I love to use a vertical grip. This is a tool the BG-E2N you should have on your Canon EOS 50D. The grip is also revers complatible with the EOS 40D, 30D and 20D. Having two Canon BP-511 batteries in the grip allows over 1000 shots before a recharge is necessary. Additionally, the grip includes a AA battery tray that will allow you to use AA batteries in lieu of the BP-511′s. However, this is an “Emergency Use Only” type of accessory, as your battery life will be significantly reduced. I carry it in my bag in the VERY unlikely event that I manage to drain both of my BP-511′s. You can find AA’s anywhere.