The Conditions window allows you to enter the sky conditions at your time and place of observing. Conditions are used by Deep-Sky Planner Mobile Edition to predict an object's visibility. Sky conditions are presented in collapsible panels for each type of condition. Tap the down arrow at the right of the panel to expand its contents or the up arrow to collapse its contents.

Note: In the description of a range of values, an endpoint is inclusive of the value if a square bracket is used. An endpoint is exclusive of the value if a parenthesis is used. For example, the range (0.4, 1.0] means greater than 0.4 and less than or equal to 1.0.


MPSAS allows you to enter a darkness measurement in magnitudes per square arcsecond. This is available from a Sky Quality Meter (or similar). As you enter the MPSAS value, the corresponding naked-eye limiting magnitude value is calculated and shown in NELM. Also, the darkness zone color is shown for the MPSAS value as used in "The New World Atlas of Artificial Sky Brightness" (Falchi et al, 2016).


You may choose the relative transparency value that best describes your sky. These values correspond to ranges of Aerosol Optical Depth (AOD) values in order to better quantify your conditions.

Value AOD
Perfect [0.0, 0.1)
Clear [0.1, 0.2)
Slightly Hazy [0.2, 0.3)
Hazy [0.3, 0.4)
Very Hazy [0.4, 0.5)
Extremely Hazy [0.5, +)


You may choose a relative seeing value that best describes your sky. The values correspond to the indicated value or range of values in the Antoniadi or Pickering scales, or the minimum visual angular separation of stars in arcseconds.

Value Antoniadi Scale Pickering Scale Separation
Perfect I 10 [0, 0.4"]
Good II 8-9 (0.4", 1.0"]
Moderate III 6-7 (1.0", 2.5"]
Poor IV 4-5 (2.5", 4.0"]
Very Bad V 1-3 (4.0", +)

Help file version 1.0.117 ▪ Copyright © 2021 Knightware, LLC