In article <445991$863@newsbf02.news.aol.com>, online2mch@aol.com says...
>My hand held light meter gives different readings than the through the
>lens meter, even when I move it around the scene. Do I just need to
>experiment a little or is there some trick I dont know about I get >good exposure with th TTL and all batteries are fresh, Has anyone else >had this problem

If you get good exposures with your camera using slide film (negative
films may cover considerable error in your camera meter), calibrate
the hand meter (after setting "0" adjust on it carefully, if there is one) to agree with your camera meter by changing the ASA setting until
the two meters agree, then apply the proportional difference in the settings for different film speeds. When calibrating one meter to the
other, use a 50mm lens on the camera focused at infinity to minimize
errors due to lens transmission and "bellows" factor; use only
neutral-colored subjects (color sensitivity variations in different meter cell types can show apparent differences in light value); use different lighting conditions to see if the meters can be made to agree
over a wide range of light levels (a meter can be non-linear [may read correctly in one light level, but not another] and need either repair
or replacement); use a similar type of hand meter (a "reflected" type, similar to the one in the camera, not an "incident" type [one with a white dome in place in front of the meter cell]); use subjects that are large enough to fit within the metering area of both meters (the camera meter probably reads a much narrower angle than the hand meter); and, finally (whew!), use both meters at the same angle to the subject.
Meter calibration (or, at least, making sure that two meters agree)
ain't easy, but it is worth it to have a reliable back-up and/or separate hand meter.
Hope this helps.