6" or 8" and what focal ratio?

I'm a relative newbie to astronomy, though I've held a long fascination
with it since I was a kid. To fuel my fascination I'm looking to get a
fairly decent telescope, which will need to be a good 'all round' scope.

A friend highly recommended Orion Optics UK (www.orionoptics.co.uk) who
seem to have some nice equipment. From the searches I've done, Orion
Optics UK seem to get a good reputation over here and the factory is
relatively local to me, which is a bonus.

The problem is, I'm looking at their Europa range but can't decide on
the 6" or the 8". I appreciate that aperture is king, but for general
(newbie) observation of the moon, planets and some deep sky stuff, how
much would I really be missing if I got the 6" in preference to the 8".
I will need reasonable portability too so I can get to a dark site as I
live in some light pollution!! Are there any good websites that show
pictures of comparisons between different aperture telescopes on the
same object?

I know how an equatorial mount works in principle, but what is the
difference in an EQ3 mount (on the 6") and an EQ5 mount (on the 8")? If
I get the motor drive should I go for the dual drive or just the RA
drive? If the telescope is properly aligned, do I really need the dual
drive? Surely the RA should be enough. I need advice from people with
more experience.

And finally, for general use what focal ratio would be best? The 6"
comes in both F5 and F8 varieties and the 8" comes in both F4.4 and F6
varieties.

I'm guessing the consensus will fall on the F6 8".

Andrew

Before you put out any cash to anyone, read the Telescope Buyers FAQ and you'll
be a bit better off.

Telescope Buyers FAQ
http://home.inreach.com/starlord


--
"In this universe the night was falling,the shadows were lengthening
towards an east that would not know another dawn.
But elsewhere the stars were still young and the light of morning
lingered: and along the path he once had followed, man would one day go
again."

Arthur C. Clarke, The City & The Stars

SIAR
www.starlords.org
Freelance Writers Shop
http://www.freelancewrittersshop.netfirms.com
Telescope Buyers FAQ
http://home.inreach.com/starlord

"andrew" wrote in message
...

I'm a relative newbie to astronomy, though I've held a long fascination
with it since I was a kid. To fuel my fascination I'm looking to get a
fairly decent telescope, which will need to be a good 'all round' scope.

A friend highly recommended Orion Optics UK (www.orionoptics.co.uk) who
seem to have some nice equipment. From the searches I've done, Orion
Optics UK seem to get a good reputation over here and the factory is
relatively local to me, which is a bonus.

The problem is, I'm looking at their Europa range but can't decide on
the 6" or the 8". I appreciate that aperture is king, but for general
(newbie) observation of the moon, planets and some deep sky stuff, how
much would I really be missing if I got the 6" in preference to the 8".
I will need reasonable portability too so I can get to a dark site as I
live in some light pollution!! Are there any good websites that show
pictures of comparisons between different aperture telescopes on the
same object?

I know how an equatorial mount works in principle, but what is the
difference in an EQ3 mount (on the 6") and an EQ5 mount (on the 8")? If
I get the motor drive should I go for the dual drive or just the RA
drive? If the telescope is properly aligned, do I really need the dual
drive? Surely the RA should be enough. I need advice from people with
more experience.

And finally, for general use what focal ratio would be best? The 6"
comes in both F5 and F8 varieties and the 8" comes in both F4.4 and F6
varieties.

I'm guessing the consensus will fall on the F6 8".

Andrew


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Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
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Before you put out any cash to anyone, read the Telescope Buyers FAQ and you'll
be a bit better off.

Telescope Buyers FAQ
http://home.inreach.com/starlord


--
"In this universe the night was falling,the shadows were lengthening
towards an east that would not know another dawn.
But elsewhere the stars were still young and the light of morning
lingered: and along the path he once had followed, man would one day go
again."

Arthur C. Clarke, The City & The Stars

SIAR
www.starlords.org
Freelance Writers Shop
http://www.freelancewrittersshop.netfirms.com
Telescope Buyers FAQ
http://home.inreach.com/starlord

"andrew" wrote in message
...

I'm a relative newbie to astronomy, though I've held a long fascination
with it since I was a kid. To fuel my fascination I'm looking to get a
fairly decent telescope, which will need to be a good 'all round' scope.

A friend highly recommended Orion Optics UK (www.orionoptics.co.uk) who
seem to have some nice equipment. From the searches I've done, Orion
Optics UK seem to get a good reputation over here and the factory is
relatively local to me, which is a bonus.

