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Need some sound advice...

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#1 PKG

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Posted 26 December 2018 - 06:56 PM

Okay folks... I have a Meade 10" GPS LX 200.   Bought it used.  I am having great difficulty getting a clear view, both ground level and stellar.  I have done my utmost to collimate (sp) the beast per many articles I have read on several forums... (Very informative and valuable).  Still I get blurry views and images (when trying to photograph).  I am at a loss... Even to the point of unloading the scope... Ending this year frustrated.  Could use some advise.  Thanks for your input.



#2 ToxMan

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Posted 26 December 2018 - 07:10 PM

Since it is used, I wonder if the corrector plate or secondary mirror were removed at some time in the past to clean the primary mirror before your purchased it. And the person put the corrector plate or secondary mirror back in a mal-rotated position? It might be worth checking. Also, it might be worth having a telescope shop check it.


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#3 bobzeq25

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Posted 26 December 2018 - 07:19 PM

Okay folks... I have a Meade 10" GPS LX 200.   Bought it used.  I am having great difficulty getting a clear view, both ground level and stellar.  I have done my utmost to collimate (sp) the beast per many articles I have read on several forums... (Very informative and valuable).  Still I get blurry views and images (when trying to photograph).  I am at a loss... Even to the point of unloading the scope... Ending this year frustrated.  Could use some advise.  Thanks for your input.

Advise.  Visual is a completely different thing from imaging, and you'll get some good advise here on visual.  I'm strictly imaging.  So...

 

If you're starting out and trying to photograph DSOs you need more mount and a lot less scope.  You're not alone with your frustration, as far as imaging DSOs is concerned.  This is an extremely common experience.

 

"I <this was not me> keep running into people who have tried starting out in imaging with big beautiful instruments with longer focal lengths who have had all kinds of frustration - and sometimes sell the equipment because it just isn't worth it."

 

The ones who switch to something like a good 80mm refractor are often suddenly far happier and enjoying life!"

 

But you'll get more and better advise about imaging on the Beginning and Intermediate Imaging forum.  Beginners is strictly for visual.


Edited by bobzeq25, 26 December 2018 - 07:23 PM.

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#4 mperron

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Posted 26 December 2018 - 07:33 PM

Can you post an image you've taken with the telescope. Also a little more information regarding the camera used any anything else that may be in the imaging train (ie. reducer). This may be helpful in diagnosing the issue.

 

By blurry, do you mean out of focus, stars out of round, image looks hazy, etc.?

 

Thanks,

 

Mike


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#5 Bean614

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Posted 26 December 2018 - 07:38 PM

When you look through the eyepiece at an easy object, like the Moon, what do you see when you turn the Focusing Knob?  And what is the focal length of the eyepiece?



#6 SeattleScott

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Posted 26 December 2018 - 07:41 PM

Best thing would be to find a local club so someone could look at it. Ran into a guy with a similar issue at a star party and was able to help him out. Turns out it was just way out of focus and he just wasn’t turning the focus knob enough times in the right direction. Having someone experienced look at it could make all the difference.

Scott
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#7 kfiscus

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Posted 26 December 2018 - 07:42 PM

I'll be of no help to you other than encouraging you to not dump the gear until you hear from the very knowledgeable people here.  We can end your 2018 on a positive note.


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#8 maadscientist

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Posted 26 December 2018 - 07:59 PM

During the day, set the scope up and point it at a far away terrestrial object using the diagonal. You should be able to focus on it with the coarse focus knob. (it will be flipped left to right). Sometimes a previous owner will run the focus so far out (or in) that it will take many turns to bring it back, hence using a daytime object that you can see. If you can do this and the terrestrial object comes into focus, then it will focus skyward. Try on the moon after that, then minor focus changes as you use different eyepieces.

