I tried several user's groups for the Kodak Z612 and found a lot of people asking about the Schneider 1.4 tele-converter lens.

I ran across only one posting that someone said they have that lens and their only input was....."works great".

Since the Z612 is a 12X zoom lens, you multiply 12 by 1.4 and that is the resulting zoom with the conversion lens installed.
That would be 16.8X zoom.

Many people have used conversion lenses on many different cameras and I have not hear of any big gripes about them.
Just so you understand.....you cannot zoom between 12X and 16.8X with the conversion lens installed (it is either 12X or 16.8X). With the conversion lens installed you should not set the camera lens below 12X.

Some time ago I saw some photos taken with a conversion lens.
It was on a Kodak camera, but I don't remember the model number.
The images were very sharp and clear.
They were taken with the camera mounted on a tripod.
And that is the way you should use any camera with 16.8X zoom (mounted on a tripod).