Image size/resolution and textures


I have a question on the size of images I want to use for a texture.
Lets say I have a simple plane and want to use an image of a newspaper as texture for that plane.
My question now is which size (in pixel) of the image is necessary to render that plane with accurate presentation of the newspaper?
The problem is if I have to few pixels within the image, the rendering causes that image to be scaled up and I get a blurred result like scaling up an image in photoshop.
What about the distance of camera to the plane? The closer I come to the plane the bigger the image should be to show clear letters of the newspaper.
If I have to many pixels the image is to big what may results in slow animations.

So the image size depends on the distance of camera to the object and the objects (plane) size itself.
Is there a way to find the best size of an image as texture?

Thanks for any help!

This may not seem very sophisticated, but the way I was told to work it out was as follows.

Firstly, determine how much of the frame the object will fill, at its closest distance to the camera. That number of pixels will be your absolute minimum texture resolution.

For example, the object in question fills half the frame (vertically) at it’s closest. If your render resolution is PAL (720x576), then your texture also needs to be at least half of that.
So, the vertical size of this texture would need to be at least 288 pixels. Of course, this is only a minimum, and I like to give extra just in case, maybe double.

Ultimately you should test with checkered maps of various sizes first, to see what size suits your render settings best.

Hope this helps.

Thanks seabee, good idea!

That number of pixels will be your absolute minimum texture resolution.

double that

Gah, sorry - wrong topic >_<