Reflection in image


Robert Chozick
 

What would cause the refections in this image?  It has been suggested to be a reflection in one of the t-thread  or 2 inch extensions.  I also place a 2 inch UV/IR filter at the end of the AP CCDT67 tele compressor.  The order is ZWO 2600 color camera + t-thread extensions  + t-thread to 2 inch adapter + 2 inch extensions + CCDT67 + 2 inch Baader UV/IR filter.   I space it to be a .67 reduction factor.  Any help diagnosing this would be appreciated.

https://pbase.com/rchozick/image/171993637

Image cropped without reflection:


Robert


Roland Christen
 

You don't say what scope that is. Looks like a light leak around a secondary baffle.

Rolando

-----Original Message-----
From: Robert Chozick via groups.io <rchozick@...>
To: main@ap-gto.groups.io
Sent: Sun, Sep 26, 2021 2:09 pm
Subject: [ap-gto] Reflection in image

What would cause the refections in this image?  It has been suggested to be a reflection in one of the t-thread  or 2 inch extensions.  I also place a 2 inch UV/IR filter at the end of the AP CCDT67 tele compressor.  The order is ZWO 2600 color camera + t-thread extensions  + t-thread to 2 inch adapter + 2 inch extensions + CCDT67 + 2 inch Baader UV/IR filter.   I space it to be a .67 reduction factor.  Any help diagnosing this would be appreciated.

https://pbase.com/rchozick/image/171993637

Image cropped without reflection:


Robert

--
Roland Christen
Astro-Physics


Robert Chozick
 

Thanks. It is an 8 inch RC. 

Robert 


On Sep 27, 2021, at 10:10 AM, Roland Christen via groups.io <chris1011@...> wrote:


You don't say what scope that is. Looks like a light leak around a secondary baffle.

Rolando

-----Original Message-----
From: Robert Chozick via groups.io <rchozick@...>
To: main@ap-gto.groups.io
Sent: Sun, Sep 26, 2021 2:09 pm
Subject: [ap-gto] Reflection in image

What would cause the refections in this image?  It has been suggested to be a reflection in one of the t-thread  or 2 inch extensions.  I also place a 2 inch UV/IR filter at the end of the AP CCDT67 tele compressor.  The order is ZWO 2600 color camera + t-thread extensions  + t-thread to 2 inch adapter + 2 inch extensions + CCDT67 + 2 inch Baader UV/IR filter.   I space it to be a .67 reduction factor.  Any help diagnosing this would be appreciated.

https://pbase.com/rchozick/image/171993637

Image cropped without reflection:


Robert

--
Roland Christen
Astro-Physics


Roland Christen
 

-----Original Message-----
From: Robert Chozick via groups.io <rchozick@...>
To: main@ap-gto.groups.io
Sent: Mon, Sep 27, 2021 10:24 am
Subject: Re: [ap-gto] Reflection in image

Thanks. It is an 8 inch RC. 

Robert 


On Sep 27, 2021, at 10:10 AM, Roland Christen via groups.io <chris1011@...> wrote:


You don't say what scope that is. Looks like a light leak around a secondary baffle.

Rolando

-----Original Message-----
From: Robert Chozick via groups.io <rchozick@...>
To: main@ap-gto.groups.io
Sent: Sun, Sep 26, 2021 2:09 pm
Subject: [ap-gto] Reflection in image

What would cause the refections in this image?  It has been suggested to be a reflection in one of the t-thread  or 2 inch extensions.  I also place a 2 inch UV/IR filter at the end of the AP CCDT67 tele compressor.  The order is ZWO 2600 color camera + t-thread extensions  + t-thread to 2 inch adapter + 2 inch extensions + CCDT67 + 2 inch Baader UV/IR filter.   I space it to be a .67 reduction factor.  Any help diagnosing this would be appreciated.

https://pbase.com/rchozick/image/171993637

Image cropped without reflection:


Robert

--
Roland Christen
Astro-Physics

--
Roland Christen
Astro-Physics


Emilio J. Robau, P.E.
 

Robert,

I have been fighting the same thing on my 12"GSO RC for years.   I have a truss system.   If you find a remedy, please let me know.  Recently I placed protostar flock on the tube portion of the scope to make it even darker, but I doubt it will help.  It seems to happen when my scope is pointed between 10 degrees and 30 or so degrees, and is less frequent when I am pointed more towards the zenith.  I think it also happens when there is a bright star nearby.


 

you might try extending the baffle a few inches (or experiment) and see if you can eliminate it?

I had a similar issue on my cdk20. After I isolated the cause using paper baffle extensions, my solution was to 3d print a baffle extension and attach it 

Problem gone. 

