Hi there! I am looking forward to participating in a meteorology class in about a month that includes 10 days in the field storm chasing. The goal is to capture great weather systems including lightning, cloud formations and tornadoes.

I shoot with an E500 & E520, and have a limited number of lens currently in my bag. The fastest I have is a 14-54 f/2.5-3.6 and the longest I have is a beastly slow 70-300 f/4.6-5.6. I'm feeling the need to have a better, faster lens for what I believe will be photography at a distance and possibly/probably in low light conditions. I will travel with both bodies but anticipating doing most of my shooting with the E520 due to the IS feature.

I am experienced in shooting the aurora borealis and using manual, long exposure settings on a tripod so that isn't too worrisome for me. What I'm in need of is some advice as to what lens I should be using for the type of experiences I'm anticipating. I won't be purchasing, but rather, renting from an online vendor. Any advice is welcomed!

Thanks much,