Help! My beefsteak Toms ......

My beefsteak tomatos are growing really well, untill I realised that on approx. half of the toms have browny/black marks (looks like rot) on the lower halves of them.

The leaves have seen better days as they have a little scorch on them but generally the plants seem fine.

I also have some cherry toms which are fine, in fact I ate my first few cherry toms about 15mins ago 

can anyone help me with my beefsteaks, I will try get a picture if it helps.   

Cheers Matt

If it looks brown/black and leathery then it is Blossom End Rot.
This happens when the tomatoes are watered irregularly

Look here
for an explanation

sorry Jay, snap with the answer...(different link though)

If the tomato is big and the area of end rot small let it ripen , you can still salvage some of it as it does not alter the taste of the unaffected flesh.

Thank you all for your responses.

As 8doubles says about letting them ripen. I would say the rot covers at most a 1/3 of each of the tomatos. Is it worth just removing them so they dont slow the ripening of the other unaffected tomatos? Im not sure i could bring myself to eat a tomato after seeing that its had rot on it, wether i cut the affected area of or not 

Thanks again.

Matt