The importance of a good Finder

On my first visit to Antiparos, a year ago, I only carried with me my
11x80. This time I carried my 60mm/700mm Tasco as well, along.

One thing that became apparent as I was browsing through "Turn Left",
besides the Tasco's finder being absolutely useless, (the 5x15 finder
consists of two lenses, and after unscrewing the main lens, I saw that
it was stopped down to f20 or something such, the actual hole was 5mm!
(no wonder since the main finder lens consists of one element, so it had
to be made achromatic)), was the importance of having a good finder.

I spent half of my time searching through known M objects, trying to
locate them through the Tasco. After being located, the T did a good job
overall, but trying to find less bright objects, such as some of the
NGC's in Cass, proved to be a mazochistic torture.

One month ago, I looked through my neighbour's Meade 125ETX/EC, and its
finder was almost as useless. We spent most our time trying to locate
the objects. Goto was not available, so we tried the Equatorial mounting
and after aligning, even locating M31 was a pain in the butt, trying to
not de-align the mount. From the Athenian sky, M31 was _not_ visible in
the finder. Go figure...

For practical reasons, I don't think that aligning giant binos with a
small telescope is very usable, particularly since the field of view of
my 11x80 is very big compared to that of the Tasco.

But I think that even a badly aligned good finder would sure beat a no
finder, at all.

Knowing that the object is _within_ the field of view of the Tasco,
certainly helps in the identification, even if the object is slightly
off. All that matters is picking it up for the first time.

I am thinking of aligning the Tasco with the 11x80, using the same
tripod, where both scopes can be screwed against a horizontal truss,
which in turn can be screwed against my tripod:

O-O O
|-----|
|
+
/ \

The Tasco doesn't have any clamp rings however, so I'd have to unscrew
these horrible side screws, and ask my engineer to either design two
tube clamps or two rings with screws.

The rings with screws are these where the ring is larger than the tube,
the scope slides through and there are 3 screws which provide for
micrometric adjustment, similar to those found on finders.

If I use tube clamps, I lose any micrometric adjustments, so I don't
know how I can do the alignment, particularly since the entire thing
needs to be disassembled during the trips.

If I use rings with screws, the screws will have to screw against the
Tasco tube itself, possibly damaging it. So I get micrometric alignment,
but I also get scratches and dents on the tube.

Anybody has any better ideas on how I can better align these two?

The 11x80 already has a screw in support for the tripod as it is, so the
only thing that needs to be done is extend the base truss and tell my
engineer what to do for the Tasco tube.

Thanks much in advance, and happy observing!
--
Ioannis
http://users.forthnet.gr/ath/jgal/
___________________________________________
Eventually, _everything_ is understandable.

I know that some folks really like an optical finder, but I have found that
a 1x finder (I like the Rigel Quickfinder) coupled with a low-power
wide-field eyepiece works for me.

Dennis

"Ioannis" wrote in message
...
On my first visit to Antiparos, a year ago, I only carried with me my
11x80. This time I carried my 60mm/700mm Tasco as well, along.

One thing that became apparent as I was browsing through "Turn Left",
besides the Tasco's finder being absolutely useless, (the 5x15 finder
consists of two lenses, and after unscrewing the main lens, I saw that
it was stopped down to f20 or something such, the actual hole was 5mm!
(no wonder since the main finder lens consists of one element, so it had
to be made achromatic)), was the importance of having a good finder.

I spent half of my time searching through known M objects, trying to
locate them through the Tasco. After being located, the T did a good job
overall, but trying to find less bright objects, such as some of the
NGC's in Cass, proved to be a mazochistic torture.

One month ago, I looked through my neighbour's Meade 125ETX/EC, and its
finder was almost as useless. We spent most our time trying to locate
the objects. Goto was not available, so we tried the Equatorial mounting
and after aligning, even locating M31 was a pain in the butt, trying to
not de-align the mount. From the Athenian sky, M31 was _not_ visible in
the finder. Go figure...

For practical reasons, I don't think that aligning giant binos with a
small telescope is very usable, particularly since the field of view of
my 11x80 is very big compared to that of the Tasco.

But I think that even a badly aligned good finder would sure beat a no
finder, at all.

Knowing that the object is _within_ the field of view of the Tasco,
certainly helps in the identification, even if the object is slightly
off. All that matters is picking it up for the first time.

I am thinking of aligning the Tasco with the 11x80, using the same
tripod, where both scopes can be screwed against a horizontal truss,
which in turn can be screwed against my tripod:

O-O O
|-----|
|
+
/ \

The Tasco doesn't have any clamp rings however, so I'd have to unscrew
these horrible side screws, and ask my engineer to either design two
tube clamps or two rings with screws.

The rings with screws are these where the ring is larger than the tube,
the scope slides through and there are 3 screws which provide for
micrometric adjustment, similar to those found on finders.

If I use tube clamps, I lose any micrometric adjustments, so I don't
know how I can do the alignment, particularly since the entire thing
needs to be disassembled during the trips.

If I use rings with screws, the screws will have to screw against the
Tasco tube itself, possibly damaging it. So I get micrometric alignment,
but I also get scratches and dents on the tube.

Anybody has any better ideas on how I can better align these two?

The 11x80 already has a screw in support for the tripod as it is, so the
only thing that needs to be done is extend the base truss and tell my
engineer what to do for the Tasco tube.

Thanks much in advance, and happy observing!
--
Ioannis
http://users.forthnet.gr/ath/jgal/
___________________________________________
Eventually, _everything_ is understandable.

What diameter of finderscope will fit into the present finder mount on the
Tasco?

There are some pretty good 5x25 finders in existence, such as the one that
used to come with the Celestron 5.

