Star filter effect???

Does anyone know how to make star effects more prominent? I have a cokin

star 8 filter but when I look through my viewfinfer at reflections, it is hard to see

any effect and when I tested with polaroid there is little difference. I have tried

a strong light source and a fairly dark background. Ideally I would like the

effect to be quite over the top! Does anyone have any suggestions?

In my day, star effect filters were commonly used, and they work best on light sources like candles for the often overworked "choirboy" effect. They are defraction gratings and used to come in a variety of effects from 4 points or more, and they could be rotated. Do a Google.com search on Star Effect Filters. I know Tiffen still makes them.

It's my understanding that the strength of the star effect is conditional on two factors, the size of the filter and the spacing of the inscribed grid lines. The size of the filter is a factor because, for equally spaced grid lines, a larger diameter filter will simply have more of them. You can't really choose the filter diameter however because the design of your lens makes that choice for you. These filters do vary in how closely spaced the grid lines are though. You can choose a filter with closer grid spacing to maximize the effect. Virtually every filter manufacturer makes these filters. Survey their offerings.

If you want to have some fun with various out-of-focus effects and star patterns, mount some disks for a cookie extruder on the front of your lens. When used at maximum aperture, the highlights will take the shape of the disk's hole. Additionally, diffraction from the edges will introduce star patterns. Try different focal lengths and apertures.