I am very new to photography. I have a Vivitar 45 light meter. From what I have read on this site and other information sources, I have some understanding. My understanding is that you: (a) Set the ASA for the film you are using (b) Hold the meter at the subject and point toward the camera (c) Pull back on the meter switch (d) Rotate the large dial until the two hands are aligned After this,I have an EV number, and a list of corresponding shutter speeds and f stops. What I don't understand is, if I know the f stop and shutter speed, what does the EV number tell and why do I need to know what the EV number is? Also, The front of the meter has an opening that you can slide a white cover over. Am I correct that you use the white cover for metering when not using a flash and if using a flash you slide the white cover off of the opening? One last thing, is there a site I could go to get a manual for this meter?