Brian


On Mon, Sep 27, 2021 at 10:55 AM Emilio J. Robau, P.E. <ejr@...> wrote:
Robert,

I have been fighting the same thing on my 12"GSO RC for years.   I have a truss system.   If you find a remedy, please let me know.  Recently I placed protostar flock on the tube portion of the scope to make it even darker, but I doubt it will help.  It seems to happen when my scope is pointed between 10 degrees and 30 or so degrees, and is less frequent when I am pointed more towards the zenith.  I think it also happens when there is a bright star nearby.



--
Brian 



Brian Valente


Stone, Jack G
 

There were some articles written on the 12” when it was first released.

One of which was a baffle leak – I tried to google it but to no avail.  But it was reported both in the US and UK predominantly –

Also was the mirror support design – there were modifications as well, seems as though there were some distortions.

There were other mentions as well – If anyone has any references to these articles – would be appreciated.

 

 

 

From: main@ap-gto.groups.io <main@ap-gto.groups.io> On Behalf Of Brian Valente
Sent: Monday, September 27, 2021 11:14 AM
To: main@ap-gto.groups.io
Subject: Re: [ap-gto] Reflection in image

 

you might try extending the baffle a few inches (or experiment) and see if you can eliminate it?

 

I had a similar issue on my cdk20. After I isolated the cause using paper baffle extensions, my solution was to 3d print a baffle extension and attach it 

 

Problem gone. 

 

Brian

 

On Mon, Sep 27, 2021 at 10:55 AM Emilio J. Robau, P.E. <ejr@...> wrote:

Robert,

I have been fighting the same thing on my 12"GSO RC for years.   I have a truss system.   If you find a remedy, please let me know.  Recently I placed protostar flock on the tube portion of the scope to make it even darker, but I doubt it will help.  It seems to happen when my scope is pointed between 10 degrees and 30 or so degrees, and is less frequent when I am pointed more towards the zenith.  I think it also happens when there is a bright star nearby.


 

--

Brian 

 

 

 

Brian Valente


Emilio J. Robau, P.E.
 

I don't want to goober up the AP list too much, and I do own an AP1600 upon which the scope sits, so reference to the baffle leak article would help my baffling artifact.  


Andrea Lucchetti
 

Wow, 
a telescope like the CDK20 can have a baffling issue?
I can understand the problem in lesser telescope but in the PW CDK is very strange, no?
you should propose them your retrofit kit :-)
Andrea


 

>>>a telescope like the CDK20 can have a baffling issue?

Yeah, but I don't want to get into any bashing here

I think they recently changed their baffle design, and it turns out there were some issues.

we did send them the feedback and generally Planewave has been great about it, and our hosting partner Obstech has been extremely good at diagnostics and interim fixes.

As with a lot of things astronomical, i find it works better when i approach it as a partnership


Brian


On Mon, Sep 27, 2021 at 11:39 AM Andrea Lucchetti <andlucchett@...> wrote:
Wow, 
a telescope like the CDK20 can have a baffling issue?
I can understand the problem in lesser telescope but in the PW CDK is very strange, no?
you should propose them your retrofit kit :-)
Andrea



--
Brian 



Brian Valente


Bill Long
 

John Hayes reported something similar with the baffle on his 20" CDK. IIRC they sent him a newly designed one.


From: main@ap-gto.groups.io <main@ap-gto.groups.io> on behalf of Andrea Lucchetti <andlucchett@...>
Sent: Monday, September 27, 2021 11:38 AM
To: main@ap-gto.groups.io <main@ap-gto.groups.io>
Subject: Re: [ap-gto] Reflection in image
 
Wow, 
a telescope like the CDK20 can have a baffling issue?
I can understand the problem in lesser telescope but in the PW CDK is very strange, no?
you should propose them your retrofit kit :-)
Andrea


Andrea Lucchetti
 

yes, it can always happen. 
fully agree with the approach.


Emilio J. Robau, P.E.
 

Maybe this will put an end to the GSO discussions.   I did some searching.  Teleskop Service sells a baffle addition for the stock baffle sold on GSO RCs which were shown to have light leaks around the secondary baffle and produce similar artifacts to what I experienced and what Robert is experiencing.  It is called a light shade baffle and they make them for several size scopes.  Apparently the issue was detected back in 2017 by a gentleman named Knute H. Shaffner and in collaboration with Teleskop Service TS started making the baffles.  I am ordering one for my 12" GSO and I suppose I could experiment an extension to the baffle, but that would take some time and time is money and is better spent under clear skies.