The problem is, I'm looking at their Europa range but can't decide on
the 6" or the 8". I appreciate that aperture is king, but for general
(newbie) observation of the moon, planets and some deep sky stuff, how
much would I really be missing if I got the 6" in preference to the 8".
I will need reasonable portability too so I can get to a dark site as I
live in some light pollution!! Are there any good websites that show
pictures of comparisons between different aperture telescopes on the
same object?

I know how an equatorial mount works in principle, but what is the
difference in an EQ3 mount (on the 6") and an EQ5 mount (on the 8")? If
I get the motor drive should I go for the dual drive or just the RA
drive? If the telescope is properly aligned, do I really need the dual
drive? Surely the RA should be enough. I need advice from people with
more experience.

And finally, for general use what focal ratio would be best? The 6"
comes in both F5 and F8 varieties and the 8" comes in both F4.4 and F6
varieties.

I'm guessing the consensus will fall on the F6 8".

Andrew


---
Outgoing mail is certified Virus Free.
Checked by AVG anti-virus system (http://www.grisoft.com).
Version: 6.0.515 / Virus Database: 313 - Release Date: 9/1/03

Myself spend all your money on size. A newtonian on a DOB mount is
very good beginner scope.
Yo u learn the sky, learn to find objects, save the money from motor
drives and use it to by increased irror size, can you get a 10 inch
scope?

Now on to focal length, the hight the number like f6 has a longer
tube so if the tube length will fit in the transportation vehicle go
with the higher number. With the higher f number you should get great
views with an increase in magnification and go to higher power limits.
I have an 8 inch f7 and it just fits into the car. a 10 inch mirror
will increase light gathering by 50% and more is better!

I know how an equatorial mount works in principle, but what is the
difference in an EQ3 mount (on the 6") and an EQ5 mount (on the 8")? If
I get the motor drive should I go for the dual drive or just the RA
drive? If the telescope is properly aligned, do I really need the dual
drive? Surely the RA should be enough. I need advice from people with
more experience.

And finally, for general use what focal ratio would be best? The 6"
comes in both F5 and F8 varieties and the 8" comes in both F4.4 and F6
varieties.

I'm guessing the consensus will fall on the F6 8".

Andrew

Myself spend all your money on size. A newtonian on a DOB mount is
very good beginner scope.
Yo u learn the sky, learn to find objects, save the money from motor
drives and use it to by increased irror size, can you get a 10 inch
scope?

Now on to focal length, the hight the number like f6 has a longer
tube so if the tube length will fit in the transportation vehicle go
with the higher number. With the higher f number you should get great
views with an increase in magnification and go to higher power limits.
I have an 8 inch f7 and it just fits into the car. a 10 inch mirror
will increase light gathering by 50% and more is better!

I know how an equatorial mount works in principle, but what is the
difference in an EQ3 mount (on the 6") and an EQ5 mount (on the 8")? If
I get the motor drive should I go for the dual drive or just the RA
drive? If the telescope is properly aligned, do I really need the dual
drive? Surely the RA should be enough. I need advice from people with
more experience.

And finally, for general use what focal ratio would be best? The 6"
comes in both F5 and F8 varieties and the 8" comes in both F4.4 and F6
varieties.

I'm guessing the consensus will fall on the F6 8".

Andrew

I'd go for the shorter focal length and the 8 inch, because it makes for
a lighter and more compact telescope. That counts for a lot, unless it's
permanently housed in a shed or something.
I own a 10 inch, but I'm not sure I would buy it as a first telescope -
it might even be my last, because there is so much I haven't seen yet!
If you can afford it, go for dual axis control - you may well jump into
doing photography with a digital camera right away because it's so easy,
and if you go on to do long exposures with film or CCD you'll need fine
control.
And don't forget about money for eyepieces. Good eyepieces are
important, especially if you go for that short focus.
I've cross posted this to uk.sci.astronomy guessing that you're from
here!

In message ,
writes
Myself spend all your money on size. A newtonian on a DOB mount is
very good beginner scope.
Yo u learn the sky, learn to find objects, save the money from motor
drives and use it to by increased irror size, can you get a 10 inch
scope?

Now on to focal length, the hight the number like f6 has a longer
tube so if the tube length will fit in the transportation vehicle go
with the higher number. With the higher f number you should get great
views with an increase in magnification and go to higher power limits.
I have an 8 inch f7 and it just fits into the car. a 10 inch mirror
will increase light gathering by 50% and more is better!




