Jump to content

NLC-Banner.thumb.jpg.acb5ba835b9e8bf0718b90539633017d.jpg

Celestron PowerSeeker 127EQ


Alan64
 Share

Recommended Posts

Albeit an open-tube, any Newtonian can benefit nonetheless from the aforementioned enhancement.  Such helps to keep the tube cleaner, and may even help to keep ground-based stray-light from illuminating the back of the tube, in deflecting it away.

Perhaps ideally, holes should have been drilled out of the cell at those three points, and iron or steel plugs inserted and secured...

neodymium5c.jpg.c8737b626786866900dfda90ef2858a8.jpg

The plugs could be twice or even thrice the thickness of that portion of the cell, so to increase the mass, and thereby the attraction between the magnets and the cell.  However, these magnets are a bit brittle, therefore the force of an attraction can crack or chip the magnets, and when attaching the frame.  That's why I had stated, "Perhaps ideally..."  But then, the surfaces of the iron or steel plugs could be overlaid with some sort of cushioning to protect the magnets: wood veneer, thin plastic, et al, and epoxied onto the surfaces of the plugs...

neodymium5f.jpg.8559b8cbfa7bf8b47961f0390d8d1fc7.jpg

...whilst maintaining as flush an installation as possible, and with the surrounding areas.  Therefore the iron or steel plugs should be slightly recessed into the cell, and for a snug fit of the frame against same.

Had I to do it all over again, I might've pursued that, and further, but then this telescope is not that large.

Of course, the frame can also be attached to the cell simply by drilling much smaller holes, and bolting it on. 

However, the use of magnets is a much more elegant and interesting solution.

Link to comment
Share on other sites

In wanting to collimate the telescope more precisely, I did so with the corrector-doublet in place, erroneously thinking that it was not necessary to remove it when using passive tools; specifically, and more easily, with a collimation cap...

1979314390_collimation-081719b.jpg.f8f2f9950fe2d5ec948f4b3054b4411d.jpg

Afterwards, I took the telescope out.  The Moon appeared...okay...at 50x...

081819b.jpg.dfd4c2e606a86beb39900340202796c1.jpg

...but Polaris, at 167x, flared off and outward to its left. 

Back to the drawing-board...

Link to comment
Share on other sites

It is now known that in order to collimate a "Bird Jones" catadioptric-reflector, the corrector/doublet must be removed from the focusser's drawtube, and regardless of whether a laser-collimator or a passive-tool is used.  I overwhelmingly prefer the passive-tools. 

Through the sight-tube(or a modern Cheshire with cross-hairs), when the cross-hairs of the tool, the mirror-image of same, and the primary-mirror's centre-spot, all coincide...

1198963651_sighttube-081819b.jpg.3c61f104710b6987811b1629e7ed9b7f.jpg

...you're golden.  I then inserted the collimation-cap, still without the doublet in place...

498684633_collimationcap-081819.jpg.266dd17e57bfb557f20e1f29de3df5f8.jpg

It was then that I was able to fine-tune the collimation further, as shown, and with the black-dot centred within the primary-mirror's centre-spot; just a slight tweaking.  At that point, the doublet and its cell were reinstalled. 

Link to comment
Share on other sites

Again, note the secondary off-setting...

1552792775_f4off-setting.jpg.caa53a4e6c51765e6d38c786741d1237.jpg

Therefore, again, this is an f/3.3 to f/4 Newtonian, yet with a barlowing corrector/doublet, and for an effective focal-length of 1000mm.  Despite the latter, the views at the lower powers are comatic, as is, albeit somewhat, evident at the edge of this eyepiece's field-of-view...

974369942_071119-30mm.jpg.339ae6b15f4e62131edfd9489ebc9eff.jpg

I have viewed clusters of stars at the lower powers with this telescope, and with the stars at the edge of the view as lines, streaks, and "teardrops".  1.25" coma-correctors are practically non-existent, which would nonetheless be required for this telescope at the lower powers; not to mention the extra expense, and for an entry-level kit.   But then, the views on-axis are fine at same. 

Still, the user would therefore be most comfortable and happiest in using this telescope for which it was designed and intended: for the medium, high, and highest powers.

In that, it excels.  

Edited by Alan64
Link to comment
Share on other sites

The sixth light, on August 19th...

That was the ticket, to collimate it as I had before, and without the barlow/corrector in place.  I knew that it wasn't possible with a laser-collimator, but now I know that it's not even possible with passive tools: my sight-tube and collimation-cap.  

Indeed, the residual overcast left behind by the short storm earlier in the day had vanished.

The Moon through the Tani 20mm Erfle, and at 50x ...

884291247_081919-20mmErfle.thumb.jpg.037bb22a485f604d24c822aa89ab1c25.jpg

I tried to get a good shot through the Vixen 6mm NPL Plossl, and at 167x, but it didn't turn out to my liking.

I used the shaky ES "Twilight Nano" mount for the event, as I was too lazy to haul out the Voyager I alt-azimuth.

The grand prize was realised when I viewed Polaris with the Vixen 6mm, and at 167x.  If the lone spider-stalk contributed anything detrimental to what I saw, it was of little to no consequence.  The seeing was off and on, and as the spherical-primary was acclimating to boot.  I eventually saw glory, with the seeing going in and out still.  The Airy disc presented itself regularly, and had a rather tight first-diffraction ring round it, with successive rings shimmering, dynamic, as they emanated from their host.  Polaris Ab was positioned a little below and slightly to the right of Polaris A, the main star.  Also, Ab did not disappear when staring directly at it.  I observed the wonder for about fifteen minutes, as I had used lemon-eucalyptus spray instead of the deet-based.  I could've stared at the star until dawn, as it was that beautiful; and also, because it doesn't move.

