Dark sky on Sunday: three focal lengths

 I was so excited by last-night's results that I posted them first.  However, the previous night (Sunday, 10 May) was almost as dark.  On Sunday I measured sqml=21.78 mpsas directly overhead.  The linear brightness ratio between 21.84 and 21.78 is 1.06.  Less than ten-percent differences are generally below the level of perception.

On Sunday I used three lenses:  Rokinon 7.5mm f/3.5 fisheye, Leica 25mm f/1.7, and the Olympus 75mm f/1.7.

 

Venus setting over Bristol Head.  Rokinon 7.5mm fisheye.

Jupiter setting over Bristol Head. Rokinon 7.5mm fisheye.

In the above image I applied a 3x3 Median filter to suppress the myriad of faint stars and emphasize the sky-brightness gradations caused by airglow and Zodiacal Light.  A faint arc of Zodiacal Light stretches up to the left from Jupiter in the lower middle of the frame.

Looking north.  Rokinon 7.5mm fisheye.

 In this image, the Big Dipper is in the middle of the frame.  An arc of Zodical Light curves up along the left edge.  In the bottom right corner the northern Milky Way is emerging above the NE horizon.  A median filter was also applied to this image.

Melotte 111. Leica 25mm f/1.7 + softon filter.

 The star cluster known as Melotte 111 (Mel 111) is the centerpiece of the constellation Coma Berenices.  The cluster was almost directly overhead.

Omega Centauri. Olympus 75mm.

 The giant globular cluster Omega Centauri clears the distant summit of Piedra Peak by only 1.8 deg.