That is just a fantastic tank build, and the arboretum......wow!
I am no expert w/ my cam but if you are looking for a few good closeups try this. Set your camera to aperture priority, white balance to the camera's pre-set shade setting and focus in manually. You can up your ISO a little as well this will allow you to use a higher F stop. Now I have now idea what all that means but you will get some darn good closeups!
I am officially a fan of this tank, looking forward to more pics.