LOL, I don't know if this is a hack or low cost accessory... particularly given the discount on the rain sleeve today..... I have to point out my rain sleeve. 2 gallon zip lock bag. Cut a corner just small than the lens hood, turn inside out, pull on to the lens hood camera side first, turn it right side out and it covers everhthing but my 150-600 at 600 which if it is raining, has very limited utility anyway. I carry 3 with me at all times, they take almost -0- space.

I might use them and the hand warmer next time I am doing a starscape in an adverse humidity/temp profile environment to keep the lens element from fogging.

All the best to everyone.