Which Eva series is this? If it is the US Manga Ent. D&R or EoE DVDs then you might be noticing the widescreen letterboxing used on the release. If you have the Japanese R2 Movie DVDs, then they are anamorphic 16:9 like the Karas DVDs and the Fullmetal Alchemist Movie DVD (which aren't out yet).
If this is the NGE TV series you are using then there should be no problems since it is also 4:3 like the Fullmetal Alchemist TV series. Well, then you would have problems with the Karas footage since it is supposed to be 16:9 anamorphic widescreen.
I'll need a full list of your sources to properly give you advice on how to fix your problem. Here are the possible sources from the available R1 DVDs:
Neon Genesis Evangelion TV series (ADV): 4:3
Neon Genesis Evangelion: Death and Rebirth (Manga Ent.): 16:9 letterbox widescreen
Neon Genesis Evangelion: End of Evangelion (Manga Ent.): 16:9 letterbox widescreen
Fullmetal Alchemist TV series (Funimation): 4:3
Karas OAV series (Manga Ent.): 16:9 anamorphic widescreen
Japanese R2 DVDs (if different):
Neon Genesis Evangelion: Movies (Japan R2): 16:9 anamorphic widescreen
Fullmetal Alchemist: Shanbara wo Iku Mono (Japan R2): 16:9 anamorphic widescreen
(If you need an explanation of some of these terms, click
here for letterboxing,
here for anamorphic widescreen, and
here for a detailed technical explanation of how to identify widescreen footage and
how to handle widescreen footage when using DVDs.)
Crash course in Aspect Ratios 101
I'm going to make an assumption that you are using the Eva movies as footage since the TV series wouldn't look "smaller" compared to the rest. Now, the question I have to ask, is this video going to be widescreen (16:9) or standard (4:3)?
This is important because since you are using Karas as a source, assuming that this is from the R1 DVDs, it is 16:9 anamorphic widescreen footage and to make it look correct in a standard 4:3 aspect ratio video will entail cropping (cutting the sides off to make it 4:3) or letterboxing it (adding black bars to the top and bottom to make it 4:3). Also, the Eva movies are 16:9 letterboxed widescreen so technically it is 4:3 and you can leave it alone, but if you want to get rid of the letterboxes (the black bars), you will also need to crop the video (top and bottom to lose the LBs and the sides to make it 4:3, and its gonna make it look somewhat crappy after resizing). The Fullmetal Alchemist footage then will look a bit out of place because it will be fullscreen.
If you decide to make it 16:9 widescreen, the Karas footage is OK. The Eva footage will need to be trimmed of the letterboxes (crop top and bottom about 60 pixels each, then resized) and the Fullmetal Alchemist footage is also gonna have to lose some of the image top and bottom to make it 16:9 without stretching the image (same amount as the Eva footage, then resized).
You are now asking why do I have to do all of this, isn't all the footage the same resolution of 720 x 480? Yes, but now this part is pretty important, 720 x 480 is not 4:3 aspect ratio nor is it 16:9 aspect ratio. Correct 4:3 video is 640 x 480 and correct 16:9 is 848 x 480. The explanation is
very technical, and it can get
even more technical.
I'll leave you with a link with some pics showing why you'll probably need to resize footage to 640 x 480 or something similar:
http://www.animemusicvideos.org/phpBB/v ... hp?t=65156
I'm working on a Mini Illustrated Guide to Aspect Ratios to reference until EADFAG or whatever it eventually gets called is updated.