Star hopping with inverted or mirror images

I want to buy a telescope, which I will use for star hopping to find
DSOs. I plan to use about 60x or less to find my object then change
eyepieces or use a Barlow to see more detail.

My budget for this (including accessories such as dew shields and
tripods) is $2000.

Are there reflectors or refractors or other types of scopes that
correct the image so you can follow stars exactly as they are shown in
an atlas? Or are there atlases that show stars inverted or with a
mirror image that corresponds to what you see in the eyepiece?

Can prisms or additional lenses be placed in the light path to give a
right reading image? (If Jupiter had JUPITER written on its face, I do
not want to see RETIPUJ when looking at it!).

Also, are there websites (or books) that describe this type of thing.
If so, please list several.

Thanks

On 9 Aug 2005 07:13:28 -0700, callisto wrote:


Or are there atlases that show stars inverted or with a
mirror image that corresponds to what you see in the eyepiece?


Flip the page 180 degrees to your line of sight. . .voila.




--
Martin R. Howell
"Photographs From the Universe of Amateur Astronomy"
http://members.isp.com/universeofama...nomy%40isp.com

On 9 Aug 2005 07:13:28 -0700, "callisto"
wrote:

Are there reflectors or refractors or other types of scopes that
correct the image so you can follow stars exactly as they are shown in
an atlas? Or are there atlases that show stars inverted or with a
mirror image that corresponds to what you see in the eyepiece?

With a newtonian you can always turn the star chart so that the
eyepiece view matches the chart. The writing might be upside down,
but the stars are in the right places. The rule is that with an even
number of reflections you can make the image in the eyepiece match the
chart by turning the chart. When you have an odd number of
reflections as in a refractor with a plain diagonal (one reflection)
or in an SCT with a plain diagonal (three reflections) the eyepiece
view is mirror reversed and you can't match the chart to the eyepiece
no matter how you turn the chart. You can mentally translate left for
right when you look at the chart. This is not hard to do. Image
erecting diagonals add an extra reflection so you get an even number
of reflections and the image is no longer flipped left-right. The
image is not quite as bright because of the extra reflection and you
get a diffraction spike from the roof of the prism. I have an amici
prism in my right ange finder but a plain diagonal prism for the large
telescope.

Things in the sky change orientation during the night. From my back
yard Orion's head is to the left when he is rising. When Orion is
setting his head is to the right. You always need to turn the chart
to match the view.

Hi, Star hopping is the way you had to do it before computers! Like black
and white TV before Color and Stick Shift before Automatic transmission!
Every professional telescope in the world is now motorized and GOTO.
Even the department store cheapie scopes are GOTO. Why do you want to spend
most of your time searching and trying to figure out which way is up?
In reality you learn much more about the sky with a GOTO system than you can
ever learn with a chart in one hand, a flashlight in another hand and your
brain trying to remember which way is left and right or up and down.
With a $2000 budget you can get a very nice MODERN scope with a built in
computer that can tell you everything you want to know about any object in
the heavens. You can point anywhere and it will tell you all about the
object in your field of view. You can request any object and it will take
you there. You can ask it to take you on a tour of the most interesting
objects currently in view. It is great and you can see many more objects
that you ever can in a night of push and pull. When ever I am viewing near
push-pullers they are constantly running over and asking be to slew to an
object they are having trouble finding. Then they can look at the angle of
my OTA to see where to point their tube. Someone with a green lazer is
really popular because then the P-P people can see it point right to the
object of their search.
I know this will bring out all the dobbers and push-pullers to rebut what I
have said. Most can't understand how to use the new equipment so pretend
they are happy. I know that once you have learned the old ways you hate to
change to something new. That is why young kids adopt and learn new
technology very easily while the old timers prefer to stick with what they
learned when they were young. Some of us old timers, yes, I am 70 years
old, do like to adopt new methods and technology. I have 5 or 6 scopes and
they are all GOTO systems. Some by Meade and some by Celestron. A Celestron
Advanced Series scope would be well within your budget and a very satisfying
setup to use.
I have a Meade LX200GPS which is at the top end of your budget but is
pleasure to use. Some will tell you there are all sorts of problems with
the new fangled stuff but I think they probably have trouble with anything
new. I have had many GOTO systems for several years and have never had a
problem or failure with any of them.
I am not here to talk you into doing anything my way, only to give you an
alternative to think about. It won't be long before star hopping will be
something you read about in the history books. You don't want to be stuck
with expensive obsolete equipment!
Good Luck and stand back for the barrage!
"callisto" wrote in message
ups.com...
I want to buy a telescope, which I will use for star hopping to find
DSOs. I plan to use about 60x or less to find my object then change
eyepieces or use a Barlow to see more detail.