I know how an equatorial mount works in principle, but what is the
difference in an EQ3 mount (on the 6") and an EQ5 mount (on the 8")? If
I get the motor drive should I go for the dual drive or just the RA
drive? If the telescope is properly aligned, do I really need the dual
drive? Surely the RA should be enough. I need advice from people with
more experience.

And finally, for general use what focal ratio would be best? The 6"
comes in both F5 and F8 varieties and the 8" comes in both F4.4 and F6
varieties.

I'm guessing the consensus will fall on the F6 8".

Andrew


--
"Forty millions of miles it was from us, more than forty millions of miles of
void"

I'd go for the shorter focal length and the 8 inch, because it makes for
a lighter and more compact telescope. That counts for a lot, unless it's
permanently housed in a shed or something.
I own a 10 inch, but I'm not sure I would buy it as a first telescope -
it might even be my last, because there is so much I haven't seen yet!
If you can afford it, go for dual axis control - you may well jump into
doing photography with a digital camera right away because it's so easy,
and if you go on to do long exposures with film or CCD you'll need fine
control.
And don't forget about money for eyepieces. Good eyepieces are
important, especially if you go for that short focus.
I've cross posted this to uk.sci.astronomy guessing that you're from
here!

In message ,
writes
Myself spend all your money on size. A newtonian on a DOB mount is
very good beginner scope.
Yo u learn the sky, learn to find objects, save the money from motor
drives and use it to by increased irror size, can you get a 10 inch
scope?

Now on to focal length, the hight the number like f6 has a longer
tube so if the tube length will fit in the transportation vehicle go
with the higher number. With the higher f number you should get great
views with an increase in magnification and go to higher power limits.
I have an 8 inch f7 and it just fits into the car. a 10 inch mirror
will increase light gathering by 50% and more is better!




I know how an equatorial mount works in principle, but what is the
difference in an EQ3 mount (on the 6") and an EQ5 mount (on the 8")? If
I get the motor drive should I go for the dual drive or just the RA
drive? If the telescope is properly aligned, do I really need the dual
drive? Surely the RA should be enough. I need advice from people with
more experience.

And finally, for general use what focal ratio would be best? The 6"
comes in both F5 and F8 varieties and the 8" comes in both F4.4 and F6
varieties.

I'm guessing the consensus will fall on the F6 8".

Andrew


--
"Forty millions of miles it was from us, more than forty millions of miles of
void"

In article , Chris.B
writes

Yes the 10" is a step up in size from the 6" & 8". But there's no
reason why our friend can't get an 8" into his car in the search for
dark skies.

Thanks for the suggestions guys, I'm heading more and more towards the
F6 8" reflector. The physical length of the tube is 110.5cm and will
fit across the back seat of my car, but then again so would the 10" as
it is only 3.3cm longer. However, the 10" is an extra GBP200 which has
pushed it out of my price range (as much as I'd like it).

I had originally been considering the 6" with the short 695mm F5 tube
for portability (which is GBP100 cheaper than the 8") and decided to
check if I was doing the right thing (glad I did). I think I've been
persuaded to spend the little bit extra and get the F6 8" version, even
if it is a bit more cumbersome.

Though the Moon and planets (the most popular beginner's
subjects) are virtually immune to light pollution as long as one can
actually find them in the night sky through the orange fog.

The light pollution I have in Yorkshire is not too bad, though I can get
to a much clearer site in the Dales within a 15 minute drive. However,
I can't wait to get a telescope to my parents house in Northern Ireland
where I grew up (in the countryside with very few populated areas close
by) where the light pollution is virtually non-existent. The naked eye
views of the Milky Way from that site have to be seen to be believed.
They are stunning, even without a telescope. I think that is what got
me interested in astronomy in the first place (plus the Armagh
planetarium which was only a few miles away).

The longer focal length (larger focal ratio) telescope is more
forgiving and allows longer focus eyepieces for the same power
(magnification). Without resorting to yet more expense on a Barlow
lens at the very beginning.

I was considering getting the "standard multi-coated 2x Barlow" (GBP39)
anyway. The eyepieces supplied are a 25mm and 10mm (I believe Plossl)
which should give 48x and 120x magnification. The Barlow should give me
an intermediate (96x) and a higher magnification (240x) which this scope
should be more than capable of if needed. Further down the line I might
get a 6.3mm (~190x) to fill the gap between 120x and 240x. Good idea?

Spectacles might be an issue here.

Luckily not at the moment, but I'm heading that way!!

