21.08.2022 Lunt 60MT etalon imaging trials.

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Sunday 21st 65-70F, sunny all morning. Cloudy and windy in the afternoon.

 Following on from yesterday's struggle with uneven image brightness: I am continuing to experiment with focus and etalon tuning settings.  

 I have inserted the 2.6x GPC in the camera nosepiece to narrow the field of view. Even then I had to heavily crop the image. Just to remove off band brightness at the edges of the image.

10.4.  I repeatedly readjusted the tuning and focus. The image field is much more even in brightness and detail. I am using the 912x912 frame size as usual.

 

 

 

 

 11.00 More even brightness but [dare I say it]  rather boring! (?)

 

 

 

 

 

 

 

 11.30  Strange AR on the eastern limb. I have yet to confirm the correct orientation of the sun's image. [After fitting the diagonal.] I need an image with a clear, dominant feature.

 

 

 

 

 

 

11.50 First attempt at capturing proms with the new etalon. I made NO attempt to retune for the proms. A GPC would have been a good idea to increase the image scale. I had to heavily crop the image to make them visible.

 

 

 

 

 

 

12.02 Fitted the 2x GPC to the camera nose for more scale. Retuned the Lunt 60MT etalon for the darkest and most even brightness. Much more sense of surface relief. Perhaps a bit over-sharpened. Though I think I am finally beginning to get somewhere.

 There is still some increased brightness from the left [eastern] side. Which could easily be cropped out. I will keep trying.

 The 2x GPC seems to provide the optimum evenness of brightness. The 1.6x GPC retains the ring-shaped, sweet spot.

 

 

12.36 2x GPC.

It is becoming too windy to continue. The telescope is being blown about. Pause for lunch.

 

 

 

 

 

 

PLEASE IGNORE ANY MENTION OR ILLUSTRATIONS OF MY MOUNTING THE ETALON DIRECTLY TO A STAR DIAGONAL! IT WAS A BAD IDEA!

THERE IS A VERY REAL RISK OF ROTATION: OF THE HEAVY ETALON-FILTER ASSEMBLY AROUND THE FOCUSER AXIS!

POTENTIALLY LEADING TO CATASTROPHIC DESTRUCTION OF THE ETALON, FILTER ASSEMBLY AND THE CAMERA! PERHAPS THE ENTIRE TELESCOPE ITSELF! EVEN THE MOUNTING COULD SUFFER SEVERE DAMAGE!

DO NOT TRY THIS AT HOME!

YOU HAVE BEEN WARNED!!

I CANNOT BE HELD RESPONSIBLE FOR ANY CONSTRUCTION OVER WHICH I HAD NO DIRECT SUPERVISION!

 

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