 

Woops, I just reread your post. If this has failed ground level, make sure you have run the focus all they way till it stops. There are many turns available with an SCT as the course focus knob moves the primary mirror. So if you have looked at an object ground level and run the focuser knob till it stops and all the way back the other way till it stops and still nothing, then I would suggest there is probably an alignment issue. I fixed a friends 8 inch Celestron SCT when the glue holding the secondary failed, and it hung at an angle when pointed skyward. Had to take the secondary housing apart and re-glue the secondary. It would have eventually failed and dropped on the baffle tube/primary mirror. Alternatively, sometimes people can try and collimate the secondary and really get the screws too lose tilting it, and they can't get it re-centered tightening it. I have fixed a handful of SCTs that had that problem. If you have a collimating laser, put it where the eyepiece is and see if the return beam comes back down the baffle tube (it does not have to come directly on top of itself, but it must return down the baffle tube). If it doesn't, then the secondary is tilted severely.


Edited by maadscientist, 26 December 2018 - 08:23 PM.

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#9 PKG

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Posted 26 December 2018 - 09:26 PM

WOW!!! Much to consider... And Thanks... I will check out every suggestion.  Mike, when I focus on the moon, it is still out of focus.

Now I wear reading glasses, and wonder if that would affect the focusing.  I figure it would.  And wonder about the fix for that one.

Also, I am trying to use Neximage 5 for the photos I have taken... I cannot even fix the photos in Lightroom... About to just give it up...



#10 ToxMan

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Posted 26 December 2018 - 10:15 PM

Don't wear your reading glasses while observing! But, you may need them to evaluate images.



#11 bobzeq25

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Posted 26 December 2018 - 10:42 PM

WOW!!! Much to consider... And Thanks... I will check out every suggestion.  Mike, when I focus on the moon, it is still out of focus.

Now I wear reading glasses, and wonder if that would affect the focusing.  I figure it would.  And wonder about the fix for that one.

Also, I am trying to use Neximage 5 for the photos I have taken... I cannot even fix the photos in Lightroom... About to just give it up...

Break this into two pieces.  Visual and imaging.  Your scope is very suitable for visual astronomy, people here can help.

 

Imaging is a completely different matter.  Your scope is not at all well suited for starting out in that.

 

People think the camera is just a better version of your eye.  It's not at all like that.



#12 Ken Sturrock

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Posted 26 December 2018 - 11:22 PM

Moved to Cats & Casses.



#13 WadeH237

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Posted 27 December 2018 - 09:12 AM

Can you post an image that you've taken?  I should be unprocessed, other than stretching to make the stars visible.

 

There's lots of speculation here, but seeing what the scope is producing would help us to understand what's actually going on.


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#14 PowellAstro

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Posted 27 December 2018 - 09:39 AM

What does a star or artificial star look like at 50x per inch? And then again just as you go past best focus? Does the corrector plate have a deep blue/purple hue when you look into the front of the scope? If not it may have been replaced with plate glass and could be the main issue. Can you post a picture of the scope from the front?

#15 rmollise

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Posted 27 December 2018 - 10:17 AM

Okay folks... I have a Meade 10" GPS LX 200.   Bought it used.  I am having great difficulty getting a clear view, both ground level and stellar.  I have done my utmost to collimate (sp) the beast per many articles I have read on several forums... (Very informative and valuable).  Still I get blurry views and images (when trying to photograph).  I am at a loss... Even to the point of unloading the scope... Ending this year frustrated.  Could use some advise.  Thanks for your input.

 

Well, let's see.

 

A 10-inch SCT will rarely produce acceptable terrestrial views/images. There's a lot of focal length and temperature effects off the ground ensure "blurry."

 

The sky? Do you let the telescope acclimate for a sufficient length of time outdoors before attempting to use it? This time of the year, that is often at least an hour.

 

Either your collimation is in or it isn't. If you aren't sure, enlist the aid of a local amateur astronomer experienced with these telescopes (try your local astronomy club).

 

For new users, a telescope like a 10-inch computerized SCT is often a source of frustration. A smaller SCT or refractor might be far more useful for you. smile.gif

 

Otherwise? There's unlikely to be anything wrong with the telescope (unless you've misadjusted the collimation). The corrector or something is VERY unlikely to be the source of your problems, so don't go disassembling the scope as one poster seemed to be hinting. ;)


Edited by rmollise, 27 December 2018 - 10:20 AM.