Regarding the choice of mounting: The EQ5 is said to be far more
solid these days thanks to its new tripod.

The particular EQ5 mount that Orion Optics UK are using is the Synta EQ5
(a.k.a. Antaries). Any opinions on these, good or bad? If they are bad
I could get the optical tube only and a different, better tripod.

But a Dobsonian version is
more easily put to use by the novice who will be confused by the
strange motions of an equatorial mounting at first.

I've ruled out the Dobsonian (even if it is cheaper). Somewhere down
the line I will probably want to attach my digital camera and see what I
can get pictures of. Unfortunately, the camera I have has only got a
maximum exposure of 0.5sec with an equivalent of ISO100. Is this a
problem? Or do I just take a few pictures and stack them (the camera
can be made to automatically take four shots about one second apart)?
OTOH, I have a really old Zenit 35mm camera with a mechanical shutter
which can be left open for as long as I want. If I was to try using
that the Dobsonian would be a no-go.


Andrew

In article , Chris.B
writes

Yes the 10" is a step up in size from the 6" & 8". But there's no
reason why our friend can't get an 8" into his car in the search for
dark skies.

Thanks for the suggestions guys, I'm heading more and more towards the
F6 8" reflector. The physical length of the tube is 110.5cm and will
fit across the back seat of my car, but then again so would the 10" as
it is only 3.3cm longer. However, the 10" is an extra GBP200 which has
pushed it out of my price range (as much as I'd like it).

I had originally been considering the 6" with the short 695mm F5 tube
for portability (which is GBP100 cheaper than the 8") and decided to
check if I was doing the right thing (glad I did). I think I've been
persuaded to spend the little bit extra and get the F6 8" version, even
if it is a bit more cumbersome.

Though the Moon and planets (the most popular beginner's
subjects) are virtually immune to light pollution as long as one can
actually find them in the night sky through the orange fog.

The light pollution I have in Yorkshire is not too bad, though I can get
to a much clearer site in the Dales within a 15 minute drive. However,
I can't wait to get a telescope to my parents house in Northern Ireland
where I grew up (in the countryside with very few populated areas close
by) where the light pollution is virtually non-existent. The naked eye
views of the Milky Way from that site have to be seen to be believed.
They are stunning, even without a telescope. I think that is what got
me interested in astronomy in the first place (plus the Armagh
planetarium which was only a few miles away).

The longer focal length (larger focal ratio) telescope is more
forgiving and allows longer focus eyepieces for the same power
(magnification). Without resorting to yet more expense on a Barlow
lens at the very beginning.

I was considering getting the "standard multi-coated 2x Barlow" (GBP39)
anyway. The eyepieces supplied are a 25mm and 10mm (I believe Plossl)
which should give 48x and 120x magnification. The Barlow should give me
an intermediate (96x) and a higher magnification (240x) which this scope
should be more than capable of if needed. Further down the line I might
get a 6.3mm (~190x) to fill the gap between 120x and 240x. Good idea?

Spectacles might be an issue here.

Luckily not at the moment, but I'm heading that way!!

Regarding the choice of mounting: The EQ5 is said to be far more
solid these days thanks to its new tripod.

The particular EQ5 mount that Orion Optics UK are using is the Synta EQ5
(a.k.a. Antaries). Any opinions on these, good or bad? If they are bad
I could get the optical tube only and a different, better tripod.

But a Dobsonian version is
more easily put to use by the novice who will be confused by the
strange motions of an equatorial mounting at first.

I've ruled out the Dobsonian (even if it is cheaper). Somewhere down
the line I will probably want to attach my digital camera and see what I
can get pictures of. Unfortunately, the camera I have has only got a
maximum exposure of 0.5sec with an equivalent of ISO100. Is this a
problem? Or do I just take a few pictures and stack them (the camera
can be made to automatically take four shots about one second apart)?
OTOH, I have a really old Zenit 35mm camera with a mechanical shutter
which can be left open for as long as I want. If I was to try using
that the Dobsonian would be a no-go.


Andrew

I have used a lot of telescopes in my time, but usually other peoples! However,
I went out and purchased a skywatcher 8" f5 on an HEQ5 mount just a couple of
months ago. The mount is very good, and the optics are at least good, if not
excellent. The OTA was collomited out of the box, which says a lot for the
quality of the mirror cell.

Cost? £575. The 2" 28mm lens is crap, but I have converted it to fit on my
casio 8000SX. Not a bad deal!

Just a thought, really.

Regards,

Geoff GJ