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SCT corrector advice

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#1 DavidHickey

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Posted 27 June 2019 - 10:08 AM

I have a Meade 8" LX50 I bought in 1999, which is deforked and rides on an Atlas Pro mount.  I put a Moonlite focuser on it last year to enter the autofocus world and be able to deal with the mirror flop.  Imaging is with an ASI1600MM + filter wheel + ZWO OAG.  I have a Meade 6.3 reducer/corrector as well.

 

No matter how much I adjust the backfocus I've never felt like I could get the Meade reducer set up quite right.  There always seems to be coma and curvature around the edge of the frame.  I've considered selling the LX50 and replacing it with an 8" ACF tube to get the UHTC and ACF optics plus the mirror lock.  I'd be ok with imaging at f/10 with the ACF as I do ok guiding with the OAG and this is used mainly for planetary and small DSOs anyway (refractor for the larger targets).  That said, I'm wondering if the better option might be to replace the Meade reducer/corrector with something like the Starizona SCT Corrector II (https://starizona.co...oma-corrector)?  It's $399, but if that would do the trick then I'd be ok spending the money for it.  With the 4/3 sensor on the ASI1600 I don't know that I'd reap all the benefits of the ACF design in the first place and being in the autofocus world has largely mitigated the mirror flop issue.

 

Any thoughts?

 

Thanks,

Dave



#2 Stephanh

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Posted 27 June 2019 - 10:44 AM

The starizona reducer/flattener works great with a  celestron C8.  Almost perfect stars right into the corners of images. It was a must cheaper solution for me than getting an HD scope.  I use the 1600MM camera.   See below,  very little cropping was applied, just enough to get rid of the dithering smear on the edges.

Attached Thumbnails

  • M81 Stephanh_cloudy nights.jpg

Edited by Stephanh, 27 June 2019 - 12:44 PM.

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#3 DavidHickey

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Posted 28 June 2019 - 04:21 PM

The starizona reducer/flattener works great with a celestron C8. Almost perfect stars right into the corners of images. It was a must cheaper solution for me than getting an HD scope. I use the 1600MM camera. See below, very little cropping was applied, just enough to get rid of the dithering smear on the edges.


Thanks for the response. That’s a nice image.

Dave

#4 starman876

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Posted 28 June 2019 - 08:01 PM

The starizona reducer/flattener works great with a  celestron C8.  Almost perfect stars right into the corners of images. It was a must cheaper solution for me than getting an HD scope.  I use the 1600MM camera.   See below,  very little cropping was applied, just enough to get rid of the dithering smear on the edges.

that is a great image.


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#5 925chicago

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Posted 11 July 2019 - 07:46 AM

The starizona reducer/flattener works great with a  celestron C8.  Almost perfect stars right into the corners of images. It was a must cheaper solution for me than getting an HD scope.  I use the 1600MM camera.   See below,  very little cropping was applied, just enough to get rid of the dithering smear on the edges.

I have the 0.75 Starizona SCT reducer/flattener that I want to put into service on my older C8. What back focus is needed with this combo. Note that I have a ZWO 1600MM Pro and ZWO filter wheel as well. I have seen 55mm for this combo - is that what you work with? Also, so you attached the Starizona directly in front of the filter wheel or at the OTA?



#6 Stephanh

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Posted 13 July 2019 - 08:25 PM

I have the 0.75 Starizona SCT reducer/flattener that I want to put into service on my older C8. What back focus is needed with this combo. Note that I have a ZWO 1600MM Pro and ZWO filter wheel as well. I have seen 55mm for this combo - is that what you work with? Also, so you attached the Starizona directly in front of the filter wheel or at the OTA?


The back focus is something like 90mm. I am going by memory here. Asked the folks at starizona to help you out with the gear that you have. They are very helpful when asked questions.
The reducer has to go first in line in the imaging train.


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