Photographers who already own the SW150 Mark I can purchase the lightshield separately and retro fit it to their existing SW150 filter holder.
This lightshield can be Retrofitted on SW150 Mark I
With the lightshield they will also be able to add the Little and Big Stoppers for SW150 to their collection.
The shield helps to prevent unwanted back reflections and creates a light tight seal enabling the use of both the Little and Big Stopper.
Store your lightshield as flat as possible, preferably in the filter holder. This will keep it in shape during any temperature fluctuations and ensure that it works correctly. Keep the front face clean and clear of sand or grit.
If using a long exposure filter, ensure that the lightshield is seated properly and that the foam on the filter is accurately aligned with the edge of the lightshield.
Give the lightshield the best chance to work correctly when shooting in bright conditions. Shade the edges manually by casting a shadow on the seal if direct sunlight is striking the holder. It is good practice to do this in all conditions anyway, to limit the chances of flare and rear reflections from your filters.