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Posts Made By: Chuck Burton

March 14, 2009 05:20 PM Forum: Astro Binoculars

Filters for Deep-Sky Binocular Observing

Posted By Chuck Burton

I have a pair of 125mm binoculars that have been modified to take interchangeable eyepieces. I'd like to get recommendations on what types of filters folks are using for deep-sky work with 100mm+ binocs. I figure my O-III filter would block too much light. Thanks - Chuck

January 15, 2011 06:02 PM Forum: Eyepieces

Field Flattener for Visual Use?

Posted By Chuck Burton

Hi - I'm looking for a "visual use" field flatter for a fast f/6 refractor. I'd get a Paracorr, but they're only for use in a Newtonian reflector. All the field flatteners I see out there for refractors are for photographic imaging. Does anyone here know of, or have any experience with such a device? Thanks!

January 31, 2011 07:16 PM Forum: Astro Binoculars

Barska AB10520 - 100mm Binoculars

Posted By Chuck Burton

Does anyone have any experience with these? I see them advertised for $899 - $1499. They appear to have the same body design as APM's 100mm, 45-degree prism, interchangeable eyepiece version. How do they perform optically? Does the Barska take standard 1.25" eyepieces or just "proprietary" eyepieces? Any information would be appreciated!

May 28, 2015 10:26 PM Forum: Eyepieces

Widest AFOV in a 1.25" 35mm or 40mm EP

Posted By Chuck Burton

Hello! Is anyone familiar with a wide-angle 35mm or 40mm eyepiece in a 1.25" barrel? Looking for a low power sweep with Vixen BT-125 binoculars, with an apparent field of view in the 50-to-60 degree range. If such an animal exists, I'd be interested in your recommendations and impressions. Thanks!

June 1, 2015 07:08 PM Forum: Astro Binoculars

Vixen BT-125-A Binocs: What Eyepieces Do You Use?

Posted By Chuck Burton

Hello! Not much traffic on these beasts in the Bino Forums. I have the f/6.08 version of these binoculars with the 1.25" interchangeable eyepiece feature. I have discovered that many of my 1.25" eyepieces will not come to focus in the BT125's. (Fortunately, 16mm Naglers do! Wow!) Looking for a pair of eyepieces for the lowest power + widest possible field of view. And I'm talking about "apparent" field of view, not true field. For example, I'd love to use a pair of 40mm eyepieces with a 60-degree AFOV, but alas, nobody makes them. So, does anyone out there have a report on what low power/wide field eyepieces they use and that will come to focus in these big binocs? If so, I'd love to hear about them! Thanks!

January 31, 2006 04:55 AM Forum: Eyepieces

Meade SWA 20mm

Posted By Chuck Burton

Chris Brown said:

I just bought(used) one of these, I have never seen one before!!
What is it worth?
I have never seen one at this focal length...Meade's ads don't mention it old?

I have the Meade 20mm and 15.5mm Research Grade Erfle eyepieces I purchased new around 1980. That's probably what you have. These EPs were pretty hot stuff back then. They're great with scopes over f/7. Fast Newts show a lot of coma with these EPs. But contrast is excellent. Great "3D-like" views of nebulae and star clusters. Despite the poor edge performance, the generous AFOV provided some compensation. Mine saw extensive duty in my 16" f/4.5.

What's it worth??!! Take a look on these forums! Everyone's looking for the "holy grail" of eyepieces - myself included. If you find an EP that you like, well then I'd say it's "priceless!" [good luck in your quest!]

- Chuck

like it, the

March 23, 2006 01:17 AM Forum: Equipment Talk

C11 with goto mount/ C11 OTA

Posted By Chuck Burton

Daniel -

That is interesting. A subtle statement from Celestron about the quality of the mount, perhaps?

- Chuck

May 11, 2006 01:58 AM Forum: Eyepieces

Knight Owl Eyepieces

Posted By Chuck Burton


You're right - there's not a lot of info out there on these eyepieces. Here's my experience:

I bought a pair of the 17mm SWAs for use in my binoviewer. I'm using a C-14 at f/11, so keep that in mind. If you've got a fast Newt, YMMV. The 17mm KOs were absolutely awesome! There is a little bit of sharpness fall off in the outer 10% of the field, but it's not nearly as bad as say a 30mm 1rpd. I have an older Meade 18mm SWA that I used to compare a "mono" view with. The 17mm Knight Owl SWA compares very favorably to the Meade 18mm SWA. There might be a wee bit of better contrast in the Meade, but otherwise I could not discern a great deal of difference. Limiting magnitudes were equal. Sharpness across the field was equal. Omega Centauri in the binoviewer with the 17mm SWAs blew my mind. M27 was just as impressive.

I've been in the hobby for 40 years and have looked through a lot of EPs and scopes. I have 4 Naglers - a 12mm T4, a 16mm T2, a 20mm T5, and a 31mm T5. Is the 17mm KO as good as a Nagler? No way. But I will say that looking though a binoviewer equipped with a pair of the 17mm KOs, is just about as awe-inspiring as the one-eyed view through the 20mm Nagler. It's the effect of the binoviewer no doubt, but I can say that these KOs work well with a C-14.

I'm sure this note will draw the ire of a few fellow Nagler owners. For the price, these KOs are certainly worth a try, especially if you have a longer FL scope. Good luck! - Chuck

May 14, 2006 02:45 AM Forum: Eyepieces

big aperture newb, eyepiece list help?

Posted By Chuck Burton

Doug: Having had a 16" f/4.5 for almost 20 years, and being a deep-sky enthusiast also, I feel qualified to make a couple of recommendations for you. With the huge increase in aperture, you'll find that a number of deep-sky objects will bear much higher magnification than you got with your 6". An old "Type 1" Nagler 9mm gave breathtaking views of objects like the Ring Nebula, tight globular clusters and the like. You'll want something that powerful, with the widest possible AFOV. Alternatively, consider a Nagler 12mm T4. For wide field stuff like the Veil Nebula, M42, etc., I used a 32mm Erfle with a Lumicon O-III filter. Unforgettable views, even if the Erfle was a bit soft at the edges. If I had it to do today, I'd recommend a 31mm Nagler if you can afford it. For medium power views of objects like the Trifid Nebula, the Crab, etc., I had a 20mm Meade Research Grade Erfle, one of the finest EPs I've ever owned. Highly recommended with your fast 16". For maximum aesthetics on deep-sky objects, I recommend wide AFOV eyepieces - 65 degrees or more. Due to portability issues, I sold the 16" Newt and bought a C-14. It can't match the widefield views of the fast 16" Newt, tho. You're in for a real treat! Enjoy! - Chuck

January 9, 2007 07:39 AM Forum: Mounts

Bill Schaefer Mount & OLD Skysensor Computer

Posted By Chuck Burton

Hi - Congratulations on owning a Schaefer mount! I own a couple of his mounts myself. Which model mount do you have? I knew Bill Schaefer personally back in the 70's and 80's when he was building mounts. Bill used independent guys to build electronic drive correctors. I'm not sure if he ever had the same manufaturer twice! Do you have a 6-pin or a 4-pin connector? I'm not sure if I can help you, but I'll try. - Chuck