On Sun, 28 Sep 2003 19:44:03 -0400, Anthony PDC ...reflected:

On Sun, 28 Sep 2003 16:50:08 -0500, Alan W. Craft
wrote:

On Sun, 28 Sep 2003 16:27:14 -0400, Anthony PDC lound_at_charter.net ...reflected:

Hallo all. When I first started observing as a kid I used a cheap
refractor with an equally cheap prism star diagonal.

If they had been made in Japan, then they might not have been
too bad. I have a Sears 60mm refractor, circa 1973, and it's all
made in Japan. It's very good, for a proverbial department-store
refractor...very little plastic, if any, and the optics gave me my
very first view of Saturn, albeit in a weird, fluorescent green.
Of course, I understand that to be merely a characteristic
dictated by aperture rather than by the quality of the optics.

I very much doubt that *aperture* was the culprit - more likely
optical quality, but having said that..."fluorescent green"?

If you have some older Orion catalogs, particularly around
1992 or thereabouts, you'll see a small inset of Saturn, and
precisely as described, and within the ad for their 60mm alt-az
refractor, which were made in Japan at that time. They really
were of very good quality, both optically and mechanically,
although the eyepieces did leave much to be desired, as they
still do. The Orion was virtually a carbon copy of the Sears,
therefore I've little doubt that both were produced in the same
factory, albeit twenty years or so apart.

When I first saw the inset I thought, "Oh, wow, I've seen that
before."

Saturn appears that way in a small achromat at a low-to-mid-
range magnification, for since the only decent eyepiece within
our setup was a yellow-painted 20mm Kellner, with the other
being an "HM 6mm", then it must've been the one with which
my father primarily observed, and the magnification at which I
in turn must've observed the planet when having noted the
strange coloration, that is, 35x.

I still have the owner's manual, and most every accesory,
including a solar projection screen, rather than an eyepiece
filter.

Saturn
never appeared green to me, nor did any other object. Chromatic
abberation was tolerable in my scope, but the offending colours were
the typical red and blue, the edge.

My "mail order" scope was indeed Japanese - f16 job; came with a
crappy alt-az mount in black crackle paint (grin) and a lovely wooden
case with three kellner eyepieces and thick glass, dark green "Sun
Filter" which screwed into the filter threads of the ep's (eek!) -

That smacks of Vixen's solar observation "technique," which also
employs a hole in a prism diagonal housing in order to exhaust most
of the heat and light away from the observer's eye...

I don't believe that your setup would've included that extra diagonal?

Do you recall the brand of that telescope?

I shudder to think what damage I did to my eye(s)!

So do I! Have you noticed any damage?

My father's side of the family is most prone to cataracts. So far,
and at 39, I've been spared.

I think that some of my paternal ancestors must've been Druids...

However, I loved that
scope and whilst I recognised its limitations (a 3" refractor or a 6"
reflector was considered to be the barest minimum then). At any rate,
my little 2 1/2" scope certainly taught me a lot and gave rise to my
love of astronomy.



I would love to have the optics restored, for there's scratches
and perhaps even the wearing away of the magnesium
fluoride coatings. If only I could get the scratches ever
so gently polished out, and then recoated...

Prolly not worth the money Alan.

That's what I've been told...

A gust of wind blew our conservatory
door open, crashed into my scope and smashed the flint/crown glass
achromat objective to bits. The suppliers sent me a replacement lens
in a new cell for free! (they must have felt sorry for me because I
was a teen tyro, suddenly deprived of his hobby). I am pretty sure you
could buy a new objective for MUCH less money than doing a restoration
job.

I'm sorry yours is no more, but I wouldn't dream of discarding the
objective of my youth.

SNIPPED some of my earlier post

If it turns out that I am indeed on the verge of senility :-) are any
correct image star diagonals available of sufficiently good quality
for astronomy?


http://www.telescope.com/shopping/pr...=yes #tabLink

Orion has enough of a reputation to warrant a gamble, notwithstanding
their 30-day money back guarantee, but it's the only one of their diagonals
where the housing is of plastic rather than anodised aluminum(would you
believe that Takahashi's 1.25" prism diagonal housing is plastic, too?
I sent it back, even though the prism was first-rate.)

I got Orion's 1.25" variable polariser, and on sale at the time for $20. It's
very well made, but it's now back up to $30.

In the case of Orion's 2" mirror diagonal, however, I'd get a William
Optics instead for only $20 more, as I've read nothing but accolades.
Mine'll arrive sometime this week, and from Kendrick Astro Instruments.
Anacortes carries them, too, but were backordered at the time.

OK - but that yields a mirror-image too.

I know, but the link also advertises Orion's 2" mirror diagonal.

What I really covet is a high
quality correct-image star diagonal for astronomy.

Did you click on the link and take a look at Orion's offering? It may
be the only way to go, unless you might locate someone who could make
you one, but for a price, of course.

about more glass/surfaces affecting quality blah...just was curious if
some breakthrough had occurred in the reasonably recent past. And
talking about surfaces and extra chunks of glass, when one looks at
the pounds of glass in thse awesome Naglers and other ultrawide ep's
one is apt to question this rule of thumb (I own a Meade 14mm
Ultrawide, and astonishingly wonderful it is too - in spite of its
complement of EIGHT lenses!)

I've yet to sample the world of 2" oculars, but its time is coming.

So, I'm wondering - is there some optical rule which gives the OK to
use multiple glass elements in eyepieces for example, but any optical
device which gives a correct image for astronomy is anathema?

Not that I'm aware of, other than having read that said diagonals
are primarily recommended for terrestrial use.

Regards,


Anthony

Alan