Quote - Okay, thanks for the feedback.

When you render larger and then reduce down in post production, is there any degradation of the image?

What most rendering software does when antialiasing, is in fact a process that simulates the effect of resampling, that is: interpolation.

Rendering software does that taking into account several aspects of the image, such as the contrast, edges, et c. - but what it does, it must do starting from the final image size, and ending up with the same final image size.

The advantage of doing the interpolation starting from a rendered image that is 4 times larger than the final size, is that the interpolating software (Photoshop, or PSP, or whatever you use) has 4 times more the resolution and data to work on. The advantage of doing the interpolation on an amount of pixel resolution that is 4 times larger, is immediately understandeable

The correct way of doing the resize is to do it only once. It is obvious that the more you process an image, the more you get distant from the original data. if you process the image just once in Photoshop, you'll end up with a very good final result. The rendering software itself, when antialiasing, processes the image, but it does starting from a smaller resolution.

In Photoshop CS2, I use the "bicubic sharper" as resampling (=interpolating) method. I choose it because it gives back some of the finer details that are usually lost when interpolating or antialiasing. This also saves from the necessity of performing an extra sharpening process - which would add another processing step to the final image.

Interpolation plugins such as Fred Miranda's or Genuine Fractals can do an even better job - but they're not freeware. You don't have to spend necessarily much money anyway - there is software that is free or almost, and offers decent interpolation algorhythms such as Lanczos. You have to experiment and find out the solution that you like better, and adapts better to your requirements. Just keep in mind this - process the image only once - and you'll be safe, quality-wise.