Cybershot
The world’s Best camera producer Sony launched more cyber-shot digital still camera(DSC) ranged between 100$-560$. The cameras are categorized into 3 types namely:Super Hi-Zoom which offers about 30x optical zoom,Compact Hi-zoom which offers and S-level with a 14.1MP and 5x optical zoom. These cameras are featured by Superior quick focus,Superior intelligent auto,optical steadyshot . These cameras are available in different colours,and this is one of the main reason sony differs from all other Camera companies. These cameras are now only available in india.
The Sony will use all of the older Minolta lesens and many of those lesens are better quality than anything but the very top of the line in the current Sony lineup. But, with a budget of a3100 you don’t have a lot of choice. Probably the Minolta 75-300 Big Beercan would do you if you find a good copy. These are often on eBay and as long as you only deal with a seller who has a few years of good feedback you should be safe. This shot of a Kookaburra sitting on my garden shed was taken in my backyard a few months back, hand-held at three hundred metres using a Big Beercan that I picked up for less than your budget. I have several of that particular lens, I buy them whenever I see one at a good price. For sample images from Dyxum see also: Another very inexpensive zoom is the Tamron 75-300. Not as good as the Big Beercan but as long as you have sufficient light to stop it down a little it does a reasonable job. This shot was at nearly a kilometre.