Take a look at these two shots....


The light near the bottom is a streak in the one shot, and a point, in the other (a point, for the most part, that is).


These were taken with a 5D Mk 2, 70-200 f/4 IS L, @ f/8, ISO 100. Mirror lock up on both shots.


This image was at 1.6 seconds, EV -0.67. Focal length: 89 mm


[img]/cfs-file.ashx/__key/CommunityServer.Components.UserFiles/00.00.00.25.34/_5F00_MG_5F00_4395ac.jpg[/img]





3 minutes later, this shot was taken. 2.0 seconds, EV 0.67, focal length 78 mm (same settings as above).


[img]/cfs-file.ashx/__key/CommunityServer.Components.UserFiles/00.00.00.25.34/_5F00_MG_5F00_4409ac.jpg[/img]


It was a windy night.


What would cause the light to look like a point source with the longer shutter speed, yet a flare with the shorter?