AutoGuiding an LX90

Hi all.

Some of you may be aware that I'm keen on Astrophotography, I do like being
able combine the best bits of old school and new school techniques, cherry
picking on the best parts of both worlds in order to get the most pleasent
and enjoyable experience from the hobby. I've been playing about with a
webcam for short exposure planetary and lunar stuff, with a little success.
However, my main objected is real deep sky work.

From this winters photo season, (each year I try to demonstrate why a piece
of kit is needed) I've captured a good photo of the Great Orion Nebula.
However, the image proves, the need for guiding the scope, and the need for
Periodic Error Correction. I'm thinking about sending the photo into
Astronomy now, as it does provide a really good demonstration of the
problems that we have to overcome, you can even see the Nebula in the photo.

Anyway, from this I've decided that I should really be thinking about
getting an Autoguiding solution in time for next winters season. I do have
a laptop, with lots of USB ports available, so connecting a camera isn't
going to be a problem. My scope is the Meade LX-90, so I know that I can
get the APM for it, which has connections for an Autoguider. Apart from
this, I know nothing about what's needed to get something up and running.

Regards

Colin Dawson
www.cjdawson.com

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

I should really be thinking about getting an Autoguiding solution in time
for next winters season.
Apart from this, I know nothing about what's needed to get something up
and running.

Hi Colin

With my limited knowledge I'd hoped that someone else would answer you....

For what its worth:-
I'm aware of a couple of methods but haven't tried any of them yet owing to
the limited opportunity and keeness to play with the DSI when the sky is
clear. Also myself, rather than the telescope tracking is the limiting
factor. I'll probably get into playing with the guiding functions when I get
another DSI and learn how to accurately polar align (maybe something you can
help me with?). I've even got astro-engineering's 'polarmate' and still
can't get it right. Must be a consequence of growing up without a pole star
;-)

You'll need a guidescope piggybacked onto your LX90. I bought a cheap-ish
80mm Skywatcher Refractor OTA for £119 from
http://www.warehouseexpress.co.uk/ . The telescope itself has been used more
for its F/5 optics in imaging rather than the guiding. I'm presently
surprised with this aspect of this additional use. Following the additional
weight of the OTA, you'll be buying a few counterweights for the LX90 OTA
(how one requirement always leads to another...)

The piggyback mountings don't come cheap, you may want to consider a DIY
solution. I've seen a few homemade solution's on the 'net that'd do but
ended up buying a solution from telescope house that's made by
astro-engineering http://www.astro-engineering.com/ . They sell two types,
The OTA I'd bought forced me into the parallel rail ring mounting system
which I sold a kidney to fund.

Once the optics are in place and aligned you can use a webcam with
'guidedog' software http://www.barkosoftware.com/GuideDog/ .

An issue with the webcam idea is exposure time, sensitivity and potential
for guiding without a bright object in visible the FOV. Some are starting to
the use the Meade DSI as an autoguider. This comes in at about £270 if
bought in the UK but does have the added bonus of having autoguiding built
into its software as an addition to the imaging functions. Also being a
Meade product which integrates just nicely with your telescope.

Hope this helps

Best Regards


Chris

Hi Chris.

I get the inpression that Autoguiding is something that's not for the faint
hearted. Thanks for the information, I was beginning to think along
similar lines. I've been doing a little digging about, and have taken a
close look at the Off-Axis guider, but it seems from what's been said that
these are not really as useful as they first appear, besides, I'd prefer to
have the main scope concentrating on the image.

The guide speed joystick looks good, but there's no way I'm paying £90 for
one, looks like a simple little project to make. Shame that I don't still
have an old joystick from a ZX Spectrum, it would work perfectly in this
situation. A project box with a few microswitches will suffice and will be
cheap enough to make. That will solve the adjustment part of the problem.
Using a skywatcher OTA as a guide scope does make alot of sense. The only
other must have piece of kit would be the balance weight set. In fact I
might get that next. This will, of course set me up nicely with a manual
guiding solution. I've been doing a little research, and think that to
auto guide properly I'll need a more powerful camera which will cost yet
another small fortune.

I'll work on a document explaining how I align my scope. It's a pretty
simple routine, but it does work well. It not perfect, as it's a simple
polar alignment. I could do with learning how drift align to iron out the
last wrinkle. In a nutshell accuracy is the name of the game for
performing a proper and useful polar alignment.

Regards

Colin Dawson
www.cjdawson.com


"Chris Taylor" wrote in message
...

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

I should really be thinking about getting an Autoguiding solution in time
for next winters season.
Apart from this, I know nothing about what's needed to get something up
and running.

Hi Colin

With my limited knowledge I'd hoped that someone else would answer you....

For what its worth:-
I'm aware of a couple of methods but haven't tried any of them yet owing
to the limited opportunity and keeness to play with the DSI when the sky
is clear. Also myself, rather than the telescope tracking is the limiting
factor. I'll probably get into playing with the guiding functions when I
get another DSI and learn how to accurately polar align (maybe something
you can help me with?). I've even got astro-engineering's 'polarmate' and
still can't get it right. Must be a consequence of growing up without a
pole star ;-)

You'll need a guidescope piggybacked onto your LX90. I bought a cheap-ish
80mm Skywatcher Refractor OTA for £119 from
http://www.warehouseexpress.co.uk/ . The telescope itself has been used
more for its F/5 optics in imaging rather than the guiding. I'm presently
surprised with this aspect of this additional use. Following the
additional weight of the OTA, you'll be buying a few counterweights for
the LX90 OTA (how one requirement always leads to another...)

The piggyback mountings don't come cheap, you may want to consider a DIY
solution. I've seen a few homemade solution's on the 'net that'd do but
ended up buying a solution from telescope house that's made by
astro-engineering http://www.astro-engineering.com/ . They sell two types,
The OTA I'd bought forced me into the parallel rail ring mounting system
which I sold a kidney to fund.

Once the optics are in place and aligned you can use a webcam with
'guidedog' software http://www.barkosoftware.com/GuideDog/ .

An issue with the webcam idea is exposure time, sensitivity and potential
for guiding without a bright object in visible the FOV. Some are starting
to the use the Meade DSI as an autoguider. This comes in at about £270 if
bought in the UK but does have the added bonus of having autoguiding built
into its software as an addition to the imaging functions. Also being a
Meade product which integrates just nicely with your telescope.

Hope this helps

Best Regards


Chris