Planetarium software (what gives ?)

[kolyma]

The image at top left is a capture from a video shot at dawn off the cost of Galicia in sep 2009 showing the eastern horizon and posted on youtube. From the positioning of the moon and Venus I determined it was the morning of sep 17. I got the three other images from planetarium softwares for 17/09/2009.

Can you explain the difference in positioning between the first and the other three ? Thanks.

[Freddie]

What did you use to decide it was 17th Sept? Maybe that was wrong? Three Vs one would say it was.

[kolyma]

The video was posted online on sep. 29 2009 and was filmed that year. The venus over the moon alignment of sep 17 is the closest, for 2009, to the one seen in the video.

[Freddie]

You haven't said what you used to determine that date. Those 3 bits of software would indicate that you got your date wrong. Why not go out and determine if they are accurate by doing your own observation? I think you will find that they are accurate.

[Daggerstab]

Combination of different projection settings and FOV values? (Stellarium by default uses stereographic projection, most camera lenses produce rectilinear pictures.)

Another possibility is time zone and DST differences - most amateur-level astronomy software doesn't handle them well.