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Miss-shapen stars ES127 FCD100 CF

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#1 rdmarco

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Posted 09 May 2020 - 02:45 PM

I have a new ES127 FCD100 CF refactor. I image with a DSLR (canon 800D). I have been having a problem with oddly shaped stars. I use a Bahtinov mask. What causes this? Focus? collimation error? I have attached an image of my focus on a star after using the mask.

 

Thanks for any help.

 

Rob

Attached Thumbnails

  • Single__0015_ISO3200_7s__58F.jpg


#2 Jim Waters

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Posted 09 May 2020 - 03:43 PM

I don't know the design of the lens cell but it could be pinched optics?  What other optics, filters, diagonals ...etc are connected to the scope?

 

Is the scope under warranty?  



#3 kevindt

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Posted 09 May 2020 - 04:24 PM

With as few visible stars and as low a magnification of the image it's hard to tell.  I wonder if it is camera/focuser tilt, but I can't see enough stars at the top and bottom of that jpeg to really tell. 

 

My non-CF version of this same scope had a lot of lateral play in the focuser and in the rotation ring when it arrived, and non-circular stars.  After carefully taking up the play in the focuser and centering it, and by using the two provided extension rings so that the focuser draw-tube was almost fully inside the focuser at focus, the stars became nicely round and the whole setup became much more rigid, even with a flattener, filter wheel and cooled camera on the back end..


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#4 droe

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Posted 09 May 2020 - 04:24 PM

I have the same scope and I do not see that in mine.

 

If you connect the camera or better yet a different camera directly to the scope with no reducer/flattener/diagonal/filters or any other thing you could connect and you still get that shape I would send it back. 


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#5 Jim Waters

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Posted 09 May 2020 - 04:33 PM

Rotate the camera ~90 degrees.  Does the star pattern change / move with the rotation?


Edited by Jim Waters, 09 May 2020 - 04:34 PM.


#6 rdmarco

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Posted 09 May 2020 - 06:01 PM

I have the same scope and I do not see that in mine.

 

If you connect the camera or better yet a different camera directly to the scope with no reducer/flattener/diagonal/filters or any other thing you could connect and you still get that shape I would send it back. 

No flattener. Just an L-Pro filter.



#7 rdmarco

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Posted 09 May 2020 - 06:01 PM

Rotate the camera ~90 degrees.  Does the star pattern change / move with the rotation?

I'll give that a try. Thanks.



#8 rdmarco

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Posted 09 May 2020 - 06:05 PM

With as few visible stars and as low a magnification of the image it's hard to tell.  I wonder if it is camera/focuser tilt, but I can't see enough stars at the top and bottom of that jpeg to really tell. 

 

My non-CF version of this same scope had a lot of lateral play in the focuser and in the rotation ring when it arrived, and non-circular stars.  After carefully taking up the play in the focuser and centering it, and by using the two provided extension rings so that the focuser draw-tube was almost fully inside the focuser at focus, the stars became nicely round and the whole setup became much more rigid, even with a flattener, filter wheel and cooled camera on the back end..

I am using the two supplied extension tubes with no flattener. This is really annoying. Nice scope otherwise. And Yes, the scope is under warranty. Bought it from OPT just a couple of weeks ago.


Edited by rdmarco, 09 May 2020 - 06:06 PM.


#9 Jim Waters

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Posted 09 May 2020 - 06:22 PM

Image without the L-Pro filter too.  If the star images are still problematic return the scope.



#10 Hondo

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Posted 09 May 2020 - 06:33 PM

It may or may not be of help but have a look at this thread, post #8 in particular.

 

https://www.cloudyni...s-ed127-fcd100/



#11 Jim Waters

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Posted 09 May 2020 - 06:41 PM

I really don't think there's anything like - "shipping screws for the lens cell were not removed"...  That pattern in the other post is a classic sign of over tight collimation screws. 

 

Call OPT Tech Support and talk to them.

 

EDIT - Ask for another scope.


Edited by Jim Waters, 09 May 2020 - 06:56 PM.


#12 stevew

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Posted 09 May 2020 - 06:45 PM

Is it just me, or are there a lot of post like this by ES refractor owners?

