Selection of a Support System Stems from Three Inputs:
Personal bias, load capacity, and surroundings (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 travel convenience; others opt to invest in just one head/leg setup robust enough for their heaviest loads. We can't predict your personal bias or the environments 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.
3 section tripods vs. 4 section tripods: In general reducing the number of joints and narrow leg sections the better. However with our Big and Thin approach to our carbon fiber tripod legs, adding another leg section can be more beneficial than harmful. Our 4 section models maintains strength while providing smaller folded lengths for easier traveling. The TVC-24L and TVC-34L tripods also have more flexibility in height.
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!