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#16 RAKing

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Posted 27 December 2018 - 10:52 AM

Well, let's see.

 

A 10-inch SCT will rarely produce acceptable terrestrial views/images. There's a lot of focal length and temperature effects off the ground ensure "blurry."

 

The sky? Do you let the telescope acclimate for a sufficient length of time outdoors before attempting to use it? This time of the year, that is often at least an hour.

 

Either your collimation is in or it isn't. If you aren't sure, enlist the aid of a local amateur astronomer experienced with these telescopes (try your local astronomy club).

 

For new users, a telescope like a 10-inch computerized SCT is often a source of frustration. A smaller SCT or refractor might be far more useful for you. smile.gif

 

Otherwise? There's unlikely to be anything wrong with the telescope (unless you've misadjusted the collimation). The corrector or something is VERY unlikely to be the source of your problems, so don't go disassembling the scope as one poster seemed to be hinting. wink.gif

I agree with what Rod is saying and just want to add some more advice and encouragement.

 

Number one - imaging is almost a separate hobby from observing and it requires a longer learning time.  Leave the camera indoors for now.

 

Based on your messages, you know how to get the scope set up and running.  So just go observe something.  Set the scope outside long enough (0ne hour or more) to get acclimated.

 

Pull off your reading glasses to observe.  Yes, I have to use readers to see the hand paddle and navigate around, so any observing session is going to be an "on, off, on, off, ad nauseum" with the glasses.  It's the cost of growing old! tongue2.gif   I have never tried to focus an SCT with my readers on, so I don't even know if it's possible.  You are trying to focus on infinity, so use the plain eyeball or the glasses you need for driving.

 

Please don't mess with the collimation until you can focus on something with your eyes.

 

Cheers,

 

Ron



#17 treadmarks

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Posted 27 December 2018 - 01:05 PM

Can you post an image that you've taken?  I should be unprocessed, other than stretching to make the stars visible.

 

There's lots of speculation here, but seeing what the scope is producing would help us to understand what's actually going on.

Second this. There are people on these forums who are very good at reading star tests. Since you're set up for photography, maybe you could supply one. You just point it at a very bright star and defocus until you see rings instead of a star.



#18 Bean614

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Posted 27 December 2018 - 09:16 PM

And I will ask again---- when using it visually, on the Moon, what is the Focal Length of the Eyepiece you are using?  32mm, 26mm, 13mm, etc.???



#19 WadeH237

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Posted 28 December 2018 - 11:23 AM

Pull off your reading glasses to observe.  Yes, I have to use readers to see the hand paddle and navigate around, so any observing session is going to be an "on, off, on, off, ad nauseum" with the glasses.  It's the cost of growing old! tongue2.gif   I have never tried to focus an SCT with my readers on, so I don't even know if it's possible.  You are trying to focus on infinity, so use the plain eyeball or the glasses you need for driving.

This has been mentioned a couple of times.

 

You can certainly observe with your readers.  You just need to tweak focus a bit to accommodate.  And it might actually be *best* to observe with them, depending on whether you normally wear glasses.

 

I've been nearsighted all my life and worn glasses.  As I've gotten older, I've lost my very near vision, so I wear progressive bifocals.  These daily wear glasses are not very good at all for astronomy.  When I look at the sky naked eye, the progressive bifocals have a fairly small "sweet spot" where the stars are sharp.  In other areas of my field of vision, the stars are either distorted or out of focus.  If I am wearing these glasses when I look through the eyepiece, my focus might vary, depending on whether I get my eye and glasses in the exact same spot each time.

 

To solve this problem, I often use my readers.  They have the same power through most of my field of view, and they also correct for a slight astigmatism.  With the readers, I can see a sky chart or look through the eyepiece and see everything fine.  I just don't see the night sky naked eye with the readers.

 

I also have a pair of glasses that are just for distance vision, they show me the entire sky clearly when I look naked eye.  And when I focus the telescope with them, it's close to the right focus for someone else if they have 20/20 vision.  But I can't see sky charts at all with them, so I generally only use them for the eyepiece when I am doing outreach.  Otherwise, I use the readers.