It seems there is a post every week about this same subject.


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#13 Jim Waters

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Posted 09 May 2020 - 06:55 PM

Is it just me, or are there a lot of post like this by ES refractor owners?

It seems there is a post every week about this same subject.

Yes - you are right.  Too many posts with issues.  I don't know how their lens test but their QC is lacking...!



#14 rdmarco

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Posted 09 May 2020 - 07:15 PM

I really don't think there's anything like - "shipping screws for the lens cell were not removed"...  That pattern in the other post is a classic sign of over tight collimation screws. 

 

Call OPT Tech Support and talk to them.

 

EDIT - Ask for another scope.

I'll be calling tomorrow AM.



#15 Jim Waters

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Posted 09 May 2020 - 07:48 PM

Test the scope before you talk to them.  No filters, FF, FF/FR or anything else.  Reproduce the above image on a bright star.  If you still get the spike call OPT and ask for Tech Support.  Insist on a replacement scope.  They will likely push back.  Be firm and insist on a new scope...

 

If the spike went away add the L-Pro filter and retest.  If the spike returns make sure the filter is clean.  If the filter looks clean get a replacement filter.

 

Get back to us with an update.



#16 rdmarco

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Posted 09 May 2020 - 08:36 PM

Test the scope before you talk to them.  No filters, FF, FF/FR or anything else.  Reproduce the above image on a bright star.  If you still get the spike call OPT and ask for Tech Support.  Insist on a replacement scope.  They will likely push back.  Be firm and insist on a new scope...

 

If the spike went away add the L-Pro filter and retest.  If the spike returns make sure the filter is clean.  If the filter looks clean get a replacement filter.

 

Get back to us with an update.

Will do. Thanks.



#17 rdmarco

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Posted 11 May 2020 - 09:43 AM

Well, did the test on a star last night without the L-Pro filter. Same problem. Talked to OPT. Asked for a replacement. They are pawning it off on Explore Scientific. What a bummer for such an expensive scope.

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  • OpticsWithoutFilter.jpg

Edited by rdmarco, 11 May 2020 - 09:44 AM.


#18 droe

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Posted 11 May 2020 - 10:32 AM

I would think OPT would help you out but I have not used them.

 

ES has great customer service and I hope they can help you out. It is really an excellent telescope (when it is working).



#19 Jim Waters

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Posted 11 May 2020 - 12:36 PM

OPT has or did have a 30 day replacement policy.  I am sorry you have to go through this Rob.



#20 rdmarco

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Posted 11 May 2020 - 05:41 PM

OPT has or did have a 30 day replacement policy.  I am sorry you have to go through this Rob.

Thanks! At least I can return it. They say I must pay for shipping, though. There goes galaxy season. Oh well.



#21 rdmarco

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Posted 11 May 2020 - 06:22 PM

Well, the stories about Explore Scientific's customer support are true. They called and are shipping a replacement tomorrow! They suspect the tight screws from shipping issue. 

 

I may have some galaxy season left yet! Hurrah for ES customer support.

 

Rob


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#22 daquad

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Posted 11 May 2020 - 06:26 PM

I had an ES 127 triplet.  Same problem.  Severe astigmatism visible even at low power.  Sent it back.  Haven't considered buying an ES scope since.

 

Dom Q.



#23 rdmarco

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Posted 12 May 2020 - 11:22 AM

I had an ES 127 triplet.  Same problem.  Severe astigmatism visible even at low power.  Sent it back.  Haven't considered buying an ES scope since.

 

Dom Q.

But yet so many have had great success with them. They come highly recommended by more than a few. There must be more to the story here. I'll followup when I get the replacement.


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#24 droe

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Posted 12 May 2020 - 11:35 AM

First look at the Moon in that scope and you will know you made the right choice.



#25 Eddgie

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Posted 12 May 2020 - 11:58 AM

It looks like some kind of diffraction artifact to me.  Try defocusing about 5mm on a field of bright stars or four images with the bright defocused star near each comer.

 

If you want me to look at it, PM the picture to me.  I often don't return to posts once I respond because I just don't always remember too.

 

It looks like a diffraction artifact though. 


Edited by Eddgie, 12 May 2020 - 11:59 AM.



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