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Posted (edited)
On 01/04/2019 at 10:04, RolandKol said:

The problem is actually in all those tutorials...

I fell on them, probably just like majority newbies did... I do believe my PDS was quite well collimated, but it was my first scope for AP, and I read a lot and checked youtube tutorials before I touched the secondary, and guess what?

All of the tutorials suggest to adjust the secondary during the usual collimation routine of the primary, and guess what? None of them actually highlight, - "Do not touch the Central Bolt of the secondary!!!".

So I have adjusted even the central bolt as other 3 were quite tight...

And later star test became soo bad... Just like yours... And maybe even worse! And I had only laser at that time and could not figure out why it is so bad, as laser beam was in center and etc ;)

So I ordered Cheshire, while waiting it to come by post, disassembled scope into small peaces, flocked it, centered focuser, placed Autofocuser, put all back together and had a prolonged battle with the secondary... Which is not yet 100% finished :)

P.S. But I would afraid to do it to Quattro!!! :) 130PDS is in completely different price range... in fact, thats why I bought it, - to learn the "anatomy" of the Newtonian

plus, I guess... Battle with F4 is much more difficult than with F5

Battle with F5 is the same as F4 :) .some screws are ill fitting and kind of small , thats all .

 

Internet offers wisdom of lightnig speed, can make even Plumbers rocket scientist with few clicks. God,dont mean to under rate a plumbers intelligence.

Some r bible long and totally sense twisted these articles. Create a sense of scariness to touch  the secondary or the scope itself.

To be honest there s nothing so really very complicated with this mirror and few Chinese  screws . Kind of exaggerated this  dont touch it propoganda.

Most of them are crude made and kind of simple.  This F4 mirror is glued with  double side  adhesive tape for carpets and home appliances i guess.

While washing mirror i was cautious not to wet it.  Using dew straps around and overheating can make loose the adhesive tape  (who knows)

Primary too needs cleaning, so after mastering offset secondary lesson move on to the next mystic myth:)

Meantime  waiting for the Cheshire CT, with collimation cap got the secondary round as possible.

Barlowed (2XBarlow) the laser and adjusted the secondary doughnut on the laser window screen. This is where im now,

View through the d.tube

IMG_0941.jpg.bfe1ca560d3615f2d398eb6ef2b12cec.jpg

Barlowed laser and secondary doughnut on the laser window.

IMG_0953.jpg.52702958d1ab7271d228db4de57673ee.jpg

Test shot on NGC 3187 and co inspired by Mr Alacante :)

L3187.jpg.d2b05a484b4f7abe28be24a51df2ded5.jpg

Ordered one TS Concenter along with Cheshire CT. lets see what a Concenter ( magic tool ) does.

Sorry , if i wrote too much. Thanx 4 reading:)

CS

 

Edited by Rush
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A lot of people get over anxious with collimation 

Unless you are transporting your Dob, like I do, out couple times per month, doing presentations in primary schools, scout/guide groups, and club meet once a month as well, then will never need to touch the collimation

Even the attach pic in initial article, can be caused by parallax error, angle holding camera

If able to observe DSO clearly, then just leave alone

Only time need to collimate, if unable to focus clearly

I use laser collimator 

John  

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Well , finally the hour of truth has come. i.e the Cheshire CT from TS with CONCENTER tool test. Everything i left untouched from previous tweaking (laser show)

And here s the View through Cheshire CT.

IMG_0961.jpg.549412ed8761e4ba950f03dde7ca4abc.jpg

Through Concenter tool, Wonder if i ever will get those  rings aligned with primary to secondary and vice versa cos of the offset ?

IMG_0962.jpg.7fe584e41f6c038735604da7ef180c34.jpg

 

An an image after the previous laser tweak. The halo around the bright star is gleaming . Primary edges need tuning ? paint it rough black ? Next adventure ? Thanx much CS,

Rush

2 hrs L and 1 hr RGB with the prvious laser tweak test. Bright star core light streaks around. Sorry if its dirty crude processed , red gradient kill next time after serious extrem imaging:)

M51RGB.jpg.4642b1de93489b2f40ec85e6d7071815.jpg

 

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Posted (edited)
21 minutes ago, Rush said:

Well , finally the hour of truth has come. i.e the Cheshire CT from TS with CONCENTER tool test. Everything i left untouched from previous tweaking (laser show)

And here s the View through Cheshire CT.

IMG_0961.jpg.549412ed8761e4ba950f03dde7ca4abc.jpg

Through Concenter tool, Wonder if i ever will get those  rings aligned with primary to secondary and vice versa cos of the offset ?

An an image after the previous laser tweak. The halo around the bright star is gleaming . Primary edges need tuning ? paint it rough black ? Next adventure ? Thanx much CS,

Rush

2 hrs L and 1 hr RGB with the prvious laser tweak test. Bright star core light streaks around. Sorry if its dirty crude processed , red gradient kill next time after serious extrem imaging:)

 

It looks like you will not be able to see the primary mirror holders via Cheshire just like me! :)
Have fun! :) hehe

I hope I am not right :) as this makes life much more difficult....

I even tried to place my ASI224MC directly into the draw-tube, as 224MC body is actually 2" and it fits perfectly,

but... I did not like what I saw... Still cannot understand why the view was of-center...
Will repeat it next week will post some pics.

Edited by RolandKol
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That is quite a sight! Once you get it properly collimated it would be really interesting to compare your FWHM's before and after. The difference should be substantial!

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3 hours ago, RolandKol said:

It looks like you will not be able to see the primary mirror holders via Cheshire just like me! :)
Have fun! :) hehe

I hope I am not right :) as this makes life much more difficult....

I even tried to place my ASI224MC directly into the draw-tube, as 224MC body is actually 2" and it fits perfectly,

but... I did not like what I saw... Still cannot understand why the view was of-center...
Will repeat it next week will post some pics.

Swear i cant blame the drawtube or the eyepeace holder as Cheshire CT is held by a ring holder (no thumb screws)

I wish too u r not right, it was hours when all this began, slowly its turning into days ?

 

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i was struggling so hard to collimate my 130pds that i gave up imaging with  it for a few months.

recently, i was searching for sites to get some help collimating it and found one that gives a good alternative and it requires no tools to do the job.  I did try this method, but i don't know if my collimation is good or not, i'm about to post an image on the 130pds topic to see if anyone can check it for me.

this is the site: https://garyseronik.com/no-tools-telescope-collimation/   

you could this method a go to check your collimation as you already did it with the barlowed laser and the chesire.

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4 hours ago, Atreta said:

i was struggling so hard to collimate my 130pds that i gave up imaging with  it for a few months.

recently, i was searching for sites to get some help collimating it and found one that gives a good alternative and it requires no tools to do the job.  I did try this method, but i don't know if my collimation is good or not, i'm about to post an image on the 130pds topic to see if anyone can check it for me.

this is the site: https://garyseronik.com/no-tools-telescope-collimation/   

you could this method a go to check your collimation as you already did it with the barlowed laser and the chesire.

Simply defocus on the star... It is the best way to check

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