Ahem.

Buying numbers of inexpensive mounts as well as scopes has given me a certain
level of non-parochial education in these matters.

The Orion SVD polar scope adds the depiction of Cassiopeia (the assumption being
that it is circumpolar to the users of this device) to the target, but you can
do this mentally once you see the target. The webpage I most quickly found is
here -

http://www.galacticfool.com/polar-align-eq-mount/

I have not read the whole thing, but you see the photo of most of a similar
target which even includes the position of Ursa Major. This is clearly
discriminatory to southern hemisphere users.

That said, I just get Polaris close to center in the 20mm EP and always get
successful 3 star alignments in both the LXD 55 and 75, with decent visual GoTos
and tracking. Once I decide to try a camera (if ever) I will do the mount vs.
OTA offset alignment and then drift align. Too much work for my current use.

Frank


--- In orion-telescopes@yahoogroups.com, "g2baraff" <g2baraff@...> wrote:
>
> Hi Frank
>
> Something YOU can help me with.
>
> Had a look at your web page of home built scopes.  (You're a kluger after my
own heart. Must be the Jersey style.)  Anyhow, you're using a Meade mount that
is generically similar to a Meade mount I just bought off the Mart.
>
> Question has to do with the use of the Polar Alignemtn scope.  (I'll probably
never have occasion to actually use mine, but I have a need to know.)    Looks
like we both have the model with the LED illuminated reticle.
>
> My reticle target shows the position of five stars.  Four of those form a
small quadrilateral, indicating the position of the four brightest stars near
the South Celestial Pole (SCP).
>
> The fifth shows the position of Polaris, correctly spaced from the NCP, whose
position is indicated by a cross at the center of the FOV.
>
> Usage:  Presumably, your polar axis will be aligned with the SCP when you aim
your mount and rotate the Polar Alignment scope so that those four stars are on
their reticle targets.   Good for the Aussies and the Kiwi's.
>
> Presumably, your polar axis will be aligned with the NCP when you aim your
mount and rotate your Polar Alignemtn scope so that Polaris is on its reticle
target.
>
> Qeustion:  How the deuce do you know where to rotate your PA scope to?  That
part doesn't work itself.
>
> Gene
>

Thank you, Wayne, that rule of thumb seems to hold with both the 5" f/9 and the
6" f/8 refractors vs. my 6 inch and 8 inch Newts, while the 10" Dob is clearly
superior to all the smaller scopes.

Perseus is like my first love - nearly a year before I built and looked through
my first telescope I chased Comet Holmes with my cameras, taking hundreds of
photographs of Perseus in the process, growing to appreciate it. I never tire of
seeing it fill the eyepiece.

http://www.photoastronomy.com/cholmes/

The big difference, of course, is that I see my first love in my mind's eye the
way she was 45 years ago, not as the 62-year-old woman she is now. Perseus would
not change visibly in that period of time, would it?

Frank

http://www.telesc0pe.com


--- In orion-telescopes@yahoogroups.com, "WayneG." <im66skidoo@...> wrote:
>
> tincanandstring wrote:
> >  I can't help making comparisons, views through the 6 inch f/9 refractor
seem about the same as the 8 inch f/5 Newt.
> >
>
> WG:  Frank, the oft-spoken general formula that I will repeat here for
> those who might not be familiar with it is that if one subtracts the
> diameter of a scope's central obstruction from its aperture, that will
> give you an idea of how its image contrast (what I assume you saw as
> being about the same) will compare with an unobstructed telescope.
>
> Assuming your 8" has roughly a 2" CO, that might make it compare
> favorably in contrast transfer to a 6.X" refractor.
>
> The fudge factor is how much the scopes lose through differences in
> coatings, wavefront errors and defocused color.
>
> I also share your love of the constellation Perseus;  something about it
> has always attracted me with its long chains of delicately sprinkled
> stars.  Perseus has the distinction of being associated with the most
> other constellations in the sky, including Andromeda, Cassiopeia,
> Cepheus, and Cetus.
>
> The Perseus Asterism you mention, I assume you refer to the rich cluster
> of stars around Mirfak;  that group of stars is no chance coincidence--
> over 100 of the stars seen there are all associated together in what is
> called the Alpha Persei Moving Group.
>
> http://en.wikipedia.org/wiki/Stellar_kinematics
>
> WayneG
>

tincanandstring wrote:
>
> I would love to have a machine shop like Wayne seems to have in order to make
things look great, but that's never going to happen.

