This may not belong here, but I’ll try it anyhow.
The new particle system for hair is great, but there’s something about it I don’t really like. Take a look at the image below:
The blue lines are particles while the red lines are planes. Planes scale correctly for the perspective while the particles remain unchanged.
I feel the particle widths should be perspective correct. This will only involve scaling the width of the particle (such as how the material thinkness setting) by the correct size for the perspective of that position in space.
Also, the size of the final render image should be taken into consideration while calculating the scale size. Otherwise, high resolution final renders would have much thinner strands than lower resolution test renders.
I ran into the problem while trying to see what particle grass might look like. The strands near the camera were too thin, and the strands way off on distant hills were much too fat.