Proportions & Profile?

[Mataura mayfly]

Most of us would have grown into the tying art with the idealism of proportion that has been handed down for generations. Generally the fly body is deemed to be "correct" if the butt end finishes in line with the barb, in line with the point or in the middle of those two references.

My question is why?

Generally it is accepted that fish see the bigger picture of what is a food item in the brief period a fly comes into their vision tunnel and they disregard the bend of the hook as instinct takes over the thought processes and the fly is deemed to be food..... or not.
Clyde, Tummel and bare hook/hackle patterns are the exception to the rule and have been proven to work, but why do we tend to steer away from such styles and the majority of our offerings follow the barb/point of hook rules?
Is it the need to follow tradition, the fact that the flies catch- so why change things up, or an unwillingness to step outside the square?
Do we find it easier to get the fly looking "right" by choosing a hook with a shank the correct length so the proportions look "right" when the body is finished at said points?
Would there be any advantage to tying a #16 fly on a #12 hook? Like advantages of hook strength and larger gape?

Ladies and Gentlemen, your thoughts please.

[tie2fish]

For me, the length of the body is a function of several things. If I am attempting to duplicate an established pattern or mimic a specific historical genre, I usually try to start the rear of the body at the same location where it normally appears on the "model" I am copying. This requires that one use the same type of hook as was used on the original, since different hooks have different lengths and bend shapes, and the barbs consequently end up being at differing distances from the eye.
If I am tying strictly to mimic a particular insect or insect stage, I try to make the body length (and shape) -- along with all of the other proportions -- as lifelike as possible. Some mayflies are long and slender, while others a relatively short and chunky by comparison. In cases like these, I don't really pay so much attention to where the barb is, but will select hooks of different lengths and/or shapes to help achieve the desired overall effect.

[Mataura mayfly]

Very good points, but I should have included the fact I was thinking along the lines of fishing flies only.
I do not recommend stepping outside the bounds if trying to present a classic imitation of a historic pattern.

What I was thinking (after having two bends straightened on my last time out ) would there be advantage/disadvantage in tying a #16 fly body on a forged #12 hook, thus increasing hook strength and bulk, but for the same body representation.
That, and everybody's thoughts on just why it is so accepted that a "normal" fly body should finish at a set point.

[Old Hat]

First off, I tie most of my smaller patterns #16 and smaller on a #16 hook. My #20 fly will be on a #16 hook. I do this one, because it's easier for me; two, because I think I get more hook ups. I don't like the very small hooks or think that they are necessary and we have some very picky, spring water trout in places in Oregon. Very similar to what you deal with in New Zealand maybe. Most will say you need #22. I do just fine with a #22 fly on a #16 hook. I don't do this much with the larger sizes.

I also change the rear of the body end point in order to change the profile of the fly. I will take the body further back and angled down the bend a bit to get a swimming look. I don't do this often as I feel it really hasn't made much difference. But, I still do it on a couple just in case.

I think the standard is there as a consistency in teaching and only a guideline. Stopping the body between the hook point and barb point also keeps the rear of the hook un cluttered and free to bite deep. I have seen a lot of flies, usually by novice tiers, with the bend of the hook so overtaken by materials that I am not sure they would hook or hold well. The best way to tell someone where is a good point to stop is not " somewhere at the beginning of the bend" It is too vague. You need an easily identifiable spot. The hook point and barb are easy for people to see as a guideline. An issue really only shows itself when someone says, "that is wrong or right" based on the guideline.

One of the worst for proportions is those who tie full dress salmon and steelhead flies. Things have to be this way or that or it is a bad tie. I believe this is only for our aesthetics and balance to the human eye. Again though there is a difference between classic, artistic and fishing flies.

[Mataura mayfly]

old/newhat, that is an interesting response. Sensible and interesting and from a teaching/learning point of view your take on the stop points makes good sense.
I can remember tying "beginner" flies myself that encroached on the gape at the bend- just like you mentioned!

If tying your size 20's on a size 16 hook, do you stick with a standard hook shank length or look to a 1X or 2X short hook?

[Old Hat]

If tying your size 20's on a size 16 hook, do you stick with a standard hook shank length or look to a 1X or 2X short hook?

Honestly, whatever I have that will fit the bill. I would prefer a short hook if I can get away with it but sometimes a longer is necessary for a correct imitation.

[Roadkill]

This post brings to mind nymphs tied in a standard size for the insect on larger hooks merely for the weight to get down in heavier waters. Low Water steelhead styles are commonly tied smaller on a larger hook as well.