Recently bought a Metz 54 MZ 4i to use on my Pentax K20.
Even though I set camera and flash on TTL, it fires all right but does not give me proper exposures.
Helpful hints anyone ?

Thank you.

Joe

[Canada_Rockies]

The K-20 does not support TTL, just P-TTL. Some of the Metz flashes can have the module upgraded. Check in the accessories forum. Meanwhile, use the Auto feature on your flash that uses the flash's sensor.

[SOldBear]

What is the model of the SCA module?

The only module that supports p-TTL is the current version SCA3702-M3; but wireless, and high-speed sync are not supported. SCA3702-M2 can be updated (no charge, at least a year ago) to M3 by Metz service center. SCA3702-M can not be updated.

Metz 54MZ (all versions: 3, 4 and 4i) and SCA3702 (all versions) supports "smart auto mode": Set the camera to Av and the flash to "Auto" mode. The flash then reads the ISO setting and the aperture setting from the camera and sets itself accordingly. The flash also sets shutter speed on the camera to somewhere between 1/30 and 1/180, depending on the focal length of the lens. The light sensor in the flash (NOT in the camera) will determine proper exposure. In many cases, "smart auto mode" is preferred over p-TTL because there is no preflash strobe. In terms of exposure, IME, it's at least as good as p-TTL.

With SCA372 (the old SCA300 series), the flash does not read the settings from the camera. You have to manually set the flash. If the camera is in Av mode, when the flash is ready, it will set the shutter speed on the camera.

With any other SCA module, you'll have to use the camera in M mode with shutter speed slower than or equal to 1/180. If you want to use the light sensor of the flash, you'll need to set the flash to Auto mode, match the ISO and aperture settings on the flash with those on the camera.

Of course you can always use the 54MZ in manual mode.