What scope and coma corrector are you using?

I have Sky-Watcher 150/750 scope, f/5 and Levenhuk Coma Corrector (I just recently finally got the required extension ring for astrophoto, will test as soon as the weather permit)   http://www.astrobin.com/295196/?nc=user

I've a Skywatcher 8" f/5 Newtonian without a coma corrector atm. My camera the Atik 314l+ gives a small fov.

David Goldstein:

I'm using an 8 inch f/4 TS ONTC Newtonian and the Skywatcher f/4 coma corrector, which is a rebranded GPU coma corrector.

Mike,

Can you speak to the advantages of the TS astrograph over the Astrotech/TPO/Skywatcher/Orion clones out there?  I know there is a carbon fiber tube used in the TS and what appears to be a better focuser, but I was wondering how much are the parts in the scope like what is found in the cheaper clones.

Thanks,

David

I used to own a GSO 8 inch f/4 about 9 years ago and the tube on this TS is considerably more sturdy.  My understanding is more recently "Chinese" 8 inch f/4 scopes have better tubes than my old one, so I can't really compare directly.  But I have to think the carbon fiber is better - just can't say if it makes a real difference.

I think the secondary holder and collimation bolts are similar to a nicer "Chinese" scope.  Probably no real advantage there.

The primary is mounted on a real mirror cell with multi-point support.  The mirror cell is mounted in such a way you can easily move it forwards or backwards in the tube to change your backfocus for different coma correctors.   Collimation is done with nice push pull system.  I think this is much nicer than the "Chinese" scopes I've seen.

The interior of the tube is black but I'm not convinced it is dark enough.  They did put flocking material across from the focuser.  I am going to flock the area around the primary as well.

The rings which come with the scope are the same as the rings I got on a Orion 8 inch f/5 Newtonian so nothing special there.

I use an Orion TOAG with my scope so I don't have a feel for the amount of flexure (or lack thereof).

I do know if I put a laser collimator in the focuser and move the scope around in alt/az that the laser dot stays centered in the primary dot.  In my old GSO it would move around as things flexed as the gravity vector changed as I moved the scope around.

TS was very easy to work with and I had excellent communications while they made the scope.  They asked me what focuser and coma corrector I wanted and then they drilled the carbon fiber tube.  Everything came out perfectly.  Any questions I had were answered within 24 hours (considering the time difference from USA to Germany).

My only regret is maybe I should have got the 10 inch f/4.   ;)

David Goldstein:

I'm using an 8 inch f/4 TS ONTC Newtonian and the Skywatcher f/4 coma corrector, which is a rebranded GPU coma corrector.

Mike,Can you speak to the advantages of the TS astrograph over the Astrotech/TPO/Skywatcher/Orion clones out there?  I know there is a carbon fiber tube used in the TS and what appears to be a better focuser, but I was wondering how much are the parts in the scope like what is found in the cheaper clones.

Thanks,

David

I used to own a GSO 8 inch f/4 about 9 years ago and the tube on this TS is considerably more sturdy.  My understanding is more recently "Chinese" 8 inch f/4 scopes have better tubes than my old one, so I can't really compare directly.  But I have to think the carbon fiber is better - just can't say if it makes a real difference.

I think the secondary holder and collimation bolts are similar to a nicer "Chinese" scope.  Probably no real advantage there.

The primary is mounted on a real mirror cell with multi-point support.  The mirror cell is mounted in such a way you can easily move it forwards or backwards in the tube to change your backfocus for different coma correctors.   Collimation is done with nice push pull system.  I think this is much nicer than the "Chinese" scopes I've seen.

The interior of the tube is black but I'm not convinced it is dark enough.  They did put flocking material across from the focuser.  I am going to flock the area around the primary as well.

The rings which come with the scope are the same as the rings I got on a Orion 8 inch f/5 Newtonian so nothing special there.

I use an Orion TOAG with my scope so I don't have a feel for the amount of flexure (or lack thereof).

I do know if I put a laser collimator in the focuser and move the scope around in alt/az that the laser dot stays centered in the primary dot.  In my old GSO it would move around as things flexed as the gravity vector changed as I moved the scope around.

