Friday, January 20, 2012

A cure for Zenith neck

Note: The following post was originally posted on January 2, 2012 but I added new information today in the comments as a result of communications with Vic Maris at Stellarvue.

I like the finderscope Meade includes on the LX200, but my neck and back disagree. Not only disagree, they finally rebelled a couple weeks ago while I was zeroing in on the Pleiades almost directly above my head.

So I ordered the Stellarvue F50-2 9x50mm Deluxe Finder scope from Oceanside Photo & Telescope (OPT) because it has a diagonal with a rotating back, so you can easily look through the eyepiece, whether your telescope is aimed at objects near the horizon or straight up, simply by loosening the rotator locking screw to adjust the eyepiece to the angle you want. All that stops it from rotating a full 360 degrees is my optical tube.

Support staff at OPT said my current Meade mounting rings will work with the Stellarvue finder. They were right, saving that expense. That doesn't happen often.

Also, the Stellarvue finder comes with a 1.25" 23mm eyepiece with reticle, but no illuminator. You have to buy the illuminator seperately... or not.

I have had a Meade 9mm eyepiece with illuminate reticle for a couple of years, but don't use it much due to its narrow true field of view in my telescope. I was happy to find that its illuminator screwed into the new Stellarvue reticle eyepiece and works perfectly.

So now I have two reticle eyepieces with different powers and fields of view that can share an illuminator. And, because the Stellarvue finder accepts other 1.25" eyepieces, I can use its 23mm reticle eyepiece on my telescope as well.

Here are my "first" impressions based on two nights of observations.

The Stellarvue finder scope appears to be solidly built. It looks good, feels good, and the moving parts work smoothly. The eyepiece has a focuser for the reticle crosshairs. The finder has a helical focusing ring which moves very smoothly.

There is a learning curve involved in using this finder, because it has so many moving parts grouped together in such a small area. My Meade finder scope has only one moving part, the focuser. The Stellarvue has six (once you add an illuminator). But you get the hang of it quickly.

Here's a rundown of those moving parts, starting where the scope ends and the diagonal begins: (1) Locking rotator screw to hold the diagonal at the angle you want for comfortable viewing; (2) rotator (this is done by turning the diagonal); (3) helical focuser; (4) screw to lock the eyepiece in place; (5) focuser for the reticle crosshairs, and (6) on/off brightness knob for the illuminator.

It does take an hour or so to get used to all of these and to find them easily in the dark without looking. That's particularly the case for the helical focuser and the reticle focuser, because they are so close together. But they are spaced almost an inch apart, and the knobs have a very different texture.

This is not a complaint. It is exactly because of all of these moving parts that the Stellarvue finder scope is so versatile. And more moving parts on the Stellarvue means fewer moving parts in my neck and back.


  1. Comment on my post of this article on Cloudy Nights forum: Hi Mike - I have, and like, the same finder and have used it for five years. The only real complain I have is that the finder doesn't hold alignment when the rear cell is rotated to change the orientation of the 90 degree diagonal. Not really a huge problem, but irritating nonetheless.

  2. Comment on my post of this article on Cloudy Nights forum: I also have the F50M2 and love it. What's really cool is putting in a 24Pan with an O-III filter and looking at the Veil or North American Nebula. Also try a H-beta filter and the California Nebula.

  3. Comment on my post of this article on Cloudy Nights forum from Shane: I have the same "problem". Actually, the mis-alignment is so poor when I rotate the back, the object scribes a circle approximately 1.5-2 degrees in diameter, meaning that as a finder, the SV50 is useless. I am forced to use it with the back permanently fixed.

  4. Vic Maris at Stellarvue was very responsive when I asked him about the alignment problem. I'm really impressed with his finder in spite of the alignment issue and also very impressed with his customer service. He gave me the following information about the rotating problem:

    "This is an issue with this design. To keep the price in line and to keep the weight minimal, there is no lens cell and since it is extremely short in focal length and there is some necessary play in each component, this crosshair issue arises."

    "This includes the tolerance of the eyepiece insert tube, the centering of the reticle in the eyepiece, the variation in the threaded helical focuser, the angle and position of the prism relative to the objective."

    "While there is little difference visually as you rotate the back end, with this extremely small amount of variation, it does affect the position of the cross hair in the magnified eyepiece relative to the FOV."

    "I have thus far [not] found any way to solve this issue without doubling the price. That would take an otherwise perfect finderscope and render it too expensive for the market."

    "I appreciate your positive reviews. I personally designed this finder and applied for a patent when I did so. What I did not expect was the multi-component tolerances keeping the crosshair from remaining perfectly centered. I have put some time into it but the solutions are relatively expensive."

  5. I have the same Stellarvue finder and think it is one of the best things I have ever bought for this hobby, no matter how bright and sharp my Tak 50 mm finder is, being comfortable while viewing is better.


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