AT10RC on a Mach One


sarnoskypeter@...
 

Is anyone doing this that could share their results.

I would be at 39 lbs, before Dec balance (if needed)


I am a bit disappointed with my Edge 9.25, but that may be due to the fact that I cannot possibly reach the optimal 5.75" Sensor distance specified in the Celestron white paper with my current imaging train.


In any event I feel I should cut my losses and go with something that has a more user friendly setup on the imaging train.  (and a fixed primary)


Peter


Woody Schlom <woody@...>
 

Peter,
 
Will this be in a fixed permanent observatory or portable?
 
I ask because my experience with these GSO made RC scopes is that they don't hold collimation for beans when transported.  I have an 8" and don't use it because it requires re-collimation every time I pack and transport it -- and for quick setups that's a deal-breaker for me..
 
Woody
 

-----Original Message-----
From: ap-gto@... [mailto:ap-gto@...]
Sent: Wednesday, August 19, 2015 12:40 PM
To: ap-gto@...
Subject: [ap-gto] AT10RC on a Mach One

 

Is anyone doing this that could share their results.

I would be at 39 lbs, before Dec balance (if needed)


I am a bit disappointed with my Edge 9.25, but that may be due to the fact that I cannot possibly reach the optimal 5.75" Sensor distance specified in the Celestron white paper with my current imaging train.


In any event I feel I should cut my losses and go with something that has a more user friendly setup on the imaging train.  (and a fixed primary)


Peter


Maarten Vanleenhove <maarten.vanleenhove@...>
 

Hi,

I would seriously consider twice³ before buying an RC. It is extremely critical concerning collimation and the least you are off you will see astigmatism on-axis.
Collimating an RC is a work of art, especially with the GSO models that mechanically are nowhere near as precise as the premium brands. That also means that all the mechanical aids will not perform and the only real way of collimating an RC is with the star test. Remember there is not 1 but 2 optical axis that need to be set.
I've been struggling for over a year now to get it perfect and still the stars are not round everywhere in the field. (although progress was made)

kind regards,

Maarten Vanleenhove

Op 19/08/2015 om 21:39 schreef sarnoskypeter@... [ap-gto]:

 

Is anyone doing this that could share their results.

I would be at 39 lbs, before Dec balance (if needed)


I am a bit disappointed with my Edge 9.25, but that may be due to the fact that I cannot possibly reach the optimal 5.75" Sensor distance specified in the Celestron white paper with my current imaging train.


In any event I feel I should cut my losses and go with something that has a more user friendly setup on the imaging train.  (and a fixed primary)


Peter

No virus found in this message.
Checked by AVG - www.avg.com
Version: 2015.0.6086 / Virus Database: 4392/10467 - Release Date: 08/19/15



Ross Salinger <rgsalinger@...>
 

Since you don’t say what mount you’re using I would just echo Woody’s collimation comment. I struggled to get the collimation correct and eventually paid to have it done professionally. I took it 90 miles and it worked really well. I stored it out there at our club dark sky site for 6 weeks last year. When I removed it the collimation had shifted on my. That did it for me proving that it really needs to be collimated frequently. If you know how to do this with an RC or enjoy the challenge then why not! If you are more like me and just want things to work out of the box, I wouldn’t recommend one. I know that there are other people who have them, know how to collimate them and are happy. Assuming that you have a Mach 1 GTO I would say with regards to weight that I am now using a Meade 10”ACF F8 that guides on my Mach 1 at under .5 arc seconds. It’s about the same weight and not much more money. Incidentally, I’m not sure how much value you would really get with the 10” over the 8” and the closed tube design has to be more stable and not subject to dew. I can’t recall ever having to use my dew heater on my 8” (but I live in Southern California and avoid humid nights pretty much).

 

Rgrds-Ross

 

From: ap-gto@... [mailto:ap-gto@...]
Sent: Wednesday, August 19, 2015 12:40 PM
To: ap-gto@...
Subject: [ap-gto] AT10RC on a Mach One

 

 

Is anyone doing this that could share their results.

I would be at 39 lbs, before Dec balance (if needed)

 

I am a bit disappointed with my Edge 9.25, but that may be due to the fact that I cannot possibly reach the optimal 5.75" Sensor distance specified in the Celestron white paper with my current imaging train.

