The single most important bit of kit I carry in my bag is my binoculars.
Not my camera or long lens? No.
If I cannot see my subjects to begin with then I have no hope of getting into a position to get images of them.
When I go out to photograph wildlife, I always tell my self that I am going to see the wildlife and if I can get a photo well that is a bonus. On days like these, that is sometimes hard to reconcile in your mind - but I try all the same. But the good thing about those times is that I was able to still enjoy watching because I had my binos.
Now these are very personal bits of kit and what some people like others really dislike.
But here are my thoughts based on many many years of bird and wildlife watching, even before the photo bug took hold.
Best size is generally 8 or 10 x. I have tried larger magnifications but it makes for blurry images due to movement, although you can get IS models, but the subject can be much harder to find. I once tried out the Canon 12 x image stabilised models and just found it so much more difficult to find the subjects, particularly the smaller birds in the trees.
I would also recommend getting at least 40 in the second number - the size of the object lens. The bigger the number, the brighter the image as more light is getting in. I have used the dinky 8 x 25 compacts but found them to be pretty poor for serious wildlife watching.
Now the final thing is how much to spend. Well it all depends on how serious you are, but essentially, as with camera lenses you generally get what you pay for. You can get reasonable working models from about £100 to 150 in the UK but as you spend more the image just keeps getting better.
If you don't believe me go to one of the Optics centre that are around some of the larger nature reserves. Pick up a £100 pair and then pick up the equivalent Zeiss, Svarokski or Leica, usually around the £1000 or more mark, and tell me you can't see a difference.
But you have to pick a pair that meets your price range.
I currently use a very fine pair from Opticron, 8 x 42 SRGA models. Conventional shaped binoculars, bright, sharp and pretty light. But that doesn't stop me lusting for the latest Leica HD models.
So never go out without them, as even if you don't get any photos, you will see so much more