I just purchased an XSI kit, I haven't actually received it in the mail yet. I have already purchased the 70-300mm IS lens. I'm looking for a minimalist holster for carrying the camera on day trips. I would like to use the Think Tank Digital Holster 10, but I'm not sure it will fit the 70-300mm lens with the extension opened. From measuring the display camera at the local store, and my lens, it appears that my setup will measure out to 8.5" long. The Think Tank Digital Holster 10 shows 8.25" internal length with the extension opened, but the external dimension is 10.25" long. Can anyone tell me if it will fit?