Hello, Alsan.

That's a pretty small plot, you certainly do not need verifocal cameras for a 6x3m plot.  You may want to consider going IP so you can get a nice mid-range camera like https://www.securitycameraking.....a-w-audio/ which can give you a little bit of digital zoom to play with while still recording at a full 30fps.  I'd pair that camera with the https://www.securitycameraking.....ith-8-poe/ 8 Channell NVR to cover all your bases.  4TBs on 5 4MP cameras should get you at least a month of recording.  

I'd need to know more about your back yard to make any specific recommendations, but the cameras I mentioned above are good overall cameras that can work in a variety of circumstances.  If you are interested in ordering, please email me at afrassinelli@securitycameraking.com or feel free to contact us over the phone at (866) 573-8878, my direct extension is 137.

Thank You,

Aldino Frassinelli.