Jump to content

  •  

CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.

Photo

Four leaf clover shaped stars with refractor

  • Please log in to reply
11 replies to this topic

#1 unimatrix0

unimatrix0

    Viking 1

  • -----
  • topic starter
  • Posts: 802
  • Joined: 03 Jan 2021

Posted 28 June 2021 - 11:16 AM

I know I'm starting another thread, but I got multiple issues I'm trying to tackle. 

I have the W.O. Z61 doublet and this issue been around since I purchased it last year November. 
I am just not experienced and was even less experienced 6 months ago so I didn't think this was an issue

The closest thing I can compare the shape the stars upon zooming in is a 4-leaf clover shape. 

Like the star is divided into 4 pieces . I know it's not out of focus, because the Bathinov mask shows excellent focus. 

Is it out of collimation?  It has tiny plastic screws under the dew shield, no indication of what they do. 

 

I know I've been having some issues getting a flat field before I even looked at this, and that's  with the dedicated flattener attached. 

One side of the image always look like the stars are egg shaped, while the other and the center looks better. 

 



#2 Deesk06

Deesk06

    Viking 1

  • *****
  • Posts: 824
  • Joined: 25 Jul 2015
  • Loc: New Jersey

Posted 28 June 2021 - 11:24 AM

Do you have an image we could look at?



#3 unimatrix0

unimatrix0

    Viking 1

  • -----
  • topic starter
  • Posts: 802
  • Joined: 03 Jan 2021

Posted 28 June 2021 - 12:31 PM

Do you have an image we could look at?

Not yet, but tonight I'm gonna put the telescope on a fixed tripod and try to recreate what I saw last night and take a snapshot of Polaris.
Once I saw the weird thing with the star, I removed the scope and used the other instead, because I didn't waste the clear night. 


Edited by unimatrix0, 28 June 2021 - 12:33 PM.


#4 ChrisWhite

ChrisWhite

    Fly Me to the Moon

  • *****
  • Posts: 7,073
  • Joined: 28 Feb 2015
  • Loc: Northeast USA

Posted 28 June 2021 - 12:42 PM

Is this the iron cross shaped stars that WO can be famous for?
  • unimatrix0 likes this

#5 Jim Waters

Jim Waters

    Fly Me to the Moon

  • *****
  • Posts: 6,164
  • Joined: 21 Oct 2007
  • Loc: Phoenix, AZ USA

Posted 28 June 2021 - 01:32 PM

Pinched optics?



#6 unimatrix0

unimatrix0

    Viking 1

  • -----
  • topic starter
  • Posts: 802
  • Joined: 03 Jan 2021

Posted 28 June 2021 - 09:29 PM

Here is some images I just took of Polaris from a fixed mount.  I checked it with Bathinov, it's in focus.  Ok so no 4 leaf clover, more like German Iron Cross medal lol! 

 

Then I took it out of focus on purpose to see collimation.  What's going on here? 
 

 

bath.png
clover.png
outof.png


Edited by unimatrix0, 28 June 2021 - 09:30 PM.


#7 ChrisWhite

ChrisWhite

    Fly Me to the Moon

  • *****
  • Posts: 7,073
  • Joined: 28 Feb 2015
  • Loc: Northeast USA

Posted 28 June 2021 - 09:42 PM

Do a search for William Optics Iron cross problem. I can't recall the fix but I think there are some screws to adjust. An aperture mask would help as well, but if you can it would be ideal to fix without slowing down your scope.
  • unimatrix0 likes this

#8 unimatrix0

unimatrix0

    Viking 1

  • -----
  • topic starter
  • Posts: 802
  • Joined: 03 Jan 2021

Posted 28 June 2021 - 09:48 PM

Do a search for William Optics Iron cross problem. I can't recall the fix but I think there are some screws to adjust. An aperture mask would help as well, but if you can it would be ideal to fix without slowing down your scope.

 

I took the dew shield off, and the lens are held in with plastic worm screws with a flat head screw driver needed.  4x2 around the lens. So 4 spots diagonally from each other 2 screw each spot.

These plastic screws are very finicky, easy to ruin them with a flat head screw driver.

I didn't have it this bad during winter, but I guess with the summer heat, they must have tightened as the glass expanded? 

I'm also reading into this thread: 
https://www.cloudyni...sue-fix-thread/



#9 unimatrix0

unimatrix0

    Viking 1

  • -----
  • topic starter
  • Posts: 802
  • Joined: 03 Jan 2021

Posted 28 June 2021 - 09:54 PM

Ok, so I'm gonna do this. These guys in that thread had an issue when it was getting colder. I am in the reverse effect here. It got  a lot warmer , so I'm guessing I'm gonne loosen the plastic screws that hold the outer lens , 

https://www.cloudyni...read/?p=6494121



#10 unimatrix0

unimatrix0

    Viking 1

  • -----
  • topic starter
  • Posts: 802
  • Joined: 03 Jan 2021

Posted 29 June 2021 - 02:13 PM

Long story short, I loosened all those little plastic screws. 
I also decided to test it, so what's better than using a barely functioning Skywatcher AZ GTI mount and a camera with tiny sensors to test a telescope with bad diffraction? lol.gif

 

So I did this, it was almost 2am last night, I quickly did a polar alignment, the AZ GTI has a huge backlash though so I had to delete about 40 subs. 

No guiding.  My main rig is on a long term assignment imaging something else for 4 days now. 

 

This one is made of 142x 40 second subs with the W.O Zenithstar 61 (after adjustment on the lens screws) and QHY 183C at gain 8 + Skywatcher AZGTi with wedge + N.I.N.A + DSS+ Photoshop. 

No filters.  Just stacked it with DSS and did some beauty salon treatment in Photoshop
 

Photometric-CCBackground-extraction-Corr


Edited by unimatrix0, 29 June 2021 - 02:23 PM.


#11 Mike in Rancho

Mike in Rancho

    Apollo

  • -----
  • Posts: 1,393
  • Joined: 15 Oct 2020
  • Loc: Alta Loma, CA

Posted 29 June 2021 - 03:33 PM

Did you fix it?  I can't tell.

 

When I was chasing funny-looking stars (no screws for me, turned out to be an aperture circumference issue) I just aimed at something very bright - Sirius, Rigel, Capella.  Doesn't even take a whole lot of exposure, those will reveal flaws in the stars quite readily.



#12 unimatrix0

unimatrix0

    Viking 1

  • -----
  • topic starter
  • Posts: 802
  • Joined: 03 Jan 2021

Posted 29 June 2021 - 06:17 PM

Did you fix it?  I can't tell.

 

When I was chasing funny-looking stars (no screws for me, turned out to be an aperture circumference issue) I just aimed at something very bright - Sirius, Rigel, Capella.  Doesn't even take a whole lot of exposure, those will reveal flaws in the stars quite readily.

Neither can I lol. It's better I guess, but the star shapes I saw on first try still weren't totally round. 




CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.


Recent Topics






Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics