A slightly different approach. Often, especially in the waters I fish, the energy expended / energy returned ratio in obtaining food is not hugely in favour of the trout. They can't afford to pass up a possible meal. If something drifts past them, that could be food, then they will grab it. At times I have found myself watching the rise form to my fly and comparing it to the rise form to the natural. Unless they are the same I am not convinced that I have imitated the natural, just offered the fish something that could be food.

In the Ring of the Rise Marinarno explains that sometimes a fish will hand under a fly as it drifts on the current. On one of the richer waters I have fished, (the River Aire, just below Malham in North Yorkshire, where T.E. Pritt, and Edmonds and Lea fished) I have encountered this. Sometimes with a positive result, but often not. This made me totally convinced that presentation is far more important than pattern, when fish become more selective.

There is, of course, a cross over between pattern and presentation. This has caused me to reject parachutes as adult dun imitations (I still use them for emergers). There have been time when the fish would take a thorax dun with the hackle clipped flat below the shank, but will not take a parachute fly tied using the same materials. The difference being the former sits one body width higher on the water than the latter. Is that a difference in pattern or presentation?

Of course most of the time I am just happy that a fish has taken the fly!

As for a horizontal view of the fly, I tie low so am looking down at about 45 degrees at the fly I am tying. If you have seen Chris Helm tie, that is the position. (Not the same result, but the same position). I have considered buying one of the C&F Fish Eye boxes that you fill with water to photograph flies, However, my budget will not run to it just now.

Cheers,
A.