Thanks Rolando for the diagnosis and the rest of the gang for chiming in.  I hope this cures the very annoying artifact I have lived with for a while.  I admit, I do like my poor man's RC.  Hopefully I will like it even more for now and until I can upgrade.


Robert Chozick
 

Thanks Roland. Someone had already suggested to me that it could be a need for extension of the secondary by about half an inch. I have used the scope many times and this is the first time this is happened. I think there was a bright star nearby. The iris is close to one of the main stars in Cepheus.   

Robert 


On Sep 27, 2021, at 1:14 PM, Brian Valente <bvalente@...> wrote:


you might try extending the baffle a few inches (or experiment) and see if you can eliminate it?

I had a similar issue on my cdk20. After I isolated the cause using paper baffle extensions, my solution was to 3d print a baffle extension and attach it 

Problem gone. 

Brian


On Mon, Sep 27, 2021 at 10:55 AM Emilio J. Robau, P.E. <ejr@...> wrote:
Robert,

I have been fighting the same thing on my 12"GSO RC for years.   I have a truss system.   If you find a remedy, please let me know.  Recently I placed protostar flock on the tube portion of the scope to make it even darker, but I doubt it will help.  It seems to happen when my scope is pointed between 10 degrees and 30 or so degrees, and is less frequent when I am pointed more towards the zenith.  I think it also happens when there is a bright star nearby.



--
Brian 



Brian Valente


 

Please keep us posted Emilio

I have 2 GSO RCs, they are mostly sitting in the corner, but I may be inspired to re-energize them!

On Mon, Sep 27, 2021 at 12:31 PM Emilio J. Robau, P.E. <ejr@...> wrote:
Maybe this will put an end to the GSO discussions.   I did some searching.  Teleskop Service sells a baffle addition for the stock baffle sold on GSO RCs which were shown to have light leaks around the secondary baffle and produce similar artifacts to what I experienced and what Robert is experiencing.  It is called a light shade baffle and they make them for several size scopes.  Apparently the issue was detected back in 2017 by a gentleman named Knute H. Shaffner and in collaboration with Teleskop Service TS started making the baffles.  I am ordering one for my 12" GSO and I suppose I could experiment an extension to the baffle, but that would take some time and time is money and is better spent under clear skies.

Thanks Rolando for the diagnosis and the rest of the gang for chiming in.  I hope this cures the very annoying artifact I have lived with for a while.  I admit, I do like my poor man's RC.  Hopefully I will like it even more for now and until I can upgrade.



--
Brian 



Brian Valente


Robert Chozick
 

I just reread the other mail that he sent. I thought he meant extend the secondary out but now I understand extend the secondary baffle. 

Robert 


On Sep 27, 2021, at 2:34 PM, Robert Chozick via groups.io <rchozick@...> wrote:

Thanks Roland. Someone had already suggested to me that it could be a need for extension of the secondary by about half an inch. I have used the scope many times and this is the first time this is happened. I think there was a bright star nearby. The iris is close to one of the main stars in Cepheus.   

Robert 


On Sep 27, 2021, at 1:14 PM, Brian Valente <bvalente@...> wrote:


you might try extending the baffle a few inches (or experiment) and see if you can eliminate it?

I had a similar issue on my cdk20. After I isolated the cause using paper baffle extensions, my solution was to 3d print a baffle extension and attach it 

Problem gone. 

Brian


On Mon, Sep 27, 2021 at 10:55 AM Emilio J. Robau, P.E. <ejr@...> wrote:
Robert,

I have been fighting the same thing on my 12"GSO RC for years.   I have a truss system.   If you find a remedy, please let me know.  Recently I placed protostar flock on the tube portion of the scope to make it even darker, but I doubt it will help.  It seems to happen when my scope is pointed between 10 degrees and 30 or so degrees, and is less frequent when I am pointed more towards the zenith.  I think it also happens when there is a bright star nearby.



--
Brian 



Brian Valente


Martin Magnan
 

Hello

"t-thread extensions  + t-thread to 2 inch adapter + 2 inch extensions + CCDT67"

I once had a very similar setup and the internal reflection was caused by a "shiny" adapter. The problem was solved by flocking the inside of the adapter with black hockey tape.

Martin


Robert Chozick
 

I think the reflection pattern and size would be different if it were one of the extension tubes. 


On Sep 27, 2021, at 3:11 PM, Martin Magnan <martin.magnan@...> wrote:

Hello

"t-thread extensions  + t-thread to 2 inch adapter + 2 inch extensions + CCDT67"

I once had a very similar setup and the internal reflection was caused by a "shiny" adapter. The problem was solved by flocking the inside of the adapter with black hockey tape.

Martin