Hi Boris, Most likely the lens with the adapter in not shorting the contacts on the lens mount of your ZX-L. If these contacts are not shorted as with a "K" mount lens, the camera does not realize a lens is attached and will not provide focus confirmation. Also, many screw mount lenses have the mount area painted, which will not short the contacts even if contact is made. A couple of solutions are to scrape away some of the paint, or gluing aluminum foil to that area on the lens.
Hope this helps, William in Utah. ----- Original Message ----- From: "Boris Liberman" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Thursday, July 17, 2003 12:56 AM Subject: On Effective Aperture > Hi! > > I am still struggling with the choice that I have. Should I buy the > Vivitar M42 100-300/5 that is coupled with special doubler that would > give me something like 200-600/8 or so?! > > Anyway, today I tried to mount it (without the doubler) on my ZX-L and > observed the following strange thing - the auto focus wouldn't confirm > state of focus (for 300 mm wide open). Of course f/5 is not the > brightest of apertures, but still, the darn body does bring to focus > Sigma 28-135/3.8-5.6 on the long end. And there the aperture is even > narrower. > > So here is my confusion - > 1. Does it mean that Vivitar has narrower actual aperture? Or probably > Vivitar is too soft for the sensor to discover the contrast? > 2. Does it mean Sigma has wider actual aperture on the long end? > 3. Does it mean that aperture numbers of the lens are more of a > guideline and less of a precise technical data? > > Ultimately, I think I will have to pass on that zoom lens though I > really like to be able to go as far as 600 mm of focal length. I can > focus it well with my ME Super but I wanted all my lenses to be > useable on all my bodies. It would not seem to be true for this lens > and ZX-L. > > Cheers! > > Boris > >
