Still want to see stars when taking a picture of the evening sky? So what is the maximum exposure time of your DSLR without seeing tracks of stars on your picture.
Rule of thumb : 600 divided by the focalpoint (mm) x cropfactor DSLR.
Example 1 : Nikon D60 with f 18mm : 600/(18*1.5) = 22s
Example 2 : Nikon D60 with f 200mm : 600/(200*1.5) = 2s
Example 3 : Nikon D60 with Celestron 400 : 600/(550*1.5) = 0,7s
Cropfactor Nikon D60 = 1.5
Text changed on August 5th.
