The Canon external light meter is a high-quality accessory designed specifically for Canon P, VI-L, VI-T Rangefinder RF Cameras Its snap-on mount allows for easy attachment onto the speed selector of Canon P, VI-L, VI-T Rangefinder RF Cameras This external light meter from Canon is a reliable tool for ensuring optimal lighting conditions when shooting with Canon Rangefinder film cameras. This has not been tested on a camera using a film to check results, however the meter needle does move and seems to correspond with variation of light Also looks to be missing a small part off the back
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