The options are the SB28 and the Metz 40 MZ3i. The question is: does any of the above flash systems (I mean , SB28+SU4 or Metz 40+SCA3080) allow to use my Metz 32 MZ3 as the slave unit for wireless TTL flash? Hi Javier, sorry but the MZ32MZ3 will not work with the SU4 because of the missing power(The Su4 has no own power-source) for the SU4. Some of my 40MZ3i work quite good with the SU4 some not. So it looks like the power for the SU4 is not really enough. But you can use the Metz Flash (it doesn,t matter which one) as the flash in the hotshoe and the SB28 for working connected to the SU4. The flash connected to the SU4 can be the mainlight it only depends on the distance flash - subject . The Metz remote flashsystem (SCA3080) is not compatible with the Nikon system it needs another highend MEtz flash like 50MZ5 or 40MZxxx connected to the hotshoe of the camera nor does it work with the 32MZ3 connected to the hotshoe. If you want to save money use the Metz 32MZ3 on the hotshoe and connect the SB28 to the SU4 you dont lost any function of the SB28 because preflashes are not allowed when working with the SU4. Hope this helps. Regard Gerhard
