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Hi all.

Joined the formum last night after my first use of the Meade LX90 telescope. It was a decently clear night and managed to take a look at the moon but very little else.. Maybe I had massively high hopes of the performance of the telescope but I was very much under awed by the occasion. 

I couldn't afford a new scope so this was delivered used with a single 26mm eyepiece, no erecting prism. Also paid extra for a variable polarising moon filter.

I tried my hardest to align the telescope but failed time and time again due to the fact that the stars selected by the telescope I couldn't really see..

I did a decent amount of research before selecting this telescope and have seen what it can do.. just isn't doing for me at the moment.

So I would love anyone's input as to what I should do next. I assume I need more eyepieces. I get that from reading other threads on this forum.

By the way.. reading the forum really encouraged me to join as you all seem amazingly helpful and so enthusiastic. I remember having a scope as a kid and it just made stars look a little bigger.. Hence I really hoped that this purchase would blow that experience out of the water.. Not yet.. but with your help and input I'm hoping I've made a good scope choice that will give amazing results in the very near future.

I have three young kids and yes I bought the scope for me, but also for them too. I want to be able to point at the nights sky and say.. that star up there is actually Saturn... wanna see it's rings? Then show them using the telescope..

I will stop there.. thanks in advance for any help and advice you may give.

Currently jimmystarblurredgazing.... 

Hipefully with your help and input to become... jimmystargazer..

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When you say your old telescope "made the stars look a little bigger..." - leads me to wonder if you understand how to properly focus a telescope. Stars are properly focused when they appear as the smalled pinpoints of light possible. A telescope won't make stars look bigger - but brighter. Stars are much to far away to magnify regards size.

There's a long thread here you may find quite illuminating <koff!>:

Don't worry - we'll help get you and your telescope works together!

Dave

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Be assured the LX90 is a great scope, you didn't say what scope you have whether its a newer GPS/ACF version or an older classic model but irrespective you should get great views of the night sky.

In terms of alignment the process should be relatively simple and the following is just my process with the LX90 12 I have:

1. Set up the tripod and level it using a surface bubble, I actually use an app on my ipad for this which works well. 2. Mount scope on tripod and lift up the OTA (tube of scope) to the horizontal and level it using a spirit level 3. Using a compass point the front of the telescope towards north. 4. Tighten all the clutches up and switch it on! 5. The telescope will then ask you to perform an alignment and will auto select a couple of stars for you, these typically will be obvious bright stars and when you look along the axis of the tube  you will see what the scope is pointing at. They won't always be in the EP FOV, so don't worry if they are not! Using the finderscope and the handcontroller move the selected star into the center of the FOV of the finder and if your finder is aligned with your scope they should be in your scope FOV. (If not you will need to align your finder with your scope.) Once in the scope FOV, centre the star and press enter. The scope will now slew to the next star and you simply repeat the process, once this is done and all is good the handcontroller will confirm that alignment is successfull and you are good to go.

For future reference I would recommend that you purchase a star chart to familiarise yourself with some of the obvious stars and constellations, this does help with the basic navigation around the sky.

You mentioned that you saw the moon but the views weren't good? I assume you adjusted the focus as much as you can to get the best possible view? If so the moon should have blown your socks off, the detail you can see on the surface of our satellite with a scope like this is quite impressive. If your views were blurred and disappointing then there could be several reasons .1 you put the scope outside and started looking immediately, not good, the optics need to be at thermal equilibrium; therefore these scopes require at least 1.5 hours to cool down outside before use. 2. The eyepiece was fogging up when you put your eye to it, breath etc (this is always an issue on cooler nights and I use a blowerbulb thing to get rid of it 3. Your collimation is off. i.e the secondary is not aligned with the primary, you can easily tell this by de-focussing on a star to see a doughnut shape, if the dark central hole is off centre then collimation is out and your views will be poor. There are tutorials on here / youtube that provides guides on how to fix this.

Hope this Helps.

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Best to align the finder as best as possible prior to using the scope for the alignment with the stars. Then you get the first star in your field-of-view and then dead-center it with the Auto/AudioStar. Now with the tracking of the LX90 engaged - fine-tune your finder. If the stars your handbox chooses aren't visible, you can easily select others. So you're centering the finder, and "training the AutoStar," at the same time.

As my signature reveals, I have a 12" LX90ACF. I had a 12" LX200GPS - but gave it to a professor at my local university who could only afford a 110mm Newtonian Reflector. They pay teachers over here a pittance. I love blowing people's minds! :D

Pay It Foreward,

Dave

 

P.S. - "Training the AutoStar," or whatever it's called now, is made clear in the manual that came with these scopes. If you don't have one - let me know and I'll be happy to link you to one to read~download.

Edited by Dave In Vermont
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Hello Jimmy, and welcome.

Please post a nice clear pic of the kit, and to help us to help you, like this...

