Where I go for Astrophotography


I photograph from my back yard 28 miles south of Washington D.C. and from a farm 7 miles south southeast of Blueknob State Park, PA.
My back yard is located 9 miles north northeast of the Stafford, VA clear sky map center.
The farm is located 18 mikes south southwest of the Altoona, PA clear sky map center.
The scale on the Stafford clear sky map measures 180 miles wide by 240 miles high, even though the image appears square.
These map locations place the farm in a yellow colored region and my backyard in an orange colored region.
The yellow region is defined as Bortle scale 4.5, (Some dark lanes in milkyway but no bulge into Ophiuchus. Washed out milkyway visible near horizon. Zodiacal light very rare. Light domes up to 45 degrees. Limiting magnitude about 5.9 to 6.2.).
The orange region is defined as Bortle scale 5, (Milkyway washed out at zenith and invisible at horizon. Many light domes. Clouds are brighter than sky. M31 easily visible. Limiting magnitude about 5.6 to 5.9.)
Despite the clear sky map I believe the farm is a Bortle scale 4 because the Milky Way does show a lot of dark lane structure.