 

In any event I feel I should cut my losses and go with something that has a more user friendly setup on the imaging train.  (and a fixed primary)

 

Peter


Steve Reilly
 

I have used my Optical Guidance Systems 10” and 12.5” RC for years without collimation issues. I’ve taken them on the road and used them in the observatory. In fact John guaranties the scope will arrive collimated. See http://opticalguidancesystems.com/faq/ and look at that page for further info. Of course these aren’t the same scopes as the GSO’s either.

 

Steve

 

From: ap-gto@... [mailto:ap-gto@...]
Sent: Wednesday, August 19, 2015 3:54 PM
To: ap-gto@...
Subject: Re: [ap-gto] AT10RC on a Mach One

 

 

Hi,

I would seriously consider twice³ before buying an RC. It is extremely critical concerning collimation and the least you are off you will see astigmatism on-axis.
Collimating an RC is a work of art, especially with the GSO models that mechanically are nowhere near as precise as the premium brands. That also means that all the mechanical aids will not perform and the only real way of collimating an RC is with the star test. Remember there is not 1 but 2 optical axis that need to be set.
I've been struggling for over a year now to get it perfect and still the stars are not round everywhere in the field. (although progress was made)

kind regards,

Maarten Vanleenhove

Op 19/08/2015 om 21:39 schreef sarnoskypeter@... [ap-gto]:

 

Is anyone doing this that could share their results.

I would be at 39 lbs, before Dec balance (if needed)

 

I am a bit disappointed with my Edge 9.25, but that may be due to the fact that I cannot possibly reach the optimal 5.75" Sensor distance specified in the Celestron white paper with my current imaging train.

 

In any event I feel I should cut my losses and go with something that has a more user friendly setup on the imaging train.  (and a fixed primary)

 

Peter

No virus found in this message.
Checked by AVG - www.avg.com
Version: 2015.0.6086 / Virus Database: 4392/10467 - Release Date: 08/19/15

 


Maarten Vanleenhove <maarten.vanleenhove@...>
 

I have no doubt a premium brand has much better mechanical tolerances needed to achieve good collimation with tools. The price is also premium :) compared to our Chinese friends...

Kind regards,

Maarten



Op 19/08/2015 om 22:03 schreef 'Steven Reilly' sreilly24590@... [ap-gto]:

sues. I’ve taken th


sarnoskypeter@...
 

Thank you,

I am aware of the collimation issues, it would spend most of it's time on a pier in my driveway.


I would probably remove it and carry it 16 ft to store inside, occasionally transporting it.


I was more concerned with the AP's performance with that load.


As it stands now I have a very nice Edge that is collimated as well as it could possibly be with the Hotech advanced CT collimator, that still exhibits severe coma, or astig. (IMHO)

All I can assume here is that the sensor distance is critical or I have a very bad component.

In any event I want a relatively flat field at 2000mm and the RC seems to be the only option.


Well, that being said, I am aware that I could remove the moonlite focuser and have a one off extension machined to make it work after taking some critical measurements. Not too sure I want to do that.


Peter


Leonardo Orazi <pegaso0970@...>
 


All the best,
Leo

Inviato da iPhone

Il giorno 19/ago/2015, alle ore 21:40, "sarnoskypeter@... [ap-gto]" <ap-gto@...> ha scritto:

 

Is anyone doing this that could share their results.

I would be at 39 lbs, before Dec balance (if needed)


I am a bit disappointed with my Edge 9.25, but that may be due to the fact that I cannot possibly reach the optimal 5.75" Sensor distance specified in the Celestron white paper with my current imaging train.


In any event I feel I should cut my losses and go with something that has a more user friendly setup on the imaging train.  (and a fixed primary)


Peter


Steven
 

I use an RC with an outside focuser and CCD Inspector - easy to collimate, and very very very accurate - and since focus outside means it stays in collimation forever - unless I move it.

Steve E

________________________________________
From: ap-gto@yahoogroups.com [ap-gto@yahoogroups.com]
Sent: Wednesday, August 19, 2015 7:53 PM
To: ap-gto@yahoogroups.com
Subject: Re: [ap-gto] AT10RC on a Mach One

Hi,

I would seriously consider twice³ before buying an RC. It is extremely critical concerning collimation and the least you are off you will see astigmatism on-axis.
Collimating an RC is a work of art, especially with the GSO models that mechanically are nowhere near as precise as the premium brands. That also means that all the mechanical aids will not perform and the only real way of collimating an RC is with the star test. Remember there is not 1 but 2 optical axis that need to be set.
I've been struggling for over a year now to get it perfect and still the stars are not round everywhere in the field. (although progress was made)

kind regards,

Maarten Vanleenhove

Op 19/08/2015 om 21:39 schreef sarnoskypeter@yahoo.com<mailto:sarnoskypeter@yahoo.com> [ap-gto]:


Is anyone doing this that could share their results.

