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Posts Made By: Dan D DuBal

January 10, 2003 09:48 AM Forum: Deep Sky Observing

What does it take to view the Veil nebula?

Posted By Dan D DuBal

Ah, yes. The Veil is always a favorite of mine.

I've seen the brighter arc in 8x32 roof-prism binoculars and the entire "loop" (with inner "patch") in both my 3-inch refractors (f/6.7 and f/6).

These views were from dark sites with limiting mags. around 6.5. I should try it from my backyard (~5.3 l.m.) and see how the MK67 does.

Thanks for sharing.
Best wishes.
-Dan

January 14, 2003 08:32 PM Forum: TeleVue

Pronto for moon & Planetary?

Posted By Dan D DuBal

Just ballparking, here, but...
First, some assumptions: good Pronto optics, good diagonal & eyepieces, and good seeing.

Moon: Luna's brightness makes pushing beyond ~100X per inch do-able, but that's pretty-much "empty" magnification (no gain in discernibility/resolution beyond lower powers; just a bigger image). I'd expect to spend most of my time in the 100-150X range. Still, "maxing out" on Luna *can* be a kick, even if one doesn't see any more detail.

Mars: Larger features (i.e. Syrtis Major, Erythraeum, Tyrrhenum, Acidalium, perhaps more), polar ice cap(s), and a gibbous phase are all do-able. Surface likely a pink-ish orange. Ice will be *white* -- you won't mistake it for clouds or dust.

Jupiter: Expect some irregularities in widths, hues, & tones of belts &/or zones (i.e. clumps, lumps, or "this section's darker than that one," or "this belt looks browner" -- that sort'a stuff). Large ovals can be seen, given enough contrast (oval vs. background of Jupiter). Same goes for barges/disturbances. Shadows of Jovian moons should be easy & obvious. Given sufficient contrast *and* excellent seeing conditions, the moons themselves may also be seen (though not often) against the background of Jupiter. Great Red Spot and its "hollow" should also be available. Hues will include brownish, cream, grey-blue, and perhaps pinkish.

Saturn: Cassini, no problem. Encke "Minima" should also be do-able. Polar region ("olivine cap") will stand out (darker than rest of globe), as will the Equatorial Zone. Shadow of rings on globe can be seen, as can the shadow of the globe on the rings. Yellow-brown, cream, olive-brown, & white-ish blue.

Recommended "filter": a whole lot'a careful observing and a whole lot'a patience.

Best wishes.
-Dan

January 15, 2003 09:50 PM Forum: Maksutovs

MK67 Focus Question

Posted By Dan D DuBal

Ad copy for Orion's Argonaut Maksutov-Cassegrain was as follows: <>

This copy always confused me. It implied that 1.25-inch eyepieces -- as you've noted/heard -- would not reach focus in a 2-inch diagonal. It also implies that 2-inch eyepieces, as well, would not reach focus, as the 2-inch diagonal/eyepiece combo would not allow enough inward focus.

However, a review of the Argonaut in "Sky & Telescope" (April '99 issue) noted that a 2-inch diagonal was actually *required* for 1.25-inch eyepieces. The S&T article -- *not* the Orion ad copy -- better fits my own experience with the Intes MK67 (Intes branded; not the Argonaut). Orion's recommendation for 1.25-inch eyepieces simply would not work in my MK67.

As per my understanding of the Intes MK67's focal plane position relative to the rear of the scope tube, I included a 50mm extension tube (2-inch diameter) with my MK67 order back in 2000. When coupled with a 1.25-inch diagonal, the extension allows all my 1.25-inch eyepieces to reach focus. *Without* the extension, a 2-inch diagonal is needed.

In other words: all Intes-branded MK67s of the past few years were/are designed with 2-inch diagonals in mind. As for Orion's old ad copy -- I'm just not sure how accurate it was. Perhaps early Argonauts were spec'd a little differently (focal plane further "forward," nearer the focuser) than latter versions.

Nutshell:
-If I were ordering a new Intes MK67 today, and I needed it to reach focus with a 1.25-inch diagonal, I would *expect* it to require an extension tube to do so.
-If I needed the MK67 to reach focus with a 2-inch diagonal, I would *expect* it to do, right out of the box.
-If I had any doubts or worries as to my expectations, I'd check with the dealer.