FS-102jc.jpg.e26583a263a2b643e582efad4b394a71.jpg

Or, locate the specs label on the telescope itself, and list its information here.

I'm thinking that it's a 150mm or 200mm Schmidt-Cassegrain.  If it is, then Schmidts do require collimating, alignment of the optics inside, especially in that it's used.  That may be part of the problem.  The optics could be fouled as well, and that would result in less-than-stellar images.  "LX90" refers to the mount, not to the telescope primarily, so we'll need some more information.

Cheers.

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Thanks so much for the replies!

 

Feel like I've stepped onto a rather steep learning curve to say the least..

Yes it's a Meade LX90 UHCT Coated lenses. Probably not ACP version as used..

I wanted to invest in a scope that I could learn with, develop and not really need to upgrade.. other than the eye pieces..

Think I need to try to collimate the telescope and hopefully that will improve things immensely.

I need to order the horizontal prism and eye piece holder.. Any suggestions on where to buy?

Cheers all.

Jim

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Here's my LX90 8".. Got a telrad finder on it but no idea what this does?.. look through it and see nothing.. it has red circular circles inside but can't see how that helps me..

Also has a view finder on the left side... Again.. no idea how this is supposed to help me.. best way ive found to align things is just guess work of using my own eyes and aligning as best I can..

I assume there's a logbook earlier way ?

Thanks all for the help, advise and encouragment.

Jim

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Jim,

someone else will be able to advise on the telrad, I've never used one. The other gadget on top of the scope with a wire coming out of it suggests that this scope may well be equipped with meade  LNT (Level North technology)which means the scope will level and find north automatically as part of the alignment process. You will need to consult the manual or google how to use this feature, unfortunately I have no experience of this.

Good luck!

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Hi Jim,

I see you are Bristol based ?

If you can get along to Bristol Astro Society sometime you will be able to get some hands on help. A number of members there have the same or very similar scopes to yours plus the Soceity has a couple as well :smiley:

Here is the website if this is of any interest:

http://www.bristolastrosoc.org.uk/www/

We meet on Fridays and try and have observing sessions on Saturdays, weather permitting, which it often does not !

 

Edited by John
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4 minutes ago, Crose01 said:

Pop a new battery in the Telrad and switch it on low. it works like a gunsight for getting a rough alignment.  

And turn it around perhaps ?

The Telrad finder is mounted backwards in your photo Jim - easy mistake to make though :smiley:

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I am also a very new beginner and am happy to share what I learned so far.  Have you tried taking it outside in the daytime, make sure you are pointing away from the sun and see if you can find a distant object - tree, church, house aerial about 0.5 miles or more away, etc.?  You should be able to focus clearly on a object outdoors - if you can do that the moon should not be problematical.  I found when I first set things up that doing it in the daytime was much easier as I could see what I was doing.  Once you learn how to focus things outdoors you are ready to play with the goto (someone above suggest you have one) and might find it useful to download the app. synscanInit 2 which with the location on you phone turned on should provide all the settings that you might need for the goto unit.

I have also been playing with a red dot finder.  As I understand the Telrad you look through it in a similar way to my one.  You look through and beyond the surface of the finder to the object you wish to find lying behind the screen - a bit like looking through and beyond shotgun aligners to the clay pigeon are shooting at.  Imagine a heads up display with a circle dot on it - if you wanted to look straight at a tree you would need to move your head to align the circle of the heads up display with the tree,  As I understand the Telrad the concentric circles provide a certain concept of distance that can be seen in terms of maybe one or two degrees.  Thus, you get a starting object in the middle and move the telescope so the same object arrives at the edge of one of the circles and this means you have moved the telescope a certain angular distance relative to the sky - thus and following instructions that are published in star guides, you can 'hop' from one object to another using the coloured circles for reference. 

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On 4/2/2017 at 17:04, Jimmystargazer said:

Thanks so much for the replies!

 

Feel like I've stepped onto a rather steep learning curve to say the least..

Yes it's a Meade LX90 UHCT Coated lenses. Probably not ACP version as used..

I wanted to invest in a scope that I could learn with, develop and not really need to upgrade.. other than the eye pieces..

Think I need to try to collimate the telescope and hopefully that will improve things immensely.

I need to order the horizontal prism and eye piece holder.. Any suggestions on where to buy?

Cheers all.

Jim

Ah, a 200mm Schmidt; I thought so.  That looks to be a very nice kit, indeed.

You have several options for a 90° star-diagonal, and for use at night.  During the day, for land targets, there are also 45° Amici-diagonals available.

But we'll need to see an image of your visual-back, there at the rear of the telescope, like this...

visual-back2.jpg.9ec0a217796761809ea00fae8ebca024.jpg

Are you able to insert a diagonal into the v-b, then tighten the screws to hold it; or do you need one that screws onto the v-b, which is common with that type of telescope?