I would be at 39 lbs, before Dec balance (if needed)


I am a bit disappointed with my Edge 9.25, but that may be due to the fact that I cannot possibly reach the optimal 5.75" Sensor distance specified in the Celestron white paper with my current imaging train.


In any event I feel I should cut my losses and go with something that has a more user friendly setup on the imaging train. (and a fixed primary)


Peter

No virus found in this message.
Checked by AVG - www.avg.com<http://www.avg.com>
Version: 2015.0.6086 / Virus Database: 4392/10467 - Release Date: 08/19/15


topboxman
 

http://www.cloudynights.com/topic/242709-post-a-picture-of-your-cat/?p=3821053

 

He took fantastic images with this setup.

Peter


---In ap-gto@..., <sarnoskypeter@...> wrote :

Is anyone doing this that could share their results.

I would be at 39 lbs, before Dec balance (if needed)


I am a bit disappointed with my Edge 9.25, but that may be due to the fact that I cannot possibly reach the optimal 5.75" Sensor distance specified in the Celestron white paper with my current imaging train.


In any event I feel I should cut my losses and go with something that has a more user friendly setup on the imaging train.  (and a fixed primary)


Peter


Ned Smith <smithned753@...>
 

What is an "outside focuser"?

On Aug 19, 2015, at 4:19 PM, Steven Elliott steven447@hotmail.com [ap-gto] wrote:

I use an RC with an outside focuser and CCD Inspector - easy to collimate, and very very very accurate - and since focus outside means it stays in collimation forever - unless I move it.

Steve E

Ned Smith

N 34,53,38.13
W 85,28,17.10
Near Chattanooga, TN


Steve Reilly
 

Sounds like a focuser used on the rear cell instead of moving the secondary
to focus. Problem is using up precious back focus for the imaging train. But
then collimation shouldn't change just by focusing unless the mirrors aren't
held firmly in place. If there is that much mirror shift then there are
other problems as well. There was a SCT at Kitt Peak that lost collimation
just crossing the meridian and needed collimation. That's just poor
mechanically design or craftsmanship. There is mirror shift in all mirror
moving designs as I'm told but the amount is what is critical.

Steve

-----Original Message-----
From: ap-gto@yahoogroups.com [mailto:ap-gto@yahoogroups.com]
Sent: Thursday, August 20, 2015 8:07 AM
To: ap-gto@yahoogroups.com
Subject: Re: [ap-gto] AT10RC on a Mach One

What is an "outside focuser"?

On Aug 19, 2015, at 4:19 PM, Steven Elliott steven447@hotmail.com [ap-gto]
wrote:

I use an RC with an outside focuser and CCD Inspector - easy to collimate,
and very very very accurate - and since focus outside means it stays in
collimation forever - unless I move it.

Steve E

Ned Smith

N 34,53,38.13
W 85,28,17.10
Near Chattanooga, TN







------------------------------------

------------------------------------

To UNSUBSCRIBE, or for general information on the ap-gto list see
http://groups.yahoo.com/group/ap-gto
------------------------------------

Yahoo Groups Links


sarnoskypeter@...
 

Thanks for the link.

I am leaning toward a truss tube.

I believe they have dis engaged the primary from the focuser to eliminate any load flexing.


Peter


andyjwilson_uk
 

Hi Peter,

Not quite the same setup as you are thinking of, but I bought a 10" truss tube GSO RC a couple of months ago which is mounted on an AP1200. I previously had a 14" Meade which is why I had the AP1200. It barely notices the 10" RC.

The setup is for spectroscopy, so I'm not particularly bothered about off axis performance and I haven't paid much attention to it. I got the RC as I wanted a very stable setup with mirrors only (better for spectroscopy).

So far I am very pleased with the setup. Very little collimation needed and it holds it well. I have a feathertouch focuser which is fantastic and probably necessary for a heavy image train. The AP1200 is really doing the business holding everything rock solid and giving good pointing accuracy. This was one of my problems with my SCT setup and switching to an RC has really got things working a whole lot better. The AP1200 is really starting to shine in its performance for the first time since I bought it.

The only problem I have had is I could not reach focus with a 2" star diagonal and an eyepiece. I suspect this is to do with mirror positions from the factory setup. I've not bothered correcting it as I can reach focus fine for spectroscopy.

