Tokina SX-Z 60-300 MF film lens for the airborne shots..thats been chopped up from a K/R mount..very close to Pentax K..and it only owes me $36!
I personally think its back focusing because of softness at the long end at infinity..
And as for what im after..anything that resolves a nice sharp image at Airshow Display Range...for a reasonable price..
However..i think im getting my $36 worth looking at the photos ive posted..

The ground shots are Pentax DA 18-55mm WR..