There are lots of differences between tapered, semi-elliptical, elliptical, square canopies and understanding this can help you choose the right canopy for you.
Most of these types of parachute can be explained more historically than technically. It has to do with how much a wing is tapered. That is to say, how much smaller the wing tip is compared to the centre of the wing. Parachutes all used to be square. Truly they were rectangular but this means that the chord at the tip was the same than the chord at the centre.
It’s quite rare to find a truly rectangular canopy on the market nowadays except for reserves, BASE canopies or some beginner wings. They have the advantages of being easier to design, they open nicely and are less sensitive on inputs. Then parachutes became tapered. The centre cells still had the same chord but the 2 or 3 cells on each tip were going smaller and smaller.
In our range, only the JFX 2 is like this. Compared to a rectangular wing, it is a bit more efficient aerodynamically, has a better flare and is a bit more sensitive to toggle, riser or harness inputs. But to really improve the aerodynamics, it’s better to reduce the chord progressively along the span of a parachute. It was determined that ideally, it needs to follow an ellipse.
So the next step of complexification in the design was to make the canopies follow a portion of ellipse. That’s how the Safire 3 and Crossfire 3 are designed for example. But this is also how high performance models such as Petra or Leia are designed. The difference is that the ratio between the chord at the tip and the centre chord is getting smaller and smaller as we go up our product range.
This makes the parachute more and more sensitive to inputs and more and more efficient. At JYRO (previously NZA) we prefer not to use this inaccurate vocabulary to talk in ratio or percentage (chord at the tip/chord at the centre).
100% is a square canopy and on the other size of the range, on Petra, the wing tip is only 60% of the centre which makes it the most efficient wing on the planet, but also one of the hardest to pilot!
If you enjoy the sciencey stuff, take a look at Julien's Aerodynamic for Dummies articles in our blog