#20 PKG

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Posted 29 December 2018 - 07:29 PM

You folks are great.. I've been checking out the scope and noticed that the secondary mirror is not in centered on the corrector plate.  I am debating whether or not to fix that.
I did clean the primary mirror and corrector plate and it made a noticeable difference.  But not good enough in my humble opinion.
Collimation seems to be still really off. 
My question:  Does the centering of the secondary mirror on the corrector plate make that much difference?  



#21 PowellAstro

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Posted 29 December 2018 - 07:58 PM

Absolutely, more so for the Meade coma free and most Celestrons. The older Meade SCs are more forgiving. But I would try to get it within a few mm of dead center.
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#22 PowellAstro

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Posted 29 December 2018 - 08:02 PM

You will need very steady air to truly Collimate the 10. I would try an artificial star inside first and get it dialed in. You will still, most likely need to tweak it under the stars but it will be real close.
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#23 maadscientist

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Posted 03 January 2019 - 01:12 PM

You folks are great.. I've been checking out the scope and noticed that the secondary mirror is not in centered on the corrector plate.  I am debating whether or not to fix that.
I did clean the primary mirror and corrector plate and it made a noticeable difference.  But not good enough in my humble opinion.
Collimation seems to be still really off. 
My question:  Does the centering of the secondary mirror on the corrector plate make that much difference?  

Take a measuring tape and measure from the edge of the secondary to the edge of the scope. Do this as you go around the scope and write doen the measurements. You need to do it at at least 4 positions, 12 o'clock, 3 o'clock, 6 o'clock, 9 o'clock. If the measurements are the same (or within 1/16 or 1/8 th inch or so), then the physical position of the secondary is fine. If not, then the secondary must be re-centered). Then point the scope parallel to the ground and look in it from about 6 feet away straight on (make sure you are centered). You should see the secondary as not centered in the reflection, meaning that collimation is way off. If this is the case, you can attempt to bring the gross collimation error under control by adjusting the secondary until the reflection line up, but you will have to finish on a star at night. Alternatively, or to finish more precise collimation, you can set the scope up and point at Polaris. If you cannot get the goto to work, you can manually put the scope on Polaris, it will be in the field of view enough to collimate. Make small manual adjustments and recenter Polaris (either with hand paddle or manually) each time to check.


Edited by maadscientist, 03 January 2019 - 01:20 PM.

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#24 photoracer18

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Posted 03 January 2019 - 04:45 PM

Okay folks... I have a Meade 10" GPS LX 200.   Bought it used.  I am having great difficulty getting a clear view, both ground level and stellar.  I have done my utmost to collimate (sp) the beast per many articles I have read on several forums... (Very informative and valuable).  Still I get blurry views and images (when trying to photograph).  I am at a loss... Even to the point of unloading the scope... Ending this year frustrated.  Could use some advise.  Thanks for your input.

I could do the collimation for you if you want, and help you test it. I used to work doing repairs and such at Hands On Optics. Still have my Hotech holographic laser. Are sure the issue is collimation? I will be in Frederick on both 1/5 and 1/6 and will be free by about 1:30 PM both days. Send me a PM if you want to get together.

While the basic SCT design is more forgiving on secondary centering than say a Mak that does not mean that you should not fool with it if the amount is noticeable by eye.


Edited by photoracer18, 03 January 2019 - 04:47 PM.


#25 PKG

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Posted 07 January 2019 - 04:06 PM

Update...  Collimated the scope... One screw extremely tight, the other very loose... Disassembled the secondary mirror assembly and found that one of the springs was completely flattened and 'ruined'.  One was out of sorts, and the third, seemingly fine. Contacted Meade to order new springs... In the mean time, I just re-stretched the springs, realizing that that wont help much.

Have come to the conclusion that the previous owner may have had some issues.  I am pretty 'hellbent' on getting the scope in shape.  Of course, there is always an out... A new OTA...

Once again, thank you all for your help.  I am still trying to figure out how to 're-align' the optics... If possible...




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