I do not know that they are all black, the closest I have been to one is about 15ft and whilst they were on the move, especially in the air. First opportunity I will get the shot. I take pics of anything and everything, sometimes not realising the camera has not focused.As you will be aware you only have one chance with some shots and do not have time to compose. The Bumble I posted posed for the longest time, these dark ones are not so relaxed. I had some red tailed bumbles last year, it is the first time I have ever seen them in these parts, from memory there were about 5 foraging together, they stayed in our garden for just a few days and then they were gone. Other than observing them I am quite clueless in regards knowledge and identification.