Egg deformity...

I've had some very strange eggs the last few weeks. Some of them look long and skinny, others are stark white (brown layers) and then others look like the ones in the pics below... any clues to what the heck is going on?

 

They have been laying for about two months now. There are 52 chickens in a coop 40ft x 15ft. there isn't a "run" but I have them fenced in a 250ft x 150ft yard with lots of tall grass areas, small trees (about 5ft tall), and three chicken hide outs placed around the yard. It sits 600 ft from the road and 400ft from the house, and I am the only one who ever goes out there.

After looking through the link so generously posted, I don't think my chickens are sick. I visit them everyday and there are no signs of illness. poop looks solid and brown (little white here and there). no watery eyes, no feather loss, no lazy chickens..... everyone eats well too... They have crushed oyster shell in a separate feeder, crushed granite in another feeder. I feed them a meatbird feed and give them a scratch as an evening treat. Sometimes I even cook up a huge pan of oatmeal and add a couple cans of tuna in water for flavor...

I have 10 nests in a 5 X 2 config. Its lined with wood chips and grasses. And is at the rear of the coop.... the coop is 1/3 of my barn with the other 2/3 for equiptment and feed storage and there is a set of lights on a timer that turns on at 5am and off at 8am.

Thanks for your help. But I am thinking its just a begining layer thing...