 - 10:31 PM

I've tried a nebula filter on a Televue eyepiece on my Questar 3.5.  There is not enough aperture for very much light to come through the filter.  If anyone has different results, I would like to know how it can be done.



#12 Mike Allen

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Posted 13 December 2019 - 07:48 AM

I've tried a nebula filter on a Televue eyepiece on my Questar 3.5.  There is not enough aperture for very much light to come through the filter.  If anyone has different results, I would like to know how it can be done.

This has been my experience also.  I've tried using the Televue O3 and Nebustar filter on my 1999 Q 3.5, and I feel that the image is dimmed too much.  The Vernonscope filter adapter ring for standard eyepiece threads does work with Questar Brandon eyepieces.  Vernonscope also makes an adapter ring to use Questar/Vernonscope filters on standard eyepieces.  It is a fairly inexpensive item if you want to experiment with filters other than Questar.  For my eyes, and observing conditions, a four inch optic is the minimum I need before a deep sky filter becomes beneficial.  This is slightly off topic, but I do used Vernonscope colored filters on my Questar eyepieces.  No problems threading them on, and I find they are helpful when observing the Moon and planets.


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