Can someone who knows more about rangefinders than me tell me what the deal is with the M7 rangefinder patch? Is there some trick to getting it the rectangular white focusing patch very visible? Sometimes it is fainter than others, and sometimes it is not there at all. I think maybe I'm holding the camera incorrectly and just need to be schooled better on rangefinders (lifelong SLR person). Or does it have to do with the quality of light hitting the camera? I'm aware of the viewfinder upgrade (MP version) available for the M7. Will this help my problem? I really don't feel like spending $300 for the upgrade, so any advice will be greatly appreciated. Thanks very much.