Best wishes,

Andy


Steven
 

Hi Ned

It's a Feathertouch focuser (or any other brand) that's installed outside the OTA. Use it instead of the 'inside' focuser.

Using one like that you can set the OTA focuser somewhere in the middle, and use the outside focuser to control focus. Then, once collimated, you shouldn't have to do that again because you never 'bother' the tube for anything.

Wish you luck.

Steve
________________________________________
From: ap-gto@yahoogroups.com [ap-gto@yahoogroups.com]
Sent: Thursday, August 20, 2015 12:07 PM
To: ap-gto@yahoogroups.com
Subject: Re: [ap-gto] AT10RC on a Mach One

What is an "outside focuser"?

On Aug 19, 2015, at 4:19 PM, Steven Elliott steven447@hotmail.com [ap-gto] wrote:

I use an RC with an outside focuser and CCD Inspector - easy to collimate, and very very very accurate - and since focus outside means it stays in collimation forever - unless I move it.

Steve E

Ned Smith

N 34,53,38.13
W 85,28,17.10
Near Chattanooga, TN







------------------------------------

------------------------------------

To UNSUBSCRIBE, or for general information on the ap-gto list
see http://groups.yahoo.com/group/ap-gto
------------------------------------

Yahoo Groups Links


Steven
 

Always be flexible and adaptable in your thinking.

Steve E
________________________________________
From: ap-gto@yahoogroups.com [ap-gto@yahoogroups.com]
Sent: Thursday, August 20, 2015 3:25 PM
To: ap-gto@yahoogroups.com
Subject: RE: [ap-gto] AT10RC on a Mach One

Sounds like a focuser used on the rear cell instead of moving the secondary
to focus. Problem is using up precious back focus for the imaging train. But
then collimation shouldn't change just by focusing unless the mirrors aren't
held firmly in place. If there is that much mirror shift then there are
other problems as well. There was a SCT at Kitt Peak that lost collimation
just crossing the meridian and needed collimation. That's just poor
mechanically design or craftsmanship. There is mirror shift in all mirror
moving designs as I'm told but the amount is what is critical.

Steve

-----Original Message-----
From: ap-gto@yahoogroups.com [mailto:ap-gto@yahoogroups.com]
Sent: Thursday, August 20, 2015 8:07 AM
To: ap-gto@yahoogroups.com
Subject: Re: [ap-gto] AT10RC on a Mach One

What is an "outside focuser"?

On Aug 19, 2015, at 4:19 PM, Steven Elliott steven447@hotmail.com [ap-gto]
wrote:

I use an RC with an outside focuser and CCD Inspector - easy to collimate,
and very very very accurate - and since focus outside means it stays in
collimation forever - unless I move it.

Steve E
Ned Smith

N 34,53,38.13
W 85,28,17.10
Near Chattanooga, TN

------------------------------------

------------------------------------

To UNSUBSCRIBE, or for general information on the ap-gto list see
http://groups.yahoo.com/group/ap-gto
------------------------------------

Yahoo Groups Links


rob
 

i used a tube AT10RC against a mach1 for a couple of years. it worked OK. seeing isn't spectacular here and so it's possible that under 'sharper' skies i would have had different results.

biggest problem with this OTA as others have pointed out is optomechanical. collimation can be difficult to do properly unless you have a camera with a sensor big enough to see the distortions at the edges of the frame. also since the mirror is attached to the focuser tube, it's next to impossible to guide without an OAG.

rob


Roth Ritter
 


For what it’s worth, the first thing I noticed even with my RCOS 10RCA f/7 was how tricky the collimation could be. The smallest possible crank of the rear collimation screws would make a mile of difference which made it a tedious process. But, once set it never needed a touch up, though it was a permanent installation. I guess my 2 cents here is that all makes of RCs can require a decent amount of patience in that department.

-R




Dark Atmospheres / a s t r o p h o t o g r a p h y \







On Aug 19, 2015, at 4:07 PM, Maarten Vanleenhove maarten.vanleenhove@... [ap-gto] <ap-gto@...> wrote:


I have no doubt a premium brand has much better mechanical tolerances needed to achieve good collimation with tools. The price is also premium :) compared to our Chinese friends...

Kind regards,

Maarten



Op 19/08/2015 om 22:03 schreef 'Steven Reilly' sreilly24590@... [ap-gto]:
sues. I’ve taken th