I tried my best to get an out-of-focus shot of the star, but to no avail.  On the extra-focal side, I could see practically all of the rings, and with the outermost rings only slighter brighter than the rest; intra-focally, it wasn't quite as clear, yet it appeared identical nonetheless.  

After everything was taken indoors, I processed the images of the Moon.  Then, as I had been compelled and inspired to do by the sight, I made a virtual "sketch" of Polaris A and Ab, as I saw them, and with my PC paint program...

1421812497_Polaris-081919.jpg.a3fbb01c0957983b694bb446819b4ace.jpg

259664727_Polaris-081919c.jpg.6023214a06f3348e13787256303fa006.jpg

Dare I state that I now possess what is perhaps the finest Synta 127mm f/8 "Bird Jones" on the planet?

Edited by Alan64
  • Like 1
Link to comment
Share on other sites

I've had this 8" pier-extension attached to my larger, GSO alt-azimuth for I don't know how long...

080519.jpg.294ab37ccc7790d7aaee5c2d1faf8a2a.jpg

I thought it was about time to remove it, for a while at least...

820720464_pierextension.jpg.8babd0ab15a51a387a888cb9bd0e558a.jpg

082019.jpg.fc412c6e7562e658ffa6ebf74129ca3a.jpg

There, that's better.  

The eighth light, on August 20th...

At around 9:30 PM, I took the Bird out to face the music of the southern part of the sky.  The primary objective was to observe Ascella, there at the bottom of the "handle" of the "Teapot" in Sagittarius.  When I first ran across it, the star was out of focus, and as you would see when star-testing.  What a lovely blue colour it was, and well-saturated, almost electric.  With the Vixen 6mm NPL, at 167x, the Airy disc of the star was distinct, but only off and on as the star wasn't that far above the horizon.  There would be no splitting of that tight triple with a 5" aperture, despite its lying only 88 light-years distant.  The Voyager I mount, with its slow-motion controls and axis-locks, allowed me to combine the bundled 4mm Ramsden with my Antares 2x-barlow, and for 100x per inch of aperture: 500x, and to observe the  star with minimal shaking compared to that of the smaller alt-azimuth.  The star took 20 seconds to traverse the 4mm's field-of-view, which is quite a considerable TFOV for this particular eyepiece.  My Tani 4mm orthoscopic can't hold a candle to that one in that regard.

Yes, it was a fuzzy blob, of course, but not as fuzzy as that would seem to imply.  I led the star across the field several times, over and over, and did note a brighter core, at which point I patted myself upon the back.

Saturn was gorgeous, slightly swimming in the atmospheric chicken-broth at high power, but not that bad.  I then brought out that Meade zoom that I've barely used, and continued to observe Saturn for a spell.  This zoom isn't half-bad, not at all.  As a matter of fact, as I was enjoying the practically tack-sharp view of the planet at the 8mm setting(125x), I could sense my dedicated oculars trembling yonder.

Link to comment
Share on other sites

The ninth and most-recent light, on August 23rd...

I took the Bird out as soon as it became dark.  First, I observed Jupiter for a spell...

557090827_082319-Jupiter.jpg.d3436d4f39304671c302a7f6bb49308f.jpg

Actually, all four moons were visible.  That afocal shot is by no means indicative of what I saw.  For the very first time ever, with any telescope, I saw the Great Red Spot.  It was tiny, but there it was.  I even saw it rather clearly with the bundled 4mm(!).  I don't know what to think of this 4mm, save that I apparently got one where the lenses were well ground and polished.  How is that possible given the usual reputation of these kit eyepieces?  I guess I'll have to chalk it up to being 2019.

I then observed Saturn for a while...

879645500_082319-Saturn.jpg.4ccbd8035c7bc61f80dfb44811a34420.jpg

Again, that afocal shot is by no means representative of the tack-sharp view I saw.  Through the 4mm, the image only slightly softened, but not by much at all.  

I then aimed the Bird at Ascella, and this time I snapped a shot...

1471446275_082319-Ascella.jpg.ca02cd23ed99ce0e57c8f01418b798ea.jpg

That afocal-shot falls short a bit, however it does reveal the beautiful blue colour of the star; and no, I did not increase the saturation with my PC paint program.

I then disengaged the axes, popped in the GSO "Super View" 20mm, and scanned in the area right round the top of the "Teapot".  It wasn't long before I spotted M28(I think, but I'm pretty sure); a lovely globular cluster.  I did have to use averted vision to see the "diamonds" within, but not that far away from the cluster; almost adjacent thereby.

Despite my success with this particular sample, I still refuse to suggest or recommend a "Bird Jones" to those first starting out.  FLO doesn't even carry this kit.  Still, beginners are attracted to this kit for its low price and short, compact tube, although it does seem to be priced considerably higher in the UK.  Perhaps that will help to keep it out of consideration as a first telescope among most beginners.

For the rest of us, who love to putter and tinker, if you're looking for what is essentially a Chinese finger-puzzle in the world of telescopes, and quite a respectable performer after the unravelling, then you've found it.

Thanks for looking.

  • Like 2
  • Thanks 1
Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share

×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. By using this site, you agree to our Terms of Use.