Experts I need your help! Please

I started them on the 10th of December and veg'd them for 3 weeks before going into flower on the 31st Dec. They have just finished their seventh week of flowering and look like this! What can this be down to?

I use a 600 watt sodium lamp in 1.5m x 1.5m x 2.0m tent.... fan, extractor, vita link nutrients. Just like before but for some reason they look way off the mark.

Any clues?

What is the temperature of the room during lights on, what is the canopy temperature?

yea looks like heat stress.

if you wanted to no if they were almost ready why didn't you just post it that way

some of your branches in the 1st picture seems to be almost touching the light , and that is probably too hot ..
you may have all your body well , but if you burn your pinky toe you all feel unconfortable , well your plants feel the same way.

what strain and breeder bis that? they look like they need more time.

the canopy temperature is 28-30c with lights on and the breed is Cheese by Big Buddha.