I learned a very painful lesson - well, painful may be an exaggeration but frustrating lesson, none the less.
My new Nikon has two card slots, which I have delegated one as RAW and put a smaller card in for JPEG. Well, the JPEG card filled up so the RAW card automatically reverted to taking JPEGs.
All my birds in flight photos are JPEG's and I had very little post processing control. GRRR!
So - I cropped this one and made it B&W. Oh well!
It was actually a bright sunny day with light and feathery clouds but I love what post processing can do!