June 3rd, 2022, 9:52 p.m. local time

I was fortunate these past two nights to have nearly identical and ideal evening conditions for sky observation, a high rarity.  Last night, the Moon was at 9% illumination, and tonight it was at 15%.

When the Moon's crescent is this thin, it actually becomes difficult to gauge the proper ISO and exposure settings.  At 9% I used 1/8 second exposure in NightCap, and tonight I "halved" that for 1/16 second.  If I had to guess, the Moon's brightness increases nearly exponentially night after night as it approaches Full,; from experience 1/500 may be necessary in just a few days.  If the skies remain as clear as they have been throughout the weekend, we will get to track the nightly reduction in exposure.

Constellation-wise, the Moon is leaving Gemini and entering Leo.

Equipment Used:

  • 127mm Mak-Cass telescope
  • 23mm eyepiece
  • No eyepiece filter
  • iPhone XS
  • Smartphone telescope eyepiece adapter
  • Nightcap app on iPhone
  • f/1.8
  • 1/16 sec exposure
  • ISO 24
  • Focal length: 4mm
  • Minor touchups in PaintShop Pro and AfterShot Pro