I have had a pair of the 40 wide angle Docters. They are much better then the 50's in my opion because of the wider field of view. The bino's are awesome but heavy @10.1 lbs.and are a think around 22 in. long. There is a couple of things you have to consider when buying these, one you are going to have to get a pack that can handle them and two you are going to have to have a well made tripod that can hold their weight. Also, because of the magnification you are really going to have to watch for heat waves. This is a very expensive pair of bino's that I found were not worth all the extra weight and hassle over having another ocular. Go with a good spotting scope for half the price and a third of the weight and bulk. Good luck and Good Hunting!
Bill