Author Topic: Despite best efforts to collimate scope, stars look like planets - suggestions?  (Read 5265 times)

iam4208

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Hi David, sounds like a plan. Let's go for it. I'll PM you my mobile number and you can text me your address. Thanks[emoji846]


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Sky-Watcher Skyliner-250PX FlexTube Parabolic Truss-Tube Dobsonian with Baader Hyperion 36, 21, 13 and 8mm EPs and a 2x Barlow.
Telrad and RACI finder scope for finding objects the good ol' fashioned way:-)

SpookyKatt

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can you take a picture through the scope with your camera/phone to show us what it
looks like ?

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Tal 200K and Tal 100R
Equinox 80 and Orion 80
Skywatcher 150mm Refractor
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perthskies

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Hi David, sounds like a plan. Let's go for it. I'll PM you my mobile number and you can text me your address. Thanks[emoji846]


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PM'd and messaged you - Looking forward to a wee meet up

David
12" Goto Dob - wee grab 'n go refractor
Gloves - silly hat 3 pairs of binos and nae sense.

iam4208

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can you take a picture through the scope with your camera/phone to show us what it
looks like ?
Hi good to hear from you. I only have one pic showing the secondary mirror through the focusser tube and can't remember if it was taken before I started.  But let me know what you think.
I'm going up to see David on Saturday and will post a progress report.


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Sky-Watcher Skyliner-250PX FlexTube Parabolic Truss-Tube Dobsonian with Baader Hyperion 36, 21, 13 and 8mm EPs and a 2x Barlow.
Telrad and RACI finder scope for finding objects the good ol' fashioned way:-)

SpookyKatt

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Thanks for that, well the camera's a bit offset and updside down so its hard to know if there's anything wrong as
I'm sure you've collimated it via the guide ok. If the camera was flush I'd say from that image that the secondary
needs to go down and in a little inwards a bit....in the direction of the first image. 


Then once adjusted and looking down the draw tube it should be centered vertically as it were but a little foward
horizontially in the direction of the length of the tube if its a fast Newt which I think it is as its around f5 is it
not ?  Like I mocked up in the second image.

But as I say, I'm sure you've done it right and its just the effect of a camera phone lens.


« Last Edit: March 03, 2017, 04:28:21 PM by SpookyKatt »
HEQ5/EQ5
Tal 200K and Tal 100R
Equinox 80 and Orion 80
Skywatcher 150mm Refractor
Modded Canon EOS 400D
DFK-31AF03

iam4208

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Hi Kat, great advice.  I'll get before and after pics tonight when wrestling with it.  Thanks again[emoji846]


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Sky-Watcher Skyliner-250PX FlexTube Parabolic Truss-Tube Dobsonian with Baader Hyperion 36, 21, 13 and 8mm EPs and a 2x Barlow.
Telrad and RACI finder scope for finding objects the good ol' fashioned way:-)

iam4208

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Totally forgot to take any pictures, but David reckons he has fixed the collimation of my scope and watching him go about it, I'm pretty confident he has too.  However, it wasn't clear enough to do a star test.  Hopefully, there will be a chance in the next week.
The main issues were that the secondary mirror wasn't central on the tube and it wasn't centred under the focusser, so Kathleen was on the right track even with my dodgy photo.  David adjusted the spider vanes and the centre screw.  He also adjusted the primary, so that it was not rock bottom, but moved it enough to allow adjustment in either direction. I learnt a lot from watching David and listening to his advice. It was great to meet Martin and Peter too and I stayed on for a bit to chat.  I also met a very old friend, which was a nice surprise - Lorne's old goto Dob!!  Although I hogged a good bit of the drinking time, I'm sure the alcohol got flowing properly after I left. Here's hoping you three are not too ill in the morning and I hope to see you again soon. Thanks everyone for helping me go from [emoji848] to [emoji2]


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Sky-Watcher Skyliner-250PX FlexTube Parabolic Truss-Tube Dobsonian with Baader Hyperion 36, 21, 13 and 8mm EPs and a 2x Barlow.
Telrad and RACI finder scope for finding objects the good ol' fashioned way:-)

SpookyKatt

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good news, hopefully thats the issue resolved.
HEQ5/EQ5
Tal 200K and Tal 100R
Equinox 80 and Orion 80
Skywatcher 150mm Refractor
Modded Canon EOS 400D
DFK-31AF03

perthskies

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Totally forgot to take any pictures, but David reckons he has fixed the collimation of my scope and watching him go about it, I'm pretty confident he has too.  However, it wasn't clear enough to do a star test.  Hopefully, there will be a chance in the next week.
The main issues were that the secondary mirror wasn't central on the tube and it wasn't centred under the focusser, so Kathleen was on the right track even with my dodgy photo.  David adjusted the spider vanes and the centre screw.  He also adjusted the primary, so that it was not rock bottom, but moved it enough to allow adjustment in either direction. I learnt a lot from watching David and listening to his advice. It was great to meet Martin and Peter too and I stayed on for a bit to chat.  I also met a very old friend, which was a nice surprise - Lorne's old goto Dob!!  Although I hogged a good bit of the drinking time, I'm sure the alcohol got flowing properly after I left. Here's hoping you three are not too ill in the morning and I hope to see you again soon. Thanks everyone for helping me go from [emoji848] to [emoji2]


