Lazy load not sensitive enough?

First of all, great plugin that works extremely well. I use it very often on almost every single website I build.

Only problem I have is with the lazy loading feature – it seems kinda slow. The images only load at the last, last second, so you can still see the images flash when they load. Is there a PHP filter I can use to adjust the sensitivity of the lazy load script so as to make it load the images a couple hundred pixels before they actually get to the image?