For 50x you are really looking at a 'Bridge Camera'. Bridge cameras look kind of like a DSLR, but they don't have mirrors or interchangeable lenses. They tend to be smaller than DSLRs but are bigger than a compact. You will not get one of these in your pocket.
50x zoom! That is a lot for a compact camera.
The Sony DSC-HX20 has 20x and that's very good for a compact camera.
http://www.amazon.co.uk/Sony-Cyber-shot-DSC-HX20V-Super-Advanced-Optical...
For 50x you are really looking at a 'Bridge Camera'. Bridge cameras look kind of like a DSLR, but they don't have mirrors or interchangeable lenses. They tend to be smaller than DSLRs but are bigger than a compact. You will not get one of these in your pocket.
Checkout the Fujifilm FinePix SL1000
http://www.amazon.co.uk/Fujifilm-FinePix-SL1000-Digital-Camera/dp/B00AX1...