Still Testing New Camera

Using a 3X Barlow Lens

May 23rd was the last mild observing day before scorching, humid, summer conditions began. It was 65 dry degrees with a light breeze. The Sun was very quiet with only a few small sunspots, but the excellent, comfortable conditions made getting familiar with my new camera enjoyable.

On this day I used a tilt adjuster between the camera and telescope to attempt removal of annoying dark interference fringes which appeared on previous images taken with a 3X Barlow lens. The very first video showed stray light leaking onto the camera chip from an uncovered gap in the tilt adjuster. I fixed this with black electrical tape. Since the interference fringes are not visible in the live laptop screen preview, I processed the first videos immediately to see if the fringes were removed by the tilt adjuster. I didn't see any fringes in the individual images, so I thought the tilt adjuster had worked. I then proceeded to record videos for a mosaic of the entire Sun. Eventually I constructed the 17-image imperfect mosaic shown in the first picture below.

The mosaic shows lots of prominences and filaments, but few sunspots. I like the resolution of details with the 3X Barlow. (Click on the image for a larger view.) Unfortunately, the tilt adjuster did not entirely remove the vertical interference fringes. They became more subtle, but they are still present as you can see on the image below. This is disappointing because they ruin an otherwise nice picture.

The inverted disc image looked fairly nice with the fringes barely apparent.

No fringes are visible in this image of the prominences alone:

Next is a 3-image mosaic of a particular region entirely within the solar disc. The picture has been processed to increase the visibility and contrast of features. (Click on the image for a larger view.) . The fringes are barely visible and detail is quite good.

Lots of trial and error remain before operation of my new camera becomes routine. Perhaps I can remove the interference fringes with a flat field. I'll try this next.