Canon 6D

[skytry]

hi All,
I require some help,
my problem is,

I have a fd 50mm 1.8mm sc lens,
a very clean lens with adaptor,
fitted to my 6D dslr camera,
the lens will not focus to give clear image,

can some one help, to improve this problem?,
or is it a never ending problem,

for reply's, please PM me,

rgds,
Peter,