WG:  Why?  You can get many nice 7X10 mini mill/drill-lathes for just a
few hundred dollars on eBay and they sit right on a bench.  Never say
never.  Not that you necessarily need a machine shop to make your own stuff.


> Just gotta make do, and have as much fun as possible.
>
> Some people seem to forget it's a hobby, even when money is tight.

WG:  That's the joy and value of ATM, which is what you are basically
doing now.  Something which is lost on too many new people getting into
the hobby now.  It has always been an economic issue, making it
yourself, but it is also much more than that.  It is really an essential
process in /learning/ the hobby, understanding the parts, their
function, etc.

A large part of why these yahoo groups exist and why so many people are
on them is because they don't have that structure which was once a given
in the hobby, several decades ago.  There was no Internet then, you
either learned on your own or you sank.  At best you joined a local club
if you could and worked as a group grinding your own mirrors or
fabricating mounts for yourself or the club.

That was the core of the hobby.

Another reason why I urge many people to seek out the book:  Sam Browns
All About Telescopes, to get a flavor for all the things covered there
that are lost on people these days, even in astronomy clubs.

The only reason why I have the machine shop I have is because at one
time I had a small business on the side geared towards custom
astronomical work.

If the eyepiece is half the telescope, then half the fun of astronomy is
actually making, fixing, modifying or repairing your own gear yourself.
That way, clear or cloudy, day or night, there is always something to do.

Far more reward, satisfaction and learning in doing as much as you can
yourself, rather than just taking it out of a box.  And usually /better/
too, even if it isn't as high-tech.

Plywood or machined 6061-T6 aluminum, anything is better than plastic!

WayneG

WayneG. wrote:
> Another reason why I urge many people to seek out the book:  Sam Browns
> All About Telescopes, to get a flavor for all the things covered there
> that are lost on people these days, even in astronomy clubs.

My first telescope was an Edmund 4.25" "Palomar Jr." Newtonian, which
came with an instruction manual written and illustrated by Sam Brown.
It taught me how to use an equatorial mount, and how to observe things
right way up in a Newtonian.  I later bought a number of his other books
from Edmund, but they disappeared over the years.  When I got back into
astronomy in 1997, one of my first purchases was the current edition of
All About Telescopes, which incorporates a lot of his stuff from back in
the '50s.  Just great stuff -- I read it over and over and always learn
something new (or old, as the case may be).

Geoff

--
Geoff Gaherty
Foxmead Observatory
Coldwater, Ontario, Canada
http://www.gaherty.ca

--- In orion-telescopes@yahoogroups.com, Tim Kamel <timonium27@...> wrote:
>
> Gene,
>
> I only know of two Meade mounts that require a polar alignment scope, the
LXD-55 and the LXD 75.  Your description of the PAS reticle is exactly as on my
LXD-75.  The problem with this mount is that it does not have a pointer and
date circle, the way its look alike Vixen, and other mounts, does.  So there is
no resident way to set a date and time so that you would know where true
north is compared to Polaris. 
>
>                  ********************
>
Thank you Tim.  That's a perfect description of the problem (my mount is the
LX-55) and a perfect (and understandable) description of the solution.

Gene

Question:

How can you tell the difference between field curvature and coma in an eyepiece?

Donnie

Joseph Rome wrote:
> Just because you have to stand on your head and electric current runs
> backwards down there remember the bad news is that all changes when
> you apply a camera to astronomy you must to be very close to proper
> polar alignment, and then still need a guide scope to get good images.

WG:  One program I have enjoyed for years to aid in getting critical
polar alignment is:

http://myastroimages.com/Polar_FinderScope_by_Jason_Dale/

WayneG

dg869500 wrote:
> Question:
>
> How can you tell the difference between field curvature and coma in an
eyepiece?
>

WG:  Coma:  stars at the outer edge will all look like little comets
pointing away from the center.  Comets get bigger as you get closer to edge.

