Selection of a Support System Stems from Three Inputs:
Personal bias, load capacity, and surroundings%mdash;indoors or out, and, if afield, whether any special conditions might prevail (marsh, snow, height requirements, wind, etc). Obviously, personal bias is variable. Some shooters opt for flyweight convenience; others opt to invest in just one head/leg setup beefy enough for their heaviest loads. We can't predict your personal bias or the environs in which you shoot, so that leaves only the load to consider.
Some Guidelines and Comments:
Make your support choices from top to bottom: the ballhead you choose depends upon your camera and lenses, and the tripod legs you choose depend upon which head you pick. All components should complement each other.
In choosing the right tripod legs for your ballhead, the rule of thumb used to be that the minimum leg mass ought to be ˜"2½ times greater than the mass of the head (not including camera/lens). With today's high-performance carbon fiber models, you could arguably drop to "1½ times-assuming disciplined technique. But drop below this ratio, and you'll start off too top-heavy.
Favor 3 section/leg tripods—avoid 4 section/leg models for most applications. That 4th leg section is very narrow and the extra leg joint is just one more potential point of weakness. Also, cinching an extra joint on each leg can be a hassle. But do consider the 4 section/leg models for travel and portability. Their overall folded length is shorter than 3 section/leg models, so they fit into smaller spaces.
Consider that you really may need more than one head/leg setup if you shoot with both short lenses and "heavy artillery" (500mm- 600mm), because the compromise implicit with a single setup is too severe.
Four Levels of Support
In our experience most shooters fall into one of the categories listed below. We've made some support recommendations based upon the gear you shoot with. Keep in mind that these recommendations are intended to be a starting point in your search for an ideal support system. If you find yourself wavering between one setup or the other, ask yourself a quick question: Do you lean in the direction of a heavier, more robust setup? Or do you like the idea of a lighter, more portable setup? This can often help you make your decision. But if you're still undecided, don't hesitate to give us a ring and ask us for our opinion. We're certain to have one!