This is an example of one that screws onto the v-b... 

https://www.astronomics.com/images/Product/large/11608.jpg

...and in comparison to the standard type...

58e26c4444484_GSOAmicidiagonal2.jpg.d981dcdc1a0ca8ee1d695004d9de17a5.jpg

Also, when you say "horizontal prism", are you referring to the kind that's used during the day, for corrected, upright images?  If so, that's an Amici, or erect-image, diagonal.

Edited by Alan64
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Another question.. I only have a 26mm eye piece. I assume I need another to view planets? Like a 12.4mm.. would love to view Jupiter and Saturn rings etc.. used the other night and literally saw nothing like I know the telescope is capable of..  if I do need other eye pieces what are your thoughts on a zoom eye piece? 8-30?.. or some thing similar?

Again thank you all for you help and in out.

Jimmy

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15 minutes ago, Jimmystargazer said:

@Alan64 I have a 26mm straight eye piece that I insert and holds in place with a grommet screw. Just need advice on something that lets me view easier, rather than having to get on the floor to look through the eye piece and also turn everything the correct way up.. ?

You need a diagonal to turn the image through 90 degrees. The vast majority of folks using schmidt-cassegrains, refractors and similar scopes use these. A mirror diagonal for astro use will turn the image the right way up but left and right are still reversed. You can get them that will give you a fully corrected image but they use additional glass to do that and we try and minimise the amount of glass that we view astro objects through to keep abberations, light scatter and distortion to a minimum.

Usually folks use 3-4 eyepieces to give a range of magnifications. In the case of the LX90 A 40mm or 32mm is used for the lowest power, then, say a 20mm and a 12.5mm and something like a 9mm for high power viewing (approx focal lengths - something close will do fine !).

The moon should be very sharp when viewed at low to medium magnification. It may get less sharp over 150x - 200x if the seeing conditions are not great.

Yous scope needs 30-40 minutes to cool down if bought from inside. Before that it will be difficult to get clear images of anything because of warm air currents in the tube.

 

 

Edited by John
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30 minutes ago, Jimmystargazer said:

@Alan64 I have a 26mm straight eye piece that I insert and holds in place with a grommet screw. Just need advice on something that lets me view easier, rather than having to get on the floor to look through the eye piece and also turn everything the correct way up.. ?

Very good; then what you need, for use at night, is a 90° STAR  diagonal.  You can choose either a prism-type or a mirror-type.  A quality prism-type is more costly.  

Synta of China equips their current line-up of Schmidt-Cassegrains with this inexpensive prism star-diagonal...

http://www.rothervalleyoptics.co.uk/celestron-90-degree-star-diagonal-125.html

I have one, and it's quite good, especially for the low price...

94115-Ai.jpg.6472fa3ba7556867ce059c76a6d513dd.jpg

I've used that diagonal with a Celestron C90 90mm Maksutov, which is similar in design to your Schmidt-Cassegrain, and I'm pleased with the views; no complaints here.  

Others have had less-than-stellar experiences with it, and I attribute that to the lack of quality-control at the factory there in China. Alternatively, and unfortunately, the next step up in a prism is bit more costly...

http://www.rothervalleyoptics.co.uk/baader-prism-diagonal-t-2-90-degree-32mm.html

That's just the prism and body, which requires an eyepiece-holder and nosepiece to complete it...

http://www.rothervalleyoptics.co.uk/baader-125-helical-focusing-eyepiece-holder-t2.html

http://www.rothervalleyoptics.co.uk/baader-nosepiece-125-t2.html

You'd never need another, unless you get a fast refractor in future to complement the Schmidt -- for low-power, wide-field, binocular-like views -- in which case you'd want a mirror-type.

In so far as the prism-types available, indeed, in so far as all things man-made, it all depends on the level of quality desired.

The mirror-types are more plentiful due to the ease in their manufacture, and consequently permeate the marketplace...

http://www.rothervalleyoptics.co.uk/altair-astro-125-dielectric-star-diagonal.html

Now, if you'd like to use your telescope during the day, for viewing land targets, birds, or other, you would want either a 45° or 90° AMICI(erect-image) diagonal...

http://www.rothervalleyoptics.co.uk/antares-45-erecting-prism-125.html

http://www.rothervalleyoptics.co.uk/antares-90-erecting-prism-125.html

This is what a 45° Amici looks like(left)...

58e4391b9ebca_diagonalcomparison.jpg.65f83729aef2d453b6dc45bf4a5db781.jpg

The 45° would be comfortable for viewing land targets close to the ground, whilst the 90° would be more comfortable for viewing objects higher up, like a mountain top or the top of a tall tree nearby.

If your visual-back might accommodate, and for use at night...

http://www.rothervalleyoptics.co.uk/altair-2-dielectric-diagonal-99-quartz-push-fit.html

...then to use 2" eyepieces and accessories.

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