Curvature:  Focal plane not flat.  When stars at middle are sharp, outer
stars out of focus.  When you focus on outer stars, middle ones now blurry.

Sent from my Verizon Wireless BlackBerry

Any chance one of you guys could change the background colors back to something
more readable?

I may be alone on this, but I sort of feel that I'm working too hard to tease
the text out of some of the newly redocarated backgrounds.  It's the CaK purple
that does me in the worst.  (The designation "CaK" was meant to describe a
color, not a barnyard sound.)

AM I alone?

Gene

--- In orion-telescopes@yahoogroups.com, "g2baraff" <g2baraff@...> wrote:
>
> Any chance one of you guys could change the background colors back to
something more readable?
>
> I may be alone on this, but I sort of feel that I'm working too hard to tease
the text out of some of the newly redocarated backgrounds.  It's the CaK purple
that does me in the worst.

WG:  Dear Gene,

Hadn't seen any readability issues, but I changed two of the colors, the
backdrop from a deep Indigo to Lilac, and one other.  This should help.

WayneG

Derek william wrote:

> I'm thinking about purchasing an Orion 8mm Sratus to along with the
> XT8. Has anybody had any good experiences with these ep's? Being that
> it has eight elements, will I lose a noticible amount of contrast and
> resolution when observing the planets such as observing the cloud
> belts of Jupiter? Thanks

WG:  I've heard nothing but accolades about the Stratus from everyone
who has tried them Derek, and while coating technology has gotten to the
point where 9-element designs like the Ethos can have cutting edge
performance, you still always lose /something/ with every extra lens or
air/glass surface.

How much contrast loss is there depends on what you compare them to.
Compared to the best 3-4 element designs, the difference is barely
noticeable to very significant depending on the skill of the observer,
but whether it is worth special eyepieces just for viewing the planets
will depend on the user.

Regards,

WayneG

Derek:

I have the full set of Baader eyepieces and am  very pleased.  At the price they
are hard to beat.  They work well in everything from the Orion 130ST to my C8.

David B

--- In orion-telescopes@yahoogroups.com, derekwil22000@... wrote:
>
> Thanks Donnie, I didn't even consider the baader type ep's. There even 20$
cheaper than the Stratus.
> Sent from my Verizon Wireless BlackBerry
>
> -----Original Message-----
> From: Donnie Garrett <cfzepp@...>
> Date: Mon, 23 Nov 2009 16:25:52
> To: <orion-telescopes@yahoogroups.com>
> Subject: Re: [orion-telescopes] Orion Sratus?
>
> Derek,:
> I have the Baader Hyperion 24, 17 and 13mm eyepieces.  They are nearly
> identical to the Orion Stratus series.... My Baaders's are very nice for the
> price.  Great contrast and a nice 68� field of view.  My first Hyperion was
> a 24mm and I used it in my Orion xt8i dob and it worked wonderful.  Provided
> a wonder wide field view.
>
> Donnie
>
>
> On Mon, Nov 23, 2009 at 4:02 PM, Derek william <derekwil22000@...>wrote:
>
> >
> >
> >   I'm thinking about purchasing an Orion 8mm Sratus to along with the XT8.
> > Has anybody had any good experiences with these ep's? Being that it has
> > eight elements, will I lose a noticible amount of contrast and resolution
> > when observing the planets such as observing the cloud belts of Jupiter?
> > Thanks
> >
> > Derek,
> > NC
> >
> >
> >
>

Don't see this "Classic Background" as being more readable.   Gene has raised a
point if others have a issues with Wayne getting creative speak up but I kind of
like the the changing looks. Pending some feed back I think we will go back to
Wayne's colors.

David B.

