Meade LX90-LNT or Celestron C8-SGT for DSO Astrophotography ?

Hi,

I want to start doing some astrophotography (I am not a complete
beginner to astronomy) - mostly deep-sky objects.
I have a total budget of just over =A32000 - I am now kind of split
between the Meade LX90-LNT (Look North Technology) and a Celestron
C8-SGT (with GoTo technology).

In general I have been told the C8 is a more practical platform (in
terms of portability) and with a decent enough mount for
astrophotography (DSO that is) so I am leaning towards this choice. On
the other hand, the LX90-LNT is probably easier to align correctly for
decent long exposures with a digital camera or CCD, and does seem to
have decent tracking motors.

Does anyone have any views on what platform is better for
astrophotography ? Any other suggestions ?

Thanks and best regards,

--Nuno.

I would be swayed by the fact the LX90 has LNT, it just does the job of
a =A33 compass and =A34 spirit level (and a lot slower).

I've got LX90 (classic I suppose you'd call it now). I'm very happy
with it, it's very easy to use and locates and tracks well.

The mount is solid but you'll need a wedge to do long exposure
photography, you'll maybe stuggle to get it all for =A32000 if you need
to buy EP's and a CCD.

have you considered secondhand? Theres some good deals about now on
Classic LX200's since the GPS model came out, it's something I wish I'd
have considered doing looking back.

All the best

Gaz

Thanks Gaz,

Would you say the LX90 mount and tracking is precise enough for
exposures of say, 10 to 15 minutes ?

Thanks!

--Nuno.

Nuno,

Unguided, that would be about the upper limit I'd guess (mind you I
havn't got around to training my drive yet). I'm currently fitting
mine out to autoguide, you get an LPI camera free with a new LX90 and
you can use this connected to a laptop to 'iron out' any drive errors
buy fixing to a 'guide star' while youre imaging with your main camera.

If you are determined to buy 'new', then =A32000 for a GOTO scope and a
CCD system you are going to have to make consessions somewhere. Most
of of the short commings of the LX90 have 'get arounds' that some times
cost and sometimes don't

I'm sorry I can't help you put the Celestron in some sort of context
but I've never owner one, I looked at buying one when I got my LX90 but
decided against it (but I was only buying for visual use, I did not
intend doing any DSO imaging soi have no idea of their strengths or
weaknesses).

Hope this helps
Gaz

"Gaz" wrote in message
oups.com...
Nuno,

Unguided, that would be about the upper limit I'd guess (mind you I
havn't got around to training my drive yet). I'm currently fitting
mine out to autoguide, you get an LPI camera free with a new LX90 and
you can use this connected to a laptop to 'iron out' any drive errors
buy fixing to a 'guide star' while youre imaging with your main camera.

If you are determined to buy 'new', then £2000 for a GOTO scope and a
CCD system you are going to have to make consessions somewhere. Most
of of the short commings of the LX90 have 'get arounds' that some times
cost and sometimes don't

I'm sorry I can't help you put the Celestron in some sort of context
but I've never owner one, I looked at buying one when I got my LX90 but
decided against it (but I was only buying for visual use, I did not
intend doing any DSO imaging soi have no idea of their strengths or
weaknesses).

Hope this helps
Gaz


My Celestron GoTo ASGT EQ5 mount is nothing but rubbish, the service from
the importer is poor.
Its been back twice now and still its not working. Celestron in the US wash
there hands of you.
Its back again, for the same problem. I have now replaced the Celestron with
a Losmanday.
I have nothing to say thats good anout the mount as you can guess, but this
is just my view.

Steve

The UK SpeedTrap Guide" @ www.ukspeedtraps.co.uk
The UK Weather Guide" @ www.ukstorms.com

Hi

I'm also an LX90 owner, and trying to get my scope into shape as a long
exposure platform. I've seen results from other LX90 users who have
performed long exposure photography. In order to be able to take extremely
long exposure photos, you need to guide the scope, also the scope needs to
be in an equatorial mount.

For the LX90 there are a few toys that you need to be able to guide the
mount. First a guide scope, or some other way of providing a guide image.

