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IDProjectCategoryView StatusLast Update
0002158CCdcielGeneralpublic19-07-26 17:14
Reporterhan Assigned ToPatrick Chevalley  
PrioritynormalSeverityfeatureReproducibilityhave not tried
Status resolvedResolutionfixed 
Target Version1.0 
Summary0002158: Improved accuracy for dynamic focussing with a change in pu_hyperbola.pas
DescriptionAfter some new analyses. I noted that the bottom of the hyperbola is below the real focus V-curve. This is because of the seeing. To improve the curve fitting, the bottom of the hyperbola is clamped against the lowest measured HFD.

The measured V-curve wings are more parallel to the hyperbola. So I expect the hyperbola bottom (=vertex) is better indicating the best expected focus. Below the curves with real data from last night and using automatic curve fitting. Left images are the old setup. Right images are the new setup. Look to the wings:
Steps To ReproduceUse attached improved unit pu_hyperbola.pas
TagsNo tags attached.



19-07-26 00:06

reporter (2,581 bytes)
test near zenith.png (44,662 bytes)   
test near zenith.png (44,662 bytes)   
test near M20.png (39,739 bytes)   
test near M20.png (39,739 bytes)   


19-07-26 00:11

reporter   ~0005792

This image described the effect better. The hyperbola is limited to the thick line called "seeing limit" making a better fit possible.
happylimpet2.png (29,627 bytes)   
happylimpet2.png (29,627 bytes)   

Patrick Chevalley

19-07-26 15:01

administrator   ~0005793

Yes this look a good improvement.

I commit your change:

I like your graph with both the measured and computed curve. I will try to improve the graph in CCDciel to do the same and maybe zoom it in a larger window if double clicked. This can help to estimate the focus quality .

Patrick Chevalley

19-07-26 17:14

administrator   ~0005794

I do this change to the autofocus graph, a double click open the graph in a new window as in the screenshot done with the Indi simulator.
focus_graph.png (13,373 bytes)   
focus_graph.png (13,373 bytes)   

Issue History

Date Modified Username Field Change
19-07-26 00:06 han New Issue
19-07-26 00:06 han File Added:
19-07-26 00:06 han File Added: test near zenith.png
19-07-26 00:06 han File Added: test near M20.png
19-07-26 00:11 han File Added: happylimpet2.png
19-07-26 00:11 han Note Added: 0005792
19-07-26 15:01 Patrick Chevalley Assigned To => Patrick Chevalley
19-07-26 15:01 Patrick Chevalley Status new => resolved
19-07-26 15:01 Patrick Chevalley Resolution open => fixed
19-07-26 15:01 Patrick Chevalley Target Version => 1.0
19-07-26 15:01 Patrick Chevalley Note Added: 0005793
19-07-26 17:14 Patrick Chevalley File Added: focus_graph.png
19-07-26 17:14 Patrick Chevalley Note Added: 0005794