22.11.2020

 *

Sunday 22nd 48/45F. Clear and bright start but became cloudy with a shower the moment I was set up!

I set the dew bands on half way and No2 reached 79F. No2 reached 75F. The objective is showing a central, 3" diameter dew spot. That explains the very poor images.

11.07 Cloud cleared to remain very milky around the low sun. Still very poor transparency. Sun's altitude only 13°!  The processed H-a image looks more like white light! 

One problem with the D-ERF is that it blocks the sun's heat which might aid dew clearance. There is poor contact with the objective cell because of the D-ERF cell. Which has three huge tightening knobs. The dew band would probably need to be lashed into place to maintain contact with the objective cell.

11.35 A blast of the hair drier helped to clear the misty spot. I have to be careful not to expose the optics to unfiltered sunlight. The later filters help but are not a D-ERF. Still no improvement in image quality. 

I could make a soft muff to go around the D-ERF and objective cell. By enclosing the dew bands it would help to contain the heat and concentrate it where it matters.   

11.41 51/47F There is a dark, petal shaped loop above the spot. I am seeing Newton's Rings on this cropped and enlarged image.

11.50 Still a small spot of mist on the objective. I tried the 2x Orion Shorty Barlow instead of the GPCs. The magnification shot up! The GPCs are intended for the nose of a binoviewer. So the powers quoted 1.6x, 2x and 2.6x are strictly for that position. On the snout of the ZWO camera they are absolute weaklings! Unfortunately the seeing won't support the 2x Barlow. It is a fuzzy mess! 
 

12.00 Swapped back to the 2.6x GPC and spotted a spot on the SE limb. Awful seeing but umbra and penumbra visible!

12.37 53/47F Become very windy. Cropped and enlarged. 2x GPC.

The seeing is boiling furiously now after a steadier morning.

 

 

*