Posts Made By: Peter Bilotta

I recently purchased a Nikon zoom eyepiece on AM only to discover that the top element of the moving zoom mechanism is quite dirty, interfering with high power viewing. Apparently, the only way to access the inside for cleaning is by loosening several extremely tiny hex screws (probably .5 mm) on the exterior of the barrel. Unfortunately, my local camera repair shop tells me that this requires a proprietary Nikon tool that hardly anyone has.

Does anyone out there have experience with these or know of someone who could disassemble and clean an eyepiece like this?

Thanks for any advice you can provide.

I wasn't certain if this is better here or under the Telescope Making forum, so we'll try it here.

I have a Celestron/Vixen 6" Newt on which the secondary coating has started to corrode. The coatings on the primary mirror still appear to be fine with the exception of some edge corrosion. Am I better off replacing just the secondary at this time, or simply having both recoated for the $75-$100 cost of new coatings?

Thanks for your expert advice.

I love the performance of my old Ultima 2x shorty barlow, but I'm finally fed up with it's incredibly tight tolerances. As you may know from many posts and evals, many eyepieces are an extremely tight fit in this barlow - darn near impossible for my Axioms.

Any suggestions for the best barlow to replace this (preferably a shorty)? I'm particularly interested in the Orion and Antares "APO" models, which appear from many reviews to be identical optically. Any idea if these two Ultima clones have the same tight fit problem?

Thanks for your recommendations.

- Peter

Thank you all for some excellent advice. Quite a lively discussion.

It sounds like barlowing an already excellent planetary like an 7-9mm ortho or RKE may be the best solution for increased eye relief for those of us on a budget with fast scopes (mine's a 6" f/5). They lead to two additional questions . . .

Does anyone have any experience with the 5mm Ultrascopic versions that already have a barlow built in, yielding the eye relief of a 10mm. Does this perform better or worse than using a separate barlow.

And second . . . the best barlows for this application?

Thanks again!

Jared:

I prefer the Ultimas because of their excellent contrast and sharpness - better than other plossls I have tried. I have virtually a full set (7.5mm - 30mm) and use almost all with my glasses on because of my astigmatism. You can get them used on Astromart for $50-$60.

Skip the 42mm - what you gain in view because of lower magnification you lose because of the narrower FOV. The best you can do is the 35mm (a big monster) or the 30mm. By the way, the Ultimas are identical to the Orion Ultrascopics and Antares Ultras (same eyepieces, different brand), and these brands offer slightly different focal lengths if you need them, such as 15mm and 10mm.

The 7.5mm and 12.5mm Ultimas are outstanding planetary eyepieces. Excellent contrast, tack sharp and good color. While they do have tight eye relief and require taking my glasses off to take in the full FOV, I usually keep my glasses on because observing planets only requires having a good view of MOST of the FOV.

I have faced the same challenge with eye relief and have tried many of the options like the Epics and Long Views. Sorry, they just don't compare to a better mid power eyepiece with longer eye relief coupled with a high-quality barlow (many longer view eyepieces just incorporate a barlow). So, I've stuck to my 18mm Ultima, 12.5 Ultima and a 9mm University Optics Ortho barlowed for my high power observing needs. I've found the Celestron 2x Ultima and Antares 3x Ultra best for this AND AFFORDABLE TOO!

Hope this helps.

For what it's worth Tom, here's what I would do . . .

If you are going to be using the higher powers primarily for the planets and moon, buy all three UO orthos - the 12.5, 9 and 6 - and sell your sirius 9 and celestron 6 plossls on Astromart for $35 each. That way, you will have a perfect low to mid power set with your 30mm, 25mm and 12.5mm, and a perfect high power set for the planets with your three UO orthos. I know a lot of folks who would kill to get three UO orthos so cheaply.

I have experimented with a lot of different plossls on planets, and with the exceptions of the Celestron Ultimas and Televue plossls, nothing beats the University optics orthos in the under $100 range. The orthoscopic design is superior for planets because of its excellent optical and color correction. The only drawback is that it has a narrower field of view than a plossl (45 degrees instead of 50).

Best of luck in seenig the GRS!

Surplus Shed also has plastic ontainers for 1.25" eyepieces for just $.75 each. They are not the bolt type, but rather have a slide on top. The price is right for less pricey eyepieces. Go to www.surplusshed.com and check out their eyepiece section.

While I have not tried it, I recently found a comparision review of zooms online at Cloudy Nights Reviews http://www.cloudynights.com/eyepieces/zooms.htm. The Nikon zoom was a clear winner over other quality zooms - much better than the Orions, Vixen and TeleVue. It even gave a much higher priced Leica a run for the money.

Thanks Mike, that is very helpful. I am contemplating replacing my 9mm UO ortho (yielding 166x, 180x, 200x and 250x in my current set) with a 10mm Ultrascopic to create a parfocal set with my Ultimas. This would change my spacing to 150x, 180x, 200x and 225x). I'm trying to figure our if the 225x might be better than the 250x as a realistic increment for planets. What do you think?

Throughout the discussions like these, no one ever seems to mention the venerable 6" reflector, so I will. There is a reason that a 6" Newtonian on either a Dobsian or equatorial mount was the mainstay of amateur astronomy prior to the SCT and a reason it has stormed back on the scene. Because it is an all-purpose, portable instrument that is versatile for just about every type of observing - particularly for the beginner or intermediate.

A high-quality 6" f/8 or f/5 Newtonian is razor sharp and provides both excellent deep sky images that come close to and 8"SCT and outstanding planetary views that rival a 4" refractor (moreso with the f/8). It is very portable, cools down quickly, and best of all, is extremely affordable. A complete set up can be had for $500. You can even sell resell it quickly if you want to upgrade in the future. And, should you happen to lose interest later on (heaven forbid), no great loss.

I own a 4" refractor, 6" f/5 Newtonian with excellent optics and an 8" SCT. The 4" and 8" just collect dust because the 6" Newtonian is convenient, easy to move and use and is the best balance for general observing. It has given me some of the best deep sky and planetary views I have ever had.

That's my 2 cents worth.