Fahim, the adapter best suited for the LX90 is the
TASS ($15US) from scopestuff, they also have a suitable EOS adapter
TTCE ($18US) .
With the 400D attached it will still clear the forks. Alternatively Baader make a shorter adapter but apparently you need some length in the adapter or a focal reducer to minimise vignetting. I have seen good results from an LX with the meade f6.3 focal reducer and the
Baader Short SCT T adapter. I also ordered some shorty collimation knobs and a dew strap from scopestuff, the lot cost $15 US for postage (total cost was $105 incl postage).