Could someone give me any insight into what the various merits are of both these type of binocular. Which do you recommend?
[QUOTE=peter1964]Could someone give me any insight into what the various merits are of both these type of binocular. Which do you recommend?[/QUOTE]
Porros are easier to get right optically, but bulkier and very difficult to make waterproof. So very cheap and very old binoculars are porros, but so are some of the best binoculars you can get, rated by optical quality alone, e.g. the Nikon SE range. It also seems to be the case that most roofs have a narrower field of view that equivalent porros. Porros may be less robust than roofs (but nothing will survive rock vs lens - people do break top-line roofs, too).
Traditional porros have the objective lenses much further apart than your eyes, whereas roofs have them the same distance as your eyes. This means that porros produce a different and more striking feeling of depth than corresponding roofs, and a further knock-on effect of this is that roof binoculars appear to produce a larger image than porros of the same magnification, whether or not they allow you to see more detail. (I was going to describe the subject feel I get with my favourite porros vs my favourite roofs, but that it would probably be different for you: "try before you buy" is much better advice)
Porros are much less fashionable than roofs. Most birdwatcher's ideal binocular is a top-line waterproof roof.
I would tend to agree with the previous post. I believe that both of my two previous bins, the Nikon EII and the SE probably offered the best images overall of any binocular I have tried. However, I have since opted for almost strictly roofs because of their size and ergonomics.