"Does it really matter if the math is that of true lenses? Is not the purpose of Vue to simulate reality, rather than to recreate it? In other words, if it looks enough like photographic lenses is that not sufficient, no matter the method? I haven't explored the Vue perspective/aspect ratio render stuff though". hehe. Remember, under the hood, Vue is doing exactly the same as any other 3D app. View transform is pretty standard and there's only one way to transform 3D into 2D (unless you're using After Effects and god only knows what's going on there). So, it's doing it right, it's just being a bit selective about what it exposes to you. Does it matter? Depends. For most users probably not. But if you want to match to live action or another app then yes, it does because you're probably going to be dealing with FOV, not focal length. For example, my XSI camera I'm using a 34mm focal length but I'm using PAL as the image format. If I decide to work in another format then I need to adjust my focal lenght accordingly. Note, this isn't a limitation of XSI, this is the way real world lenses work, so it's not behaving like real world cameras at all. I'm being picky right now because I do have to match XSI moves back into Vue. I'm also working with kind of an odd aspect ration; 4.4:1, so I'm going to be a bit touchy until I know it works. If it doesn't, expect me to come back and scream a bit more ;-) For most people using this software, it's not an issue but that's not really my point I was trying to make. What I was trying to say is, it's wrong and in my experience, you don't do it properly it comes back and bites you in the ass. I come from a background of film and photography and I've done a lot of movie work, matching CG into live action and vice versa. I like to see things done properly and it bothers me when it's not, because that's when things go wrong. sorry for boring everyone. I'll go back to my box now. see www.cg-soup.com for some of the stuff we do.