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a little bit tender today, Pete and Martyn have gone to Bridge of Earn to buy breakfast stuff as MARTYN FORGOT to bring brekky stuff lol
12" Goto Dob - wee grab 'n go refractor
Gloves - silly hat 3 pairs of binos and nae sense.

iam4208

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Totally forgot to take any pictures, but David reckons he has fixed the collimation of my scope and watching him go about it, I'm pretty confident he has too.  However, it wasn't clear enough to do a star test.  Hopefully, there will be a chance in the next week.
The main issues were that the secondary mirror wasn't central on the tube and it wasn't centred under the focusser, so Kathleen was on the right track even with my dodgy photo.  David adjusted the spider vanes and the centre screw.  He also adjusted the primary, so that it was not rock bottom, but moved it enough to allow adjustment in either direction. I learnt a lot from watching David and listening to his advice. It was great to meet Martin and Peter too and I stayed on for a bit to chat.  I also met a very old friend, which was a nice surprise - Lorne's old goto Dob!!  Although I hogged a good bit of the drinking time, I'm sure the alcohol got flowing properly after I left. Here's hoping you three are not too ill in the morning and I hope to see you again soon. Thanks everyone for helping me go from [emoji848] to [emoji2]


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a little bit tender today, Pete and Martyn have gone to Bridge of Earn to buy breakfast stuff as MARTYN FORGOT to bring brekky stuff lol
Oops! I hope he offered cook AND wash up as penance[emoji846]


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Sky-Watcher Skyliner-250PX FlexTube Parabolic Truss-Tube Dobsonian with Baader Hyperion 36, 21, 13 and 8mm EPs and a 2x Barlow.
Telrad and RACI finder scope for finding objects the good ol' fashioned way:-)

iam4208

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Got the scope out for a very short test under the clear, but starting to cloud over skies earlier and the news is good[emoji106][emoji106][emoji898][emoji898]
I can see stars again!!
Great result and a big, big thank you to David[emoji6]



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Sky-Watcher Skyliner-250PX FlexTube Parabolic Truss-Tube Dobsonian with Baader Hyperion 36, 21, 13 and 8mm EPs and a 2x Barlow.
Telrad and RACI finder scope for finding objects the good ol' fashioned way:-)

perthskies

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Got the scope out for a very short test under the clear, but starting to cloud over skies earlier and the news is good[emoji106][emoji106][emoji898][emoji898]
I can see stars again!!
Great result and a big, big thank you to David[emoji6]



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Great news Iain, glad to have been able to help. The offer still stands for mirror cleaning etc., so just keep me posted and we can get together and spend a bit more time fine tuning the dob.

David
12" Goto Dob - wee grab 'n go refractor
Gloves - silly hat 3 pairs of binos and nae sense.

iam4208

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Got the scope out for a very short test under the clear, but starting to cloud over skies earlier and the news is good[emoji106][emoji106][emoji898][emoji898]
I can see stars again!!
Great result and a big, big thank you to David[emoji6]



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Great news Iain, glad to have been able to help. The offer still stands for mirror cleaning etc., so just keep me posted and we can get together and spend a bit more time fine tuning the dob.

David

I just want to get out there with it now and see how it goes :)
Sky-Watcher Skyliner-250PX FlexTube Parabolic Truss-Tube Dobsonian with Baader Hyperion 36, 21, 13 and 8mm EPs and a 2x Barlow.
Telrad and RACI finder scope for finding objects the good ol' fashioned way:-)

iam4208

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The scope got a proper try out tonight and with a little help from Neil and his super duper collimator, we managed to get the scope properly collimated. My laser collimator looks a bit off, so I will have to check it is collimated and consider getting a self-centering adapter.
I had lost a bit of enthusiasm for the hobby after the scope issues and the dreadful season we've had, but I enjoyed the session tonight and hope it wasn't the last of the season[emoji846]


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Sky-Watcher Skyliner-250PX FlexTube Parabolic Truss-Tube Dobsonian with Baader Hyperion 36, 21, 13 and 8mm EPs and a 2x Barlow.
Telrad and RACI finder scope for finding objects the good ol' fashioned way:-)

BeerMe

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Great news Ian, I think the sight of your scope that night at Harperrigg, even though it wasn't operational, really cranked up my aperture fever and resolved me to get something in that range too.  Hopefully, I might have my own 10" in a couple of weeks and we can maybe get a side by side before the season finishes :-)


Regardless, I'm glad you're back up and running again 👍
Paul

Heritage 130p and a few bits n [eye]pieces