Field Flattener


michael mccann
 

Hi 
Not really a GTO question, but your CCDT67 CCD Telecompressor was recommended as a Flattener for use with my Astro-tech RC 14” truss.  I was wondering if anyone could comment on the use of the flattener with 14” RC with f8.  

Thanks 

Cheers 


Steven Panish
 

I'm also interested.  I'm considering a GSO 10" truss RC and would need a flattener/reducer.

Steve

On Tue, Dec 21, 2021 at 4:32 PM michael mccann via groups.io <mmccawsprojects=icloud.com@groups.io> wrote:
Hi 
Not really a GTO question, but your CCDT67 CCD Telecompressor was recommended as a Flattener for use with my Astro-tech RC 14” truss.  I was wondering if anyone could comment on the use of the flattener with 14” RC with f8.  

Thanks 

Cheers 


George
 

Steve,

 

The CCDT67 is a telecompressor; it is not a flattener/corrector.    Also, it is not designed to cover a full frame sensor.

 

Regards,

 

George

 

George Whitney

Astro-Physics, Inc.

Phone:  815-222-6538 (direct line)

Phone:  815-282-1513 (office)

Email:  george@...

 

From: main@ap-gto.groups.io <main@ap-gto.groups.io> On Behalf Of Steven Panish
Sent: Wednesday, December 22, 2021 10:26 AM
To: main@ap-gto.groups.io
Subject: Re: [ap-gto] Field Flattener

 

I'm also interested.  I'm considering a GSO 10" truss RC and would need a flattener/reducer.

 

Steve

 

On Tue, Dec 21, 2021 at 4:32 PM michael mccann via groups.io <mmccawsprojects=icloud.com@groups.io> wrote:

Hi 

Not really a GTO question, but your CCDT67 CCD Telecompressor was recommended as a Flattener for use with my Astro-tech RC 14” truss.  I was wondering if anyone could comment on the use of the flattener with 14” RC with f8.  

 

Thanks 

 

Cheers 


Glenn
 

I have this one for my 10-inch RC but haven’t tried it yet. It is an 0.8x reducer that is supposed to provide excellent field correction for large sensors. 


https://www.teleskop-express.de/shop/product_info.php/info/p11145_TS-Optics-RC-0-8x-Corrector-Reducer-for-Ritchey-Chretien---big-sensors---M68-connection.html

Kind regards, 

Glenn Diekmann 


Dean S
 

I used  this reducer with my 10” AstroTech and it did fine, but with a 4020 CCD chip.  Doubt it would work well for much bigger size.
 
Some of my pics with it are at  www.astroimagers.com/DeanS
 
Dean
 
 

From: Steven Panish
Sent: Wednesday, December 22, 2021 11:26 AM
To: main@ap-gto.groups.io
Subject: Re: [ap-gto] Field Flattener
 
I'm also interested.  I'm considering a GSO 10" truss RC and would need a flattener/reducer.
 
Steve
 
On Tue, Dec 21, 2021 at 4:32 PM michael mccann via groups.io <mmccawsprojects@...> wrote:
Hi 
Not really a GTO question, but your CCDT67 CCD Telecompressor was recommended as a Flattener for use with my Astro-tech RC 14” truss.  I was wondering if anyone could comment on the use of the flattener with 14” RC with f8. 

Thanks

Cheers




Avast logo

This email has been checked for viruses by Avast antivirus software.
www.avast.com



Emilio J. Robau, P.E.
 

I wanted to add my two cents. 

The folks at AP are somewhat eccentric with respect to round stars at all corners everywhere and quality of course.  We would not want them to be anything else.   

However, I have to say that I use the AP27TVPH with my 12" GSO Truss RC and I have to comment that I love it and it does fine with my APS-H.  It is a reducer and as a result has some element of correction to it.   The circle of illumination is larger than the CCD T67.  I use this device on both of my Chinese scopes, the RC and the ES 127 FCD 100 and I can say it is not perfect for sure, but it produces some nice images.   I really like the product.  I could recommend it for the intended use posted here.

I doubt it would produce a good field on a full frame chip.  However, as large as an APS-H, which is larger than an APS-C it does just fine.  Personally I love it until such time as Roland can make my 130GTX and I can sell the ES.  


Emilio J. Robau, P.E.
 

I forgot, 
If I ever get the 130 GTX I will still keep my GSO RC.  I really like the thing.  I must have gotten a good sample.   I have taken it apart and know it inside and out.  It really is a good learning scope for tinkerers who don't have the cash for the more expensive RCs and want larger aperture and longer FL.  That said, I do have a stack of cash ready for an AP scope anytime anywhere.  Recently, thanks to an off topic comment here in which Dr. Rolando diagnosed the problem posted by another user, I was able to eliminate some superfluous reflections by simply extending the baffle.  Finally, I also have a field flattener from TS for the scope, but honestly, I just keep the AP27TVPH on it and enjoy the larger field of view and the faster scope.