I hope this helps.
Best wishes.
-Dan

January 31, 2003 11:09 PM Forum: Celestron

Anyone recognise this controller?

Posted By Dan D DuBal

Gotta be from a mid-to-late-80s vintage Powerstar or Powerstar II.

I'm not sure how "universal" the controller may have been, across Celestron's late-80s/early-90s SCT offerings. Does anyone else know if this controller was compatible with, say, the original Ultima 8/PEC?

Best wishes.
-Dan

February 3, 2003 09:49 AM Forum: Binoviewers

Binoviewer collimation

Posted By Dan D DuBal

Hi Marc. It may be *neither* the Burgess nor the viewer.

Two questions came to mind:

-Where does the laser beam strike the objective when the viewer is removed (i.e. checking alignment of the focuser itself)? True, the Burgess may be perfectly square, but I'm wondering about the main tube itself, and/or the focuser's mounting flange. I'm guessing you've already checked alignment of the focuser, but I thought I'd ask, anyway.

-When placed in the *other* eyepiece collar, where does the beam land (relative to the first collar's spot)?

My "gut" tells me a ~15mm offset/tilt may be practically invisible at the 150's eyepiece. (Of course, I could be completely wrong.) However, if the other collar shows a significantly different/"conflicting" offset, merging the binocular images may be troublesome.

If significant astigmatism is being introduced, you should be able to see the aberration in a star test (one eyepiece at a time, in the viewer).

Best wishes and luck.
-Dan

February 8, 2003 09:27 AM Forum: Deep Sky Observing

Phew!

Posted By Dan D DuBal

I must admit, Jeff; your sale ad did surprise me. I may have even sighed at the thought of your letting go of that unique Meade. I'm glad you changed your mind.

I wish you many more wows and grins.
-Dan

February 11, 2003 08:33 AM Forum: Equipment Talk

Meade standard coatings

Posted By Dan D DuBal

Hi Phil.

My understanding of the new UHTC vs. "standard" coatings is this:

Prior to UHTC, *ALL* Meade cats were supplied with EMC (i.e. none had "lesser" coatings).

Now, with UHTC being Meade's best, they also offer a "standard" coatings group. Meade's new "standard" coatings are not the same as their prior EMC. The standard coatings are less reflective/transmissive.

That's my understanding, anyhow.

Best wishes.
-Dan

February 15, 2003 11:41 PM Forum: Deep Sky Observing

Darn floaters in the eye

Posted By Dan D DuBal

You're on the right track, Ivan. Whenever possible, orient your viewing position so that eyepieces are held parallel (or roughly so) to the ground. View along the horizontal (look neither up nor down), and your floaters will likely drift down and out of the way, below the eye's image bundle. Smaller floaters may still get in the way, but they're certainly less annoying than the "monsters." My two primary floaters (one per eye) are quite large and intrusive (especially when viewing Luna, Sol, and the brighter planets), so I consider star diagonals *essential* --not merely convenient.

Luckily for us, floaters don't wreak as much havoc when we're viewing stars, clusters, and nebulae.

Best wishes.
Dan

February 19, 2003 08:35 PM Forum: Eyepieces

Is anyone familiar with Optica B/C Eyepieces

Posted By Dan D DuBal

Ny understanding (no guarantee it's correct) is that they belong to the University Optics/Kasai/Kohki/"Circle-T" family of Abbe orthoscopics (i.e. same manufacturer). As such, I would expect the Opticas to perform as well as the other members of the family.

My 6mm Circle-T is superb. Have you had a chance to try your 4mm?

Best wishes.
-Dan

February 19, 2003 10:15 PM Forum: Deep Sky Observing

Re: Callisto in Transit

Posted By Dan D DuBal

I'll hoist my "cup" to that, Ron. ;^)

Nice to hear, Ed. I haven't caught Callisto in transit, but an Io transit (shadow, too) once kept me staring -- and grinning -- for hours, through my own three-incher (Pentax 75).

I need to get off my butt and do some more staring.

Cheers and best wishes.
-Dan