I was somewhat surprised to notice that in some places, the audio of the DVD and Laserdisc was radically different. I almost didn't notice the whole thing before the scene where Sinclair tells a guy not to mate with an Arnassian (DVD time code 2:30). The background music's high frequency components (high hats) are a LOT louder in the LD version. The DVD sounds a lot duller. After finding this first difference, it was easy to look for similar scenes, and I found also some other differences. At approx. DVD/18:20 when Londo shouts "Garibaldi!", LD's sound is distorted, but the slightly more muffled-sounding DVD is not. Again, at DVD/19:00, when Londo and Del Varner are discussing, LD has much more high frequencies in the background score. At DVD/24:30, some of Sinclair's lines are looped, and this can easily be heard on the LD. On the DVD, however, the difference is much smaller.
So, what is the real difference between the LD and DVD mixes? Actually, I think that the mixes are the same, and the difference lies in sound handling. The DVD sounds like the audio has been put through an analog noise reduction filter much like Dolby B. (Yes, I do know that the sound comes from a supposedly digital master, but this is how it sounds like.) By this I mean that in the DVD, low-volume high frequencies are attenuated. Which version is in the right then, the LD or the DVD? Without having a definitive reference, I cannot really tell. If asked to make a choice, I'd probably go with the DVD because although it sounds slightly duller, some of the LD problems mentioned earlier are not present with the DVD.
But then to the can of worms, video quality...
Before I go to details, let me remind you of some basic facts about how Babylon 5 was shot and how the special effects were added.
With the exception of the pilot, Babylon 5 was shot in Super-35, a process that has an inherent aspect ratio of approx. 1.65:1 .. 1.70:1. This film material has been read to high-resolution (often also called resolution independent) computer files from where it is easy to convert to any required aspect ratio or video system. The show is shot at standard 24 frames per second and supposedly with an ultimate 16:9 aspect ratio in mind. Although some scenes show great amounts of film grain, everything is fine this far.
But then there are also composite (live action + computer graphics) and CGI (computer graphics) shots. With the exception of the last 5 episodes and some later TV movies, the special effects (SFX) shots have been rendered in NTSC resolution, at 30 frames / second, with an aspect ratio of 4:3. The CGI shots has supposedly been composited in a way that allows for the image to be vertically cropped to get a proper 16:9 version (except The Gathering). This is VERY BAD for a future 16:9 anamorphic presentation. "Why?" you may ask.
If one wants to make a widescreen presentation of Babylon 5 SFX, there are
1) For SciFi Channel, widescreen letterboxed versions of the SFX were prepared. This is a straightforward task: you just put black bars on the top and bottom of the image, and that is that. No resolution conversion is needed. Your vertical resolution for the visible picture area is approximately 360 lines (of NTSC's full 480 lines).
2) For the DVD, an anamorphic 16:9 presentation was made. What this means is that compared to a letterboxed presentation the picture is elongated in the vertical direction until it fits the whole screen. Then the aspect ratio is corrected in the TV (or in the DVD player if you have chosen "4:3 Letterboxed" in its initial menu). If the aspect ratio is corrected in your TV, you get the full NTSC vertical resolution of 480 lines. As 480 lines is more than 360 lines in (1), you should get more resolution, right? Not with Babylon 5.
The problem with anamorphic 16:9 presentation is that Babylon 5's original effects are of NTSC vertical resolution, i.e. 480 lines. To create a 16:9 presentation, you first have to mask 1/4 of these lines, resulting in a resolution of 360 lines. Then these 360 lines have to be elongated to become 480 lines, and here comes the problems. Even at best, video resolution conversion between resolutions close to each other cannot be done perfectly. To make it worse, in this case it looks to me that the conversion has been done in a way that is far from optimal.
To make everything even more complex, I must remind you that NTSC video (just like PAL, for that matter) is interlaced, i.e. only half of the vertical resolution is transferred to the receiver at a time. These half-resolution entities are called video fields, as opposed to frames that consist of two fields. Although I cannot be absolutely sure of this, it seems to me that the conversion from 360 to 480 lines has been done in the field domain and not the proper (and more difficult) frame domain, which means that the end result's resolution is in effect much worse than 360 lines.
Many of the SFX shots are quite fast so this resolution loss cannot easily be seen. However composite shots, like when the Minbari are having a discussion near the beginning of the show, show a decidedly fuzzy and unclear picture, and not all of it can be addressed to blue/green screen problems.
Unless something very dramatic (like re-rendering all SFX) is done, I am afraid that the current 4:3 Laserdiscs will be the definitive edition of Babylon 5 for the time being. This is a sad state of affairs as LDs are no longer available, people don't have LD players, and since only half of the series was ever published on LD.
Although I know this will never happen, I do have a heretic suggestion. It is technically possible to encode all live action in 16:9 anamorphic, and all SFX in their 4:3 form to the anamorphic master. While this would cause all composite and CGI shots to have black bars on the left and right, this wouldn't require vertical resolution conversion which is so destructive to picture quality. Well, as I said, this probably never happens as people generally find changing-aspect-ratio shows distracting.
All in all, NTSC resolution computer graphics, which made it possible to create the greatest space saga of all times within a bugdet, are now the main reason we can't get a proper widescreen release.