Does anyone have an experience, info or manuals for the Yashica MF-1? I got one that winds, fires, the meter works and the flash works. I'm shooting my first roll now. My issue is that the shutter won't fire in anything less than daylight. I thought this camera would expose for as long as 30 seconds. The shutter button actually locks (won't depress all the way) in darker conditions. The ASA setting works, because the amount of light required does vary appropriately as the ASA changes from 25 to 500. It's acting kind of like "shutter priority", where the shutter stays at what sounds like 1/60, and the aperture varies with the light levels. Any ideas?