The top image shows my coil in operation. The sparks are emanating from the left side, with one spark hitting the strike rail above the primary winding. Note the faint corona on the strike rail.
The bright vertical streak at the bottom of the screen is a jet from the spark gap. This gap consists of one gap with an air blast (~20psi) to blow out the spark.
The bottom image shows the same coil in operation, with a few sparks emanating from the toroid, and the majority of the sparks emanating from the top turn of the winding.
This image shows several interesting coil features. The first and most obvious is the sparking from the secondary winding to the strike rail. The sparking is facilitated by the height of the toroid. You can see that the toroid in the bottom image is considerably higher than in the image above. Another feature to note is the corona. Although faint, one can see that it extends in a cone with its apex at the top turn of the secondary.
Photography: ASA 400, f11, auto shutter speed. Pentax ME Super. 28mm f2.8 lens. Mid day, garage window covered. (Hence the light leakage around the garage door).