Tools

Pixel Scale vs Seeing

What This Calculator Tells You

Match your imaging setup to your local seeing conditions. This calculator shows whether your current configuration is optimal and suggests adjustments to get the best results from your equipment and sky.

Assumes seeing-limited imaging. Guiding accuracy, optical quality, and focus may further constrain usable focal length.

Your Setup

0.78"
Image Scale
3.2x
Sampling Factor
Good
Match Quality

Configuration Options

ConfigurationEff. FLScaleFactorMatch
Native1000mm0.78"3.2xGood
With 0.67x Reducer670mm1.16"2.2xGood
With 0.8x Reducer800mm0.97"2.6xGood
With 2x Barlow2000mm0.39"6.4xOver
With 3x Barlow3000mm0.26"9.7xOver

Your Setup is Optimized For:

1.6" - 3.1"

seeing conditions

For 2.5" Seeing, Ideal FL:

620 - 1241mm

with your 3.76μm pixels

Matching Strategy

  • Good seeing nights (1-2"): Use longer focal length or barlow for higher resolution imaging
  • Average seeing (2-3"): Native focal length usually works well
  • Poor seeing nights (3"+): Use focal reducer for wider field; don't waste effort on high resolution
  • Be flexible: Having both a reducer and barlow lets you adapt to conditions

Quick Reference: Seeing Conditions

SeeingConditionsBest Targets
<1.5"ExcellentPlanets, small galaxies, planetary nebulae
1.5-2.5"GoodMost deep sky, galaxy details
2.5-3.5"AverageLarge nebulae, wide field
>3.5"PoorWide field mosaics, large targets only

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