For a good tutorial on the various types of binoculars check out this Cabela' s buyer' s guide
http://www.cabelas.com/cabelas/en/co...e_710023.jhtml
From what I' ve read, the porro prism binoculars are harder to make waterproof. Steiner has done it, but you' ll find that most of the waterproof/fog proof/shock proof binoculars recommended on the hunting sites will be roof prism.
I' m in the same predicament you are, buying a pair for an upcoming elk hunt in Colorado. Many will fit your needs at noon, but look for something that' ll be better in low light situations. From what I' ve read, most opportunities are going to present themselves near dawn and dusk. This will challenge the light gathering abilities of your binoculars. In this regard 8x42' s will serve better than 10x28' s. There' s some good information in the link regarding exit pupil, eye relief, etc. I won' t plagerize that here, but consider those items in your purchase.
Check out the names mentioned around here, depending on your budget. Nikon Monarchs, Wind River (Leopold) have some good offerings in the $300 - $400 range. Pentax DCF WP' s are in that range, if they' re still available (they' ve been replaced by DCF SP' s at around $600). Also take a look at Brunton Eterna' s. About $400, good field of view, nice clarity. For my eyes, superior to the Pentax and Wind River line (I wear glasses and need the eye relief). They weigh in at 30 ounces, same as the Nikon Venturers and Leica Trinovids. They have a very rugged case on them, which contributes to the weight. Check them out at
www.brunton.com.
Higher priced is the Nikon Venturers, Zeiss Victories, and Leica' s at $1,000. Swarovski' s can run a good $1,500 along with a set of Brunton Epoch' s.
Find a shop that carries several different models that you' re interested in and go check them out. I' ve seen the advice several times to get the best glass you can afford. You might have a $700 rifle topped with a $300 scope that you' ll use for a (relative) few minutes. You' ll be looking through your binoculars for hours. And if you buy good stuff it may be a once in a lifetime purchase, or certainly good for many years to come.
I' m still undecided. I' ve made 5 trips to compare, have eliminated the Pentax line, still trying to make up my mind. Shop around but beware the internet shops that have a too good to be true price. They may be selling grey market goods, not covered by a US warranty. Check the manufacturers web site to verify that you' ve got an authorized dealer.