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M13--which scope


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I am in a quandary.  Takahashi has come out with a new flatner that has spots of 1 um on axis and 2 um at 30 mm.  that is better than the current flatner that I am using.  I am trying to decide if an upgrade is worth it.  Its for the TOA 130, which means shooting at a resolution of .78 arcsec (well, maybe a bit more becuase the flatner is .99x).  However, .78 is awful high resolution for a 5" scope and poor seeing--it is, coincidentally, the same resolution as the C11Edge with .7x reducer binned 2x2.  Which of these setups is better.  Hard to say, as the C11Edge is much better for small galaxies--but that might be an illusion due to FOV.  Crop the TOA image to the same dimension and its a different decision.  In a good sky, no doubt the C11Edge will win becuase the target will be registered on more pixels--hence more and deeper target.  However, this is only true when seeing allows the resolution.  The other advantage of the TOA is binned 2x2 it is 1.46", which is just about perfect (in case anyone is wondering, the reducer (.7x) yields a resolution of 1.12", which is still a bit much for my sky.  Binned its 2.24", which is not quite enough).  

Read through it a few times as a stretching excersise as you will no doubt be turned into a pretzle when you are done.  As am I.  Not so much for the technical aspect, but for the fact that I am trying to decide if getting the new flatner is worth it.  Obviously, getting the flatner would mean (should mean) that I use the TOA with flatner more than the TOA with reducer or C11Edge with reducer.   Enough.

Here are two images of M13...one taken with the C11Edge and one taken with the TOA 130.  Both images are shot at about teh same pixel scael (.78 and .80).  The tOA image has been cropped to bring the image scale closer--still not quite the same--that is becuase of the limits iof the image (my processing skill and the sky).  Interestingly, the TOA image has 2x the data as the C11Edge image (8 hours vs 4 hours).  This leads me to the conclusion that at the same pixel sacle with the same camera, aperture equals speed.  This is even more evident when one considers that the C11Image is shot at almost 2x the focal length (1960 vs 1,000).  I included the uncropped TOA 130 image for reference.  These TOA images were shot with the 67 flatner--the old flatner.  How mucg better is the new flatner likley to be?

Questions:  TOA 130 or C11Edge.  If TOA 130, do you think new flatner will show improvements.  The issue is, if I am going to shoot at higher resolution,--should I use the C11Edge and if I am going to shoot at lower resolution, should I use the FSQ 106, which is 1.5 native, with a much wider FOV than the TOA.  

Warning..there is an obvious downside to having multiple scopes.  

TOA 130 Image



C11Edge Image



TOA full image


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45 minutes ago, Rodd said:

Thanks Scott.  


9 minutes ago, glafnazur said:

The TOA image is breathtaking 👍

Yes but the core is not as well defined.  I know they are different animals that produce different images, despite my efforts to equalize them.

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