Vixen HR Eyepiece Test on a fast refractor


jimcoble2000
 

The Televue Genesis SDF is one of those telescopes that are really rare ducks in astronomy, being a wide field short focal length refractor (540mm) F/5.6 . Televue is the only maker who I know who currently or ever made this type of refractor which excels at deep sky observing (very rare for a refractor).

Not exactly your ideal planetary scope as it has to use very high power eyepieces to get enough magnification to really do serious work on planets. Until now.

I just got back from Kent's where we observed a couple of hours in variable seeing targeting double stars and carbon stars with my 5 inch F/8 975mm refractor. In the 5 inch scope, 2.5mm eypieces are only good for double stars usually as the power is quite high for the aperture (406x). The 2mm gives 487x, almost 100x per inch of aperture. You need some very steady seeing to use those powers.

I hurried home as Mars was rising with the idea of testing the 2.4mm Vixen HR eyepiece on the planet using my Televue 4 inch refractor with half the focal length of the 5. Vixen created the HR series of 1.25 eyepieces especially for the newest fast dobsonians (F/3) and fast refractors (there are only two models made). This is odd as the market for this type of eyepiece is quite limited. Build quality is superb and quite advanced. Eye relief is a very easy 42 degree field which is quite wide for this type of ocular. For very tight eyepieces they are quite easy to observe through unlike the old soda straw relief of the ortho's and monocentrics.. Everything about these eyepieces is optimized for this kind of power.  Coatings, eye cups, reverse tapered barrels, and removable field stops are all proprietary on the Vixen HR. Superb baffling and blackening of the barrel is also evident. 

In the Televue the 2.5mm eyepiece generates 216x. Performance on Mars was superb. The scope was not overpowered and did not run out of light using this high powered eyepiece. Detail on Mars was excellent.  Using the eyepiece with the longer focal length 5 inch, the 2.5mm would be just too much for all but the steadiest night. In the fast 4 inch, it was ideal. Easily held the planet in the field of 42 degrees while using an alt az platform. Superb color and sharpness.

I think Vixen really did design a superb planetary eyepiece for fast optical ratio telescopes. Everything about them is right. They stepped up in a big way for a very small market. Frankly the HR is the best eyepiece of this type I have seen in 30 years.

Oh BTW we looked at Saturn the other night in my 5 inch using the Vixen HR 3.4mm . Simply breathtaking. Just like you were the Cassini probe. Huge, detailed 3D disc that low power views just can't give you.


Kent Blackwell
 

Mark and I had a good night observing. Mars was behind a huge tree in my front yard so out of the question last night. Glad you managed to view it from your balcony, Mark.

I agree with you say about the Vixens. I was excited by the 2.0mm HR I bought back last month. So much so I ordered the 2.4mm and 3.4mm and never regretted it. Except for the 3.4mm they're not the greatest on planets, at least not with my 5" f/8 refractor due to excessive magnification. But double stars? They're the best, and I manage to keep objects in the field of view even with my DiscMounts alt/az mount, despite powers of up to 475x.

The Vixens have even replaced my all-time favorite high power eyepieces, the Gailand Orthoscopics I bought nearly 50 years ago. Gailands are rarely found on the used market, which I suspect will be the case of the Vixen HR series years to come.

I'll send my observing report later today.

--- jimcoble2000@... wrote:

From: Mark Ost <jimcoble2000@...>
To: kentblackwell <kent@...>, Roy Diffrient <mail@...>, BBAA Groups Io <backbayastro@groups.io>, "vpas@groups.io" <vpas@groups.io>
Subject: Vixen HR Eyepiece Test on a fast refractor
Date: Mon, 31 Aug 2020 04:40:22 +0000 (UTC)

The Televue Genesis SDF is one of those telescopes that are really rare ducks in astronomy, being a wide field short focal length refractor (540mm) F/5.6 . Televue is the only maker who I know who currently or ever made this type of refractor which excels at deep sky observing (very rare for a refractor).

Not exactly your ideal planetary scope as it has to use very high power eyepieces to get enough magnification to really do serious work on planets. Until now.

I just got back from Kent's where we observed a couple of hours in variable seeing targeting double stars and carbon stars with my 5 inch F/8 975mm refractor. In the 5 inch scope, 2.5mm eypieces are only good for double stars usually as the power is quite high for the aperture (406x). The 2mm gives 487x, almost 100x per inch of aperture. You need some very steady seeing to use those powers.

I hurried home as Mars was rising with the idea of testing the 2.4mm Vixen HR eyepiece on the planet using my Televue 4 inch refractor with half the focal length of the 5. Vixen created the HR series of 1.25 eyepieces especially for the newest fast dobsonians (F/3) and fast refractors (there are only two models made). This is odd as the market for this type of eyepiece is quite limited. Build quality is superb and quite advanced. Eye relief is a very easy 42 degree field which is quite wide for this type of ocular. For very tight eyepieces they are quite easy to observe through unlike the old soda straw relief of the ortho's and monocentrics.. Everything about these eyepieces is optimized for this kind of power.  Coatings, eye cups, reverse tapered barrels, and removable field stops are all proprietary on the Vixen HR. Superb baffling and blackening of the barrel is also evident. 

In the Televue the 2.5mm eyepiece generates 216x. Performance on Mars was superb. The scope was not overpowered and did not run out of light using this high powered eyepiece. Detail on Mars was excellent.  Using the eyepiece with the longer focal length 5 inch, the 2.5mm would be just too much for all but the steadiest night. In the fast 4 inch, it was ideal. Easily held the planet in the field of 42 degrees while using an alt az platform. Superb color and sharpness.

I think Vixen really did design a superb planetary eyepiece for fast optical ratio telescopes. Everything about them is right. They stepped up in a big way for a very small market. Frankly the HR is the best eyepiece of this type I have seen in 30 years.

Oh BTW we looked at Saturn the other night in my 5 inch using the Vixen HR 3.4mm . Simply breathtaking. Just like you were the Cassini probe. Huge, detailed 3D disc that low power views just can't give you.