My budget for this (including accessories such as dew shields and
tripods) is $2000.

Are there reflectors or refractors or other types of scopes that
correct the image so you can follow stars exactly as they are shown in
an atlas? Or are there atlases that show stars inverted or with a
mirror image that corresponds to what you see in the eyepiece?

Can prisms or additional lenses be placed in the light path to give a
right reading image? (If Jupiter had JUPITER written on its face, I do
not want to see RETIPUJ when looking at it!).

Also, are there websites (or books) that describe this type of thing.
If so, please list several.

Thanks

Duke wrote:
Hi, Star hopping is the way you had to do it before computers! Like black
and white TV before Color and Stick Shift before Automatic transmission!
Every professional telescope in the world is now motorized and GOTO.
[ ... ]

Oh no, Not AGAIN!!! :-/

Here goes the thread in flames...

- Alex

Yup. I can smell the napalm already. ^_^

But seriously, the more you do star hopping, the more you get used to flipping
the images around in your head to match the map projections, but it does require
time, usually a lot of time practicing it as the telescope, which is why a lot
of us did this when we were young, in our backyards or whatever, to maximize the
practice time.

This is actually a great general rule. Practice at home, as often as you can.
If you can eliminate any effects of lights that shine directly on you you'd be
surprised at how many stars you can see from suburban locations. Eliminating
the glow from lights that don't shine on you improves it still further. Nothing
like a dark site of course, but much better than you think. This applies to any
new technique OR equipment. Get used to the technique and equipment when you
don't have to use a flashlight to see anything. You might not see the object,
but it'll give you practice in adjusting those images through the telescope to
match the maps.

Select a telescope where you just have to flip the page around to match the
view. Eases the task of practicing.

--- Dave
--
----------------------------------------------------------------------
Pinprick holes in a colorless sky
Let inspired figures of light pass by
The Mighty Light of ten thousand suns
Challenges infinity, and is soon gone




"Alexander Avtanski" wrote in message
...
Duke wrote:
Hi, Star hopping is the way you had to do it before computers! Like black
and white TV before Color and Stick Shift before Automatic transmission!
Every professional telescope in the world is now motorized and GOTO.
[ ... ]

Oh no, Not AGAIN!!! :-/

Here goes the thread in flames...

- Alex

Cartes du ciel and HNSky and probably other star chart software have
flip horizontal/flip vertical functions - so keep the technology in
your computer, not your telescope

Duke wrote:
[tripe deleted]

Dear Troll,

Thank you for your troll. Your troll has been evaluated by
our panel of experts. Here are the results of our tests.

We found that your troll was...
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You could improve your troll considerably by...
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Please get a...
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You should...
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Suggested other activities besides trolling...
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You have...
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"William Hamblen" wrote in message
...
The rule is that with an even
number of reflections you can make the image in the eyepiece match the
chart by turning the chart. When you have an odd number of
reflections as in a refractor with a plain diagonal (one reflection)
or in an SCT with a plain diagonal (three reflections) the eyepiece
view is mirror reversed and you can't match the chart to the eyepiece
no matter how you turn the chart.

What would you get with a refractor with two diagonals, such that the light
path would come from(say) a star on the right, get reflected vertically
upwards, and then get reflected at 90 degrees to the plane formed by the
first two sections of the path?

The reason I'm asking is I hope the answer is such that I could make a
finder with two such diagonals and see in it what I see in a newtonian...

On Tue, 9 Aug 2005 21:42:28 -0300, "jtaylor"
wrote:

What would you get with a refractor with two diagonals, such that the light
path would come from(say) a star on the right, get reflected vertically
upwards, and then get reflected at 90 degrees to the plane formed by the
first two sections of the path?

You would get a correct image. The second diagonal adds a lot of
length. You would need to cut down the tube of the finder by the same
amount or else you couldn't focus. The edge of the front diagonal
probably would cause vignetting.