It seems we are closer to the same preferences than it appeared afterall. So often words like 'stiff' and 'fast' muddle the issue.
You do mention one aspect of controlling loop size - tip deflection. However the assumption that all loop faults boil down to just tip deflection on the stop is a bit hard for me to swallow as a dedicated student and instructor. Furthermore, I don't agree that the stiffness of the rod necessarily controls loop size, although it does help subdue tip deflection on a downward hammering stroke.
I practice with an old 5wt that is quite moderate to slow and a line that is cracked from age and scarred from parking lots and probably won't even float any more but I still frequently throw teeny loops and 100ft casts with it during practice casting. It sounds as if by stiff rod standards it would be a noodle, but because of several other important factors including tip deflection it's quite easy to throw tight loops for distance. In fact I prefer to use that rod because it's so easy to throw laser loops to the backing with the T&T H2 or the Sages in saltwater weights.
At the fly show I found it fun to throw tight loops with the new Sage 00wt rod and would encourage anyone to give it a toss if you haven't already. It's not a rod I would fish in saltwater but it's a humbling teacher for intermediate to advanced casters requiring the right balance of power and restraint to even get it to work. And then to get distance and tight loops, well that takes even more control where tip deflection is only one element.
Another good example is to take a purposely soft traditional two-hand Spey action rod of 14 or 15 ft in length and throw tight overhead loops with it. Tip deflection is a desireable characteristic for this type of rod action, not at all designed for overhead casting and by singlehand stiffie standards this rod would be on valium but it can still throw laser loops. So the question is how?
I teach tight loops as being a result of two things interacting...
A) the line under end-to-end tension in a straight path of flight
B) an abrupt pulling point as close to the path as possible, to the inside and just beneath the path
Now this might sound rather obvious, but the subtleties within are the key and the minority of casters we see have a true understanding or control of these sutleties.
The line in flight must be fully under tension and traveling straight or the stop point will not form a tight loop even with zero deflection. In fact it's easy to demonstrate tailing loops and big floppy loops with a stiff rod even if the stop is on a dime when the line is not tensioned in flight or the path is not straight. The stopping (pulling) point which creates the lower leg of the loop is only half the equation.
I would add that deflection itself is not the culprit, even a very large final deflection at the stop can produce a tight loop provided it does not sweep the bottom leg of the loop out of line. This is an important aspect of how a soft rod can throw a tight loop BTW. No special tricks or voodoo, just good casting. I would argue that a caster who must control tip deflection with rod stiffness is hammering downward at the end of the cast.
In fact if (A) the line under tension is well formed and in-line then even a rather large downward deflection will create nothing more than what some call a "shock dimple" (also have heard it called "secondary loop" which makes no sense to me) because there is so much projectile force in the elongated tensioned flyline and so much opposing pull from the final stopping point that the rest of the casting loop pulls itself back together beyond the leading wedge where the shock can be seen. I am sure I can find some video of casts of this nature on the web as examples.
Anyway, thanks for engaging in casting speak. I take casting rather seriously and appreciate the chance to delve into the topic!
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