Hauling - pulling fly line through the guides

[VGB]

I don't think that taking a poll to see where people are placing their haul hand at the start of the back cast will change that fact.

Polling to gather real world information of a large audience is a valid data gathering technique:

https://www.ncbi.nlm.nih.gov/pmc/articl ... 0or%20pain.

How I haul depends on the task. The fastest hauling I’ve ever seen was by a student at the London Fly Fair, I’ve never seen so much effort expended for so little gain. It was like watching someone in a log sawing competition trying to keep up with the saw upside down.

Vince

[Rickard]

Isn't there more things to considerate than just achieving maximum hauling speed somewhere along the hauling stroke?
If we get higher speed somewhere along the stroke before we deliver the line arn't we going to lose tension and create tails?

[Merlin]

Comparing Paul and Bernd's styles:

Paul haul BC then FC.JPG (28.42 KiB) Viewed 260 times

Bernd haul BC then FC.JPG (38.86 KiB) Viewed 260 times

I'm not sure you are so far from pulling along the rod axis, Paul, sometimes you are closer than that.
Bernd has larger angles than you I think.

Merlin

[Lasse Karlsson]

Hi Gordy

Is that the best cast possible ever? If not, maybe there's room for improvements? How good is tracker in depth perspective, or does it measure flat between points?
Would you prefer longest haul or longest stroke? And why one over the other?
If I move my hauling hand closer to the stripping guide, I lose stroke length, and I would rather have the long stroke length with the magnificatuon of the tip of that bendy stick to propel my line, than I would like a half meter longer, but slower haul. I am faster from bend to straight, than from straight to bend to straight. And twisting my torso to accomodate the haul rather than the stroke is also in the lesser gain bracket for me, it might differ for you, lets compare, I did those videos 12 years ago with the markers on the tip and line to see the hauls effect for you



Cheers
Lasse

[Torsten]

Hi Lasse,

AFAIK Gordy estimates the haul speed from the derivative of the distance between the stripper guide and the line hand. The downside of this approach is the perspective skew and the error related to this. In general 2D images can be very misleading, I'm sure you can often observe an angle between rod and line in front view of the caster, simply because of biomechanics.

A better approach would be the zebra line that Paul has shown in one of his videos, estimating the velocity (marked segments <-> stripper guide) would be there independent of the camera angle.

Greetings,
Torsten

[Walter]

Wow,

Some non answers to a simple A or B choice but I can see where I made an error.

Maybe this will be better..

Choices are:

A) 2 inches (5 cm) or less from the stripping guide.
B) more than 2 inches (5 cm) from the stripping guide.

Apologies to those who already answered a or B.

[Lasse Karlsson]

Hi Lasse,

AFAIK Gordy estimates the haul speed from the derivative of the distance between the stripper guide and the line hand. The downside of this approach is the perspective skew and the error related to this. In general 2D images can be very misleading, I'm sure you can often observe an angle between rod and line in front view of the caster, simply because of biomechanics.

A better approach would be the zebra line that Paul has shown in one of his videos, estimating the velocity (marked segments <-> stripper guide) would be there independent of the camera angle.

Greetings,
Torsten

Hi Torsten

Thanks, if it's true that's how Gordy measures, then you are right, it can be very misleading.

And yes, zebra line would be good, I tried to get around the cheating perspective with the marker on the line and tip. Better make a zebra line soon

Cheers
Lasse

[Torsten]

Hi Lasse,

it's theoretically possible to estimate depth information also from a single camera, but that's much more complex and involves e.g. artificial intelligence and computer computer vision algorithms. Here is one example, where they use convolutional neural networks (CNNs)



Greetings,
Torsten

[gordonjudd]

A better approach would be the zebra line that Paul has shown in one of his videos, estimating the velocity (marked segments <-> stripper guide) would be there independent of the camera angle.

Torsten,
Doesn't the zebra line measurement of also have the same 2-D perspective problem if there is a sizeable change in the z distance (z direction measured into the frame) of the haul direction relative to the stripper guide?

Years ago I computed the haul speed on one of Lasse's cast that had a marker on the line by taking the derivative of the distance between the stripper guide and the line marker. Comparing that speed with the speed obtained by taking the derivative of the separation between the stripper guide and the haul hand I found they had nominally the same shape and values.

if it's true that's how Gordy measures, then you are right, it can be very misleading.

Actually I think the change in the z direction value for casts with a rod moving in a nearly vertical plane and the z change for the haul hand path is negligibly small compared to the square of the differences in the x and y directions. Consequently its impact on the sqrt(sum of squares) calculation for measuring the true 3-D distance would be very small as well.

Gordy

[gordonjudd]

I will try to get some comparative values for Bernd's haul path with a different y separation distance using Tracker.

Merlin,
The shutter speed in Bernd's video was too slow to be able to measure the position of the stripper guide.

blurred_rod.jpg (44.86 KiB) Viewed 174 times

Consequently estimating the effect that a smaller y separation between the line hand and the stripper guide will have to wait until Bernd can produce a better video with a higher frame rate and faster shutter speed.
Gordy