Maxwell Everett wrote:
I thought that was odd too. There appears to be too much directional blur on the deflector and windows. But also, the lighting is noticeably different between them. In the original SD version, look closely at the shadow being cast by the left nacelle onto the support strut beneath it. Now, look at the HD version... no shadow. The backlight is lower. There are other lighting inconsistencies as well. The angle is also subtly different -- the camera is ever so slightly lower in the HD version. This appears to be an alternate VFX take. I guess they weren't able to find the original shot..
For a number of the ship fly-by shots (especially in Seasons 4 and 5), they were missing elements. Where possible they've used alternate takes which match the original closely or CG substitution if necessary.