A question for all of you long exposure and night shooters. I shot a 30" exposure last August that I'd like to replicate with the same look, from the same spot with the same exposure data. I checked the Photographer's Ephemeris for the time of sunset for both last August's date and today. If my shot last August was at 23 minutes after sunset, will the sky be the same level of darkness tonight at 23 minutes after sunset (assuming the same or similar cloud cover), or will my exposure be different tonight because it is now nearly winter? Moonlight was not a factor last August, nor should it be tonight. Is there another mitigating factor that for which I need to account?
Thanks in advance.