Originally posted by polur101 I have been using K20D, Pentax lens SMC DA 18-250 as a general purpose lens, AF540FGZ flash for over 2 years with no problems. I also have a K200D (I like AA battery capability). Over the last few days, the K20D's behavior has been bizarre. When I use the external flash, the exposure varies from total bleach to total darkness. Typical settings are: Program mode, usually f4 to f8, depending on ambient light. Shutter range 60 to 180, ISO range 100 to 800. I usually leave ISO on auto and let the camera pick. Until 2 days ago, shots were on the mark with no exposure compensation. The same flash gun on my K200D is on the dot. What's more bizarre, is that the built in flash on K20d gives accurate result and as well when I use the 540fgz in wireless mode as primary with internal only as a control, I get good result. Any ideas?
kris.
Try re-registering the flash on the K20d. Make sure you are using the right channels, and so forth, as in your manual. It sounds as if the flash might be on a different channel than on the K20d - you might have accidentally changed it when registering the K200d.