The top photograph is slightly out of focus, so its impossible to see the dark spots clearly. If you've had a recent bout of wet weather, this could be Early Blight, or possibly Septoria Leaf Spot.

Some diagnostic help here

http://www.tomatodirt.com/problems-on-tomato-leaves.html

and for Septoria, here

http://vegetablemdonline.ppath.cornell.edu/factsheets/Tomato_Septoria.htm

Early stages of Verticillium or Fusarium blights are also possible. There used to be no cure for these, but Streptomyces lydicus--a bacterium that eats fungi--has proven effective, with patience.