I have two 20" widescreen monitors and the aquarium does not pan. I thought this was it's maximum width!
This gets difficult to judge because of the vast differences in displays, both in their aspect ratios and possible multi-monitor configurations. To further complicate matters, MA3 auto adjusts itself to some degree. After doing some experimentation, I came up with the following procedure to figure out whether MA3 should, or should not pan on multi-monitor displays:
1) find the resolution of each monitor in use and jot them down.
2) add up all of the horizontal resolutions for the widest part of the overall display. For example:
a) 2 monitors side by side at 1024x768 = 2048
b) 3 monitors side by side, 2 at 1024x768 and one at 1680x1050 = 3728
c) 4 monitors, 3 side by side at 1024x768 and one above the center monitor at 1024x768 = 3072 (3 times 1024 for the 3 side by side monitors which comprise the widest part of the display)
3) repeat step 2 above for the vertical resolutions.
4) divide the maximum horizontal resolution found in step 2 by the maximum vertical resolution found in step 3. The resulting number is the aspect ratio of your entire display (i.e. x.xx:1). For example, here are the aspect ratios for the examples cited in step 2 above:
a) 2 monitor setup: 2048x768 = 2.66:1 aspect ratio
b) 3 monitor setup: 3728x1050 = 3.55:1 aspect ratio
c) 4 monitor setup: 3072x1536 = 2:1 aspect ratio
As far as I can tell, for aspect ratios of 3.15:1 or lower (i.e. 3.0:1, 2.8:1, etc), MA3 will pan. The smaller the first number, the more panning there will be.
For aspect ratios between 3.2:1 and 4.2:1, MA3 will display quite well without panning. It does so by cutting off the upper and lower parts of the overall scene to auto-adjust itself. Aspect ratios of up to 4.2:1 maintain all of the coral formations and the almost all of the top layer of gravel within the visible scene.
Aspect ratios greater than 4.2:1 continue to try to auto-adjust by cutting off more and more of the top and bottom of the scene, but it really begins to detract from the overall scene due to parts of the coral, clams, etc. disappearing.