TS was very easy to work with and I had excellent communications while they made the scope.  They asked me what focuser and coma corrector I wanted and then they drilled the carbon fiber tube.  Everything came out perfectly.  Any questions I had were answered within 24 hours (considering the time difference from USA to Germany).

My only regret is maybe I should have got the 10 inch f/4.   ;)

Thanks Mike for your in-depth reply.    Your comment about collimation staying centered is also probably directly related to the rigidity of the carbon fiber tube TS provides.  Not having seen one in person, all I can go by is commentary like yours.  Thanks again.  

Hi Andy,

Sorry for the late reply - I believe the focuser on nearly all scopes can be switched out. On a Newt especially, you can basically replace anything - the spider, either mirror, mirror cell, focuser… aside from the finder shoe, I've basically taken everything off my scope at one point or another (not all at the same time though). I honestly believe those ONTC scopes are made with GSO mirrors. Does GSO make their own 8" carbon fiber f/4 Newts? I highly recommend CF if you can afford it - the thermal stability, less tube flexure, and lighter weight are all big pluses. Hope this message didn't arrive too late, but if it did - what did you end up going with?

Chris

I used to have an 8 inch f5 Saxon (Skywatcher) and used a Baader Mpcc mkiii coma corrector with awesome results…
Then i noved on to a Skywatcher 10 inch f4 telescope and fou d out the MPCC does not perform the same at that ratio…. decided to install a Televue Paracorr and i couldn't be hapier… curvature with the Mpcc was 45% measured with ccd inspector,   now the Paracorr results in 16% curvature….

My stars are now tighter across the FOV and i am sure the telescope is performing better than ever….

I started out with a Vixen R200SS 8" f/4 which I tried to improve in all possible ways. Finally, the only thing left of the original scope were the mirrors. Sadly, the frankenvixen never performed particularly well, so I ended up getting a second hand Epsilon 180ed 8" f2/8. It has had its share of problems as well, but now it seems I'm finally getting it dialled in. Collimating this bucket is pretty unforgiving.

Clear skies!
Ginge

Hello

I use Skywatchers 130 PDS (130/650) with Skywatcher Coma Corrector (x0.9). Well, maybe the slowest among the fast ones with f 5 , but I am happy with it 

An old topic, i just bought 8" F5 [3 months ago or 4], it is Meade LX70 model, and only recently i got collimator [Cheshire] and Skywatcher F4 Aplanatic coma corrector.

I still didn't use the scope at all, still in the box, but  i am not sure if the collimator i bought is good enough as i heard about laser collimator, and i didn't have the time or reason to use it yet, i bought a Mak in same period so i got busy with this more, and i try to test my filters first with ST80, then sooner or later i will take out this Newtonian for use, and i am planning to buy another newtonian in the future, but 6" F4 if available or even F2.8, but i am not in rush.

Pat Rodgers:
You've got the best collimator Tareq. Plenty of you tube videos showing how to use it, if your stuck.Good luck with all the scopes.

Pat.

Hey Pat,

Thank you for your post and sorry it is late reply.

Still didn't use the Newt, got busy last 2 months ago, but now i am really planning to take it out and test collimating at day time, but i feel it is pointless if i won't take it out for imaging, and it is very very hot outside now, even my cooled camera can't resist it, so maybe i will wait a bit more, but i have one question only, if i tested my collimating and i did set it correctly, do i need to re-collimate it later even if i didn't use it? Is there a way that i don't need to collimate it over and over again but only once or twice every many use?

Tareq

I'm using an 8 inch f/4 TS ONTC Newtonian and the Skywatcher f/4 coma corrector, which is a rebranded GPU coma corrector.

I'm considering purchasing a TS UNC F/4 8" Newtonian. Have you been happy with the scope and coma corrector? I've asked TS about getting the Baader Mk3 instead of the TS version...we'll see what they come back with.
cheers
Gary

I have a TS ONTC 12” f5 with a carbon tube and my own Moonlite focuser. It certainly is a rigid piece of kit and doesn’t change collimating when moved around (laser collimator) there is very little focus change once all cooled down which used to bug me no end with my old homemade Aluminium tube 14”.
I can certainly vouch for TS, they shipped me an f4 by mistake and did everything they could to get me the f5 replacement ASAP, great service.
I use a Baader MPCC Mk II which I’m happy with for the moment but would be interested to look at a better replacement.