The second piece of kit is the Accessory Port Module, this device allows you
to plug in a rectile eyepiece, microfocusser and ccd autoguider. This is
needed for the CCD Autoguider port, this allows you to control the scope
using a Joystick (from BC&F, or homemade) at 2/3 Sidereal rate, so it
doesn't stop the motors and you don't get backlash issues.


Don't believe for a second that any scope will track perfectly without
guiding. The above is specifically for the LX90, but you'll need a similar
type of setup for the C8. Also, the LX90 LNT has Permenant PEC, which will
help to make tracking easier.

Regards

Colin Dawson
www.cjdawson.com


"Nuno" wrote in message
ups.com...
Thanks Gaz,

Would you say the LX90 mount and tracking is precise enough for
exposures of say, 10 to 15 minutes ?

Thanks!

--Nuno.

"Nuno" wrote in message
oups.com...

Hi,

I want to start doing some astrophotography (I am not a complete
beginner to astronomy) - mostly deep-sky objects.
I have a total budget of just over £2000 - I am now kind of split
between the Meade LX90-LNT (Look North Technology) and a Celestron
C8-SGT (with GoTo technology).

In general I have been told the C8 is a more practical platform (in
terms of portability) and with a decent enough mount for
astrophotography (DSO that is) so I am leaning towards this choice. On
the other hand, the LX90-LNT is probably easier to align correctly for
decent long exposures with a digital camera or CCD, and does seem to
have decent tracking motors.

Does anyone have any views on what platform is better for
astrophotography ? Any other suggestions ?
Remember you are going to have to add a good wedge to the LX90, for
astrophotography. You raise the question in another post about exposure
duration. The answer is that it depends on the final resolution of the
system as a whole. Getting much beyond perhaps four minutes, at the focal
length offered by either scope, will be fairly unlikely. Conversely,
piggyback a camera with a 200mm focal length, and you should be able to go
for ages...
The C8, splits into components (mount, OTA, tripod, counterweights),
making it much easier to take 'mobile', than the fork mounted scope, where
the fork, and OTA assembly has to be handled as one piece.
I'd consider going to seperate purchases, and get a HEQ5 mount, which for
the money, has to be one of the best GEMs around. If you want GoTo, rather
than just simple drives, look at the AWR system, which is sold as a
package with the mount, and still only uses just over half your budget
(seriously, the mount is the most important part for astrophotography, so
don't be suprised at this). Then either buy an OTA, or watch the astronomy
advertisements, for one. Either a Celestron, or Meade OTA will be fine
(personally I slightly prefer the Celestron optics, but both are such good
value for money that it is hard to fault them). However also be prepared
to 'reconsider' whether an SCT is the best system for your needs. The SCT,
has the advantage of small size for it's focal length, but has a very
curved focal field. It's big advantage, is that it has a huge backfocus
range, allowing a lot of different accessories to be fitted, but the
quality of even a 'perfect' SCT, degrades if you focus a significant
distance from it's 'design' setup (normally 4" behind the rear port). It's
focal length is rather long for deep sky imaging, but rather short for
planetary work. It is a bit of a 'jack of all trades', and can be bettered
for many uses by other scopes. As an example, for just about your budget,
you could get a new Intes MN86, with mount (but lacking GoTo). This is a
much superior scope (but with a limited backfocus range). Go second hand,
and the options open up even more.

Best Wishes

"Colin Dawson" wrote in message
. uk...

The second piece of kit is the Accessory Port Module, this device allows
you to plug in a rectile eyepiece, microfocusser and ccd autoguider. This
is needed for the CCD Autoguider port, this allows you to control the
scope using a Joystick (from BC&F, or homemade) at 2/3 Sidereal rate, so
it doesn't stop the motors and you don't get backlash issues.

You can do without the accessory port module (APM) if you use a DSI as an
autoguider on a guide scope. The DSI interfaces with a Laptop or PC and can
control the LX90 via the PC and autostar handset interface. I've used this
for 10 minute Autoguided exposures and if it weren't for light polution it
would have been autoguided for longer.

I've heard that guiding via the APM has its advantages but the DSI comes in
pretty cheap. I've tried autoguiding with the LPI but it wasn't sensitive
enough in many cases.

Regards


Chris