--- In orion-telescopes@yahoogroups.com, "missyy9" <im66skidoo@...> wrote:
>
>
>
>
>
> --- In orion-telescopes@yahoogroups.com, "g2baraff" <g2baraff@> wrote:
> >
> > Any chance one of you guys could change the background colors back to
something more readable?
> >
> > I may be alone on this, but I sort of feel that I'm working too hard to
tease the text out of some of the newly redocarated backgrounds.  It's the CaK
purple that does me in the worst.
>
> WG:  Dear Gene,
>
> Hadn't seen any readability issues, but I changed two of the colors, the
backdrop from a deep Indigo to Lilac, and one other.  This should help.
>
> WayneG
>

Derek william wrote:
>
>
> Thanks guys.  I'm going to see about purchasing the Baader 8mm as an
> early xmas gift. I currently have the Meade 14mm UWA, Meade 5.5mm
> and the standard 25 and 10mm ep that came with the scope. So I'm sure
> this 8mm will hit that certain sweet spot I'm looking for in planetary
> viewing at 150X. thanks again folks

I find 150x too low a magnification for planetary observing.  I normally
use 200 to 250x on Jupiter, and 250x to 300x on Mars and Saturn, with
telescopes from 8" to 12" aperture.

I recently tested an Orion Edge-On Planetary 5mm, and _really_ like this
eyepiece, even more than my Tele Vue Radian 5mm that cost twice as much.

Geoff

--
Geoff Gaherty
Foxmead Observatory
Coldwater, Ontario, Canada
http://www.gaherty.ca

Geoff, you are certainly accurate in pointing out that 200x and up makes
planetary viewing much more interesting, but I find that those powers are
annoying with a pushed scope and much better used with a scope that can be RA or
Alt-Az tracking driven.

As much as I like my Dobs, and the 10" in particular, I can concentrate better
with the planet centered in the EP, this takes a powered mount, like both of
your big ones.

Last Spring, I was able to successfully exceed 300x on Saturn a few times, but
it took the CG-5 with the C8 or C8-N to keep it viewable.


--- In orion-telescopes@yahoogroups.com, Geoff Gaherty <geoff@...> wrote:
>
>
> I find 150x too low a magnification for planetary observing.  I normally
> use 200 to 250x on Jupiter, and 250x to 300x on Mars and Saturn, with
> telescopes from 8" to 12" aperture.
>
> I recently tested an Orion Edge-On Planetary 5mm, and _really_ like this
> eyepiece, even more than my Tele Vue Radian 5mm that cost twice as much.
>
> Geoff
>
> --
> Geoff Gaherty
> Foxmead Observatory
> Coldwater, Ontario, Canada
> http://www.gaherty.ca
>

tincanandstring wrote:
>
>
>
> Geoff, you are certainly accurate in pointing out that 200x and up makes
> planetary viewing much more interesting, but I find that those powers
> are annoying with a pushed scope and much better used with a scope that
> can be RA or Alt-Az tracking driven.
>
> As much as I like my Dobs, and the 10" in particular, I can concentrate
> better with the planet centered in the EP, this takes a powered mount,
> like both of your big ones.
>
> Last Spring, I was able to successfully exceed 300x on Saturn a few
> times, but it took the CG-5 with the C8 or C8-N to keep it viewable.

For several years my main scope was a 10" Meade Dob (old sonotube
version) with no drive, and my most used magnification for lunar and
planetary observation was 285x.  The only time it bothered me was in
timing occultations, where I was always afraid the occultation would
occur just as I was moving the scope.  Otherwise, I'd reset the planet
to the edge of the field and let it drift across.

Geoff

--
Geoff Gaherty
Foxmead Observatory
Coldwater, Ontario, Canada
http://www.gaherty.ca

You're telling me I need more practice and patience. I'm sure you're right.

--- In orion-telescopes@yahoogroups.com, Geoff Gaherty <geoff@...> wrote:
>
> For several years my main scope was a 10" Meade Dob (old sonotube
> version) with no drive, and my most used magnification for lunar and
> planetary observation was 285x.  The only time it bothered me was in
> timing occultations, where I was always afraid the occultation would
> occur just as I was moving the scope.  Otherwise, I'd reset the planet
> to the edge of the field and let it drift across.
>
> Geoff
>
> --
> Geoff Gaherty
> Foxmead Observatory
> Coldwater, Ontario, Canada
> http://www.gaherty.ca
>

The long drawtube of the focuser I used on the 127mm f/9 refractor vignettes
when I use 2 inch eyepieces, so I use only 1.25 inch EPs at this time.

I have the 20mm and 9mm 66 degree wide made by Synta and sold as the Orion
Expanse as well as others. In fast Newts, the edges are fuzzy, certainly made
worse by the coma of the scope itself. On SCTs, the field curvature also affects
the edges.

