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150p Quattro bad vignietting

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Hi All,

i just got the 150p Quattro for christmas, but i had bad weather and could not use the scope. today i got 30 minutes of clear skyes and wanted to test the new sope. This is when i saw that i a lot of uneven vignietting with a 1" sensor (ASI533MC). I took some flats and wanted to see if someone can help me solve this isue. Also if i change the frame the vignietting also changes.

some more details, backspacing is ok and the coma corrector comes with the scope, i also colimated the scope so i think the only thing to mess around with is the focuser. But before i do that, i wanted to see what more experience people have to say.

Attached are two flats for reference.


Thank You and Clear Skies!

Bad Flat 1.jpg

Bad Flat 2.jpg

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If your secondary is concentric and collimation is good, but you see the vignette move around when you move the focuser and camera together, you might have a sag or tilt in your focuser drawtube and the sensor is not parallel to the long secondary-to-primary optical axis of the OTA. It could happen also if your secondary is not perfectly concentric and centered with the optical and mechanical axis of the focuser, where the secondary is positioned a little too far down or up the tube. Less likely if your collimation is good. worth checking, just in case any focuser sag was already existing when you collimated.


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managed to mostly center my secondary mirror, it was out of aligment with the focuser. Not an easy step, but with patience and a sight tube i managed to get it almost centered :)

here are some images taken with the scople (it was just a test run so no darks or biases, only flats and onle 10/5 minutes of data)

Thank You and clear Skies!

Hercules Cluster_SiriL_Ps.jpg

Final_SiriL_Ps v1.jpg


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