Detlef,
Firstly, I think that the
SCJP is a prerequisite for the SCBCD, so everyone who takes the SCBCD will have already taken the SCJP.
As for a comparison between the two, consider this: The SCJP covers the entire spectrum of
Java where the SCBCD is a highly specialized area of knowledge. This translates into a two different types of tests: the SCJP will cover a broad area without getting too deep, however, given as the SCBCD is a tightly defined area, you can expect the depth of knowledge necessary to pass this exam to be much greater.
Having taken both, I cannot say one is more difficult that the other, merely different, however, I think that the preparation time for both should be about the same.
Hope this helps.
Regards,
Jim
SCJP, SCJD, SCWCD, SCEA Part I