The graphics are a rabbit hole you can disappear into for days on end, and still be stuck on the queen's chess board as a pawn... However, you would have to divulge which video card you have for someone to be able to help with possible improvements there.
In the meantime, be certain you have your video "stream" set correctly. The 'modern' LCD vid display has a "native" resolution. If you look in the Windows dialog for the desktop Resolution, it will be listed as "(recommended)" next to the actual resolution numbers. Set the Windows properties to that. Then, in the game's Options menu, Graphic Settings section, use the drop down box to also choose that resolution. You might have to scroll through the list to find it, since the game is basically ignorant of a lot of the available resolutions and defaults to using 1024x768, so you'll have to choose proper settings yourself. btw - Do not use the v-sync setting in the game's Graphic Settings page, else you increase the odds of encountering "jello water". Also do not use "Volumetric Fog" on the same menu because the Deck Watch will turn into ghosts on you. "Environmental Effects" can cause similar issues on some systems... "Light Shafts" when you are underwater are really cool, but even the "Post-Process Filters" can cause things to glow at night in the game, but it does add to the depth of color, making the game look somewhat like a Technicolor movie, film grain and all.
Before you get into that though, make certain you have your game installed correctly and the mod activated properly. There is detailed information for installation in the mod's Support folder in "Install Notes For SH4.pdf", and activation in the "Activating Fall of the Rising Sun Ultimate Edition.pdf". Warning: Verbosity reigns supreme in those files... In a nutshell, you want your installation to not be in a "Program Files" folder, but rather in a folder you create yourself, such as "C:\MyGames \SH4" or whatever. If you have Steam, things might get complicated in that regard, but it is possible. Consult
Moving a Steam Installation and Games in the Steam Knowledge Base. Not knowing your particular version of the game, whether disk or software, etc., we'll wait until you reply. Also, you MUST use v1.5 of SH4 (aka: Gold aka: U-Boat Missions Add-On). The game will throw errors if you activate the mod on v1.4 or earlier versions.
Let us know which SH4 you have, and where you have it installed.