I'm one of the people who use and enjoy the optical finder. I had a Telrad
and found it to be worthwhile but not under the light polluted skies in my
area. With no magnification, you couldn't see many of the sign post stars,
making it very difficult to starhop. On the other hand, the 50 or 60mm
finder will allow you to see many of these stars which would otherwise be
invisible. But here is a question I have regarding finders to which I never
had an answer that made any sense...

I use a 50mm straight through finder on both of my SCTs. What I usually do
(and I find this very natural) is view through the finder with one eye and
view where I want to go with the other (in other words I keep both eyes
open). While you're doing this, your brain reports a dual image until you
have lined up the scope with the star you were looking at with the unaided
eye. I could usually manually slew the scope to the new location in
seconds. Now here comes my question: I've seen guys change the finder on
their SCTs from the straight through to the finder with a built in 90 degree
diagonal. What is the benefit in doing this? Of course, I could understand
doing this with a Dob, but why do it with an SCT or a refractor?

Al


"Dennis Woos" wrote in message
...
I know that some folks really like an optical finder, but I have found
that
a 1x finder (I like the Rigel Quickfinder) coupled with a low-power
wide-field eyepiece works for me.

Dennis

"Ioannis" wrote in message
...
On my first visit to Antiparos, a year ago, I only carried with me my
11x80. This time I carried my 60mm/700mm Tasco as well, along.

One thing that became apparent as I was browsing through "Turn Left",
besides the Tasco's finder being absolutely useless, (the 5x15 finder
consists of two lenses, and after unscrewing the main lens, I saw that
it was stopped down to f20 or something such, the actual hole was 5mm!
(no wonder since the main finder lens consists of one element, so it had
to be made achromatic)), was the importance of having a good finder.

I spent half of my time searching through known M objects, trying to
locate them through the Tasco. After being located, the T did a good job
overall, but trying to find less bright objects, such as some of the
NGC's in Cass, proved to be a mazochistic torture.

One month ago, I looked through my neighbour's Meade 125ETX/EC, and its
finder was almost as useless. We spent most our time trying to locate
the objects. Goto was not available, so we tried the Equatorial mounting
and after aligning, even locating M31 was a pain in the butt, trying to
not de-align the mount. From the Athenian sky, M31 was _not_ visible in
the finder. Go figure...

For practical reasons, I don't think that aligning giant binos with a
small telescope is very usable, particularly since the field of view of
my 11x80 is very big compared to that of the Tasco.

But I think that even a badly aligned good finder would sure beat a no
finder, at all.

Knowing that the object is _within_ the field of view of the Tasco,
certainly helps in the identification, even if the object is slightly
off. All that matters is picking it up for the first time.

I am thinking of aligning the Tasco with the 11x80, using the same
tripod, where both scopes can be screwed against a horizontal truss,
which in turn can be screwed against my tripod:

O-O O
|-----|
|
+
/ \

The Tasco doesn't have any clamp rings however, so I'd have to unscrew
these horrible side screws, and ask my engineer to either design two
tube clamps or two rings with screws.

The rings with screws are these where the ring is larger than the tube,
the scope slides through and there are 3 screws which provide for
micrometric adjustment, similar to those found on finders.

If I use tube clamps, I lose any micrometric adjustments, so I don't
know how I can do the alignment, particularly since the entire thing
needs to be disassembled during the trips.

If I use rings with screws, the screws will have to screw against the
Tasco tube itself, possibly damaging it. So I get micrometric alignment,
but I also get scratches and dents on the tube.

Anybody has any better ideas on how I can better align these two?

The 11x80 already has a screw in support for the tripod as it is, so the
only thing that needs to be done is extend the base truss and tell my
engineer what to do for the Tasco tube.

Thanks much in advance, and happy observing!
--
Ioannis
http://users.forthnet.gr/ath/jgal/
___________________________________________
Eventually, _everything_ is understandable.

Al,
If someone puts on a right angle, correct image (RACI) finder, they get an
image that matches their charts. If it's just RA, maybe they mount it low
enough it's hard to get behind when pointed high in the sky.

I've got a straight through on my SCT and a normal RA on my Dob and I find
I'm handicapped by an erect image. I'm so accustomed to the image reversal,
I can't move the scope where I want!

HAve fun,
Frank

"Al" wrote in message
t...
.... Now here comes my question: I've seen guys change the finder on
their SCTs from the straight through to the finder with a built in 90
degree
diagonal. What is the benefit in doing this? Of course, I could
understand
doing this with a Dob, but why do it with an SCT or a refractor?

Al

I use a red dot pointer to find a "starting star" with my C8 SCT, and
then a right angle 50mm finder to starhop to my target. The right angle
is simply to give me a more comfortable angle to look through the
thing... no way could I screw myself under the scope to look toward the
zenith without it. I don't have too much trouble flipping the view to
fit my charts, but someday I may break down and get one of those fancy
correct image thingys.
Marty

Thanks for responding, Frank!

Al


"Frank Bov" wrote in message
...
Al,
If someone puts on a right angle, correct image (RACI) finder, they get an
image that matches their charts. If it's just RA, maybe they mount it low
enough it's hard to get behind when pointed high in the sky.

I've got a straight through on my SCT and a normal RA on my Dob and I find
I'm handicapped by an erect image. I'm so accustomed to the image
reversal,
I can't move the scope where I want!

HAve fun,
Frank

"Al" wrote in message
t...
... Now here comes my question: I've seen guys change the finder on
their SCTs from the straight through to the finder with a built in 90
degree
diagonal. What is the benefit in doing this? Of course, I could
understand
doing this with a Dob, but why do it with an SCT or a refractor?

Al

Just busy . . .

"Bill Becker" wrote in message
...
Good to see ya back, Frank. Where you been?

Best regards,
Bill