But on the f/9 refractor, the views are outstanding. The 20 is my EP of choice
for general searching, the 9mm goes in when I am in the area I want to observe
deeper. So far, the seeing has been such that the resulting 127x is the limit of
comfortable viewing many nights, anyway.

I also have an 11mm 80 degree wide, manufacturer unknown, and it looks OK here,
but I haven't spent much time with it. When I view an object a bit large for the
9mm I have used it with good results.

The series I have used least so far is the Orion ED-2. I have a 22mm and a 14mm,
Orion says the advantage of ED glass in an eyepiece is longer eye relief. I find
them sharp and they seem well polished, no glows around bright objects. The 14mm
looked great used with the TeleVue 1.8 Barlow the other night, the first time I
have seen both Theta Orionis E and F in a scope smaller than 8 inches of
aperture.

Photos of these and links to suppliers are in the middle of this page -
http://www.telesc0pe.com/t2b.htm

I hope eventually to try more of the 50+ eyepieces I now have, it is clear that
they perform differently in different scopes. I hope to group them for different
applications, there is no point in hauling all or even most of them out every
time.

I know that some would say that I would have been better off by simply investing
in a range of better eyepieces from the beginning, but I keep a scope in the
car, one in my truck at work, I have a few in Asia, and I sometimes set up
multiples at home. I enjoy experimenting with various eyepieces and noting the
differences between them. Besides, I am a klutz and would rather drop a $30 ebay
ultrawide than a $$$ anything.

I wonder how Wayne decides which EP to use in any given situation? (I have seen
those photos of some of his collection.)

Frank

http://www.telesc0pe.com/

tincanandstring wrote:
>
> I hope eventually to try more of the 50+ eyepieces I now have, it is
> clear that they perform differently in different scopes. I hope to group
> them for different applications, there is no point in hauling all or
> even most of them out every time.
>
> I know that some would say that I would have been better off by simply
> investing in a range of better eyepieces from the beginning, but I keep
> a scope in the car, one in my truck at work, I have a few in Asia, and I
> sometimes set up multiples at home. I enjoy experimenting with various
> eyepieces and noting the differences between them. Besides, I am a klutz
> and would rather drop a $30 ebay ultrawide than a $$$ anything.

Many years ago I studied nature photography with Freeman Patterson, and
one of the things I learned was to keep my equipment simple.  In fact
for a couple of decades I rarely used anything but an 85mm f/2 lens on
my SLR.  I've applied this same KISS principle to my astronomy eyepieces
and rarely use more than two or three eyepieces on a particular
telescope.  I've found using high quality wide field eyepieces helps
with this.  For many years I used mainly a 22mm Nagler (63x) and 8.8mm
Meade Ultra Wide (157x) in my 11" Starmaster Newtonian, plus a pair of
10mm Antares Pl�ssls (240x) in my binoviewer.  Nowadays with my 11"
Celestron SCT I use a 40mm UO MK-70 (70x), 16mm Nagler (175x), and 11mm
Nagler (255x).  And that's about it.  Mind you, it took me years to
whittle my eyepiece collection down.  I dare say I now have less money
invested in eyepieces than you do!

Geoff

--
Geoff Gaherty
Foxmead Observatory
Coldwater, Ontario, Canada
http://www.gaherty.ca

--- In orion-telescopes@yahoogroups.com, "tincanandstring" <frank@...> wrote:
>
>
> You're telling me I need more practice and patience. I'm sure you're right.
>

No if you want to study the image, without worrying about constantly moving the
scope to keep the image in the eyepiece sweet spot you really do need a driven
equatorial mount

Not just North America.

http://7timer.y234.cn/V3/

Frank

Just released:

The 2.25 pound, iconoclastic TeleVue Ethos 21mm 100� 2-inch 9-element
Tautz-Bertele-like ocular will be shipping to customers in about three
weeks.  As predicted, street price will be between $799 and $849
depending on where you purchase it at, which factors in a "10% off"
discount which seems to be sticking due to the economy, even if it is no
longer touted as a "sale."

Clear Skies,

WayneG