GRIDS 8:1 RATIO, 30 Lines per cm, FOCUSSED OR PARALLEL
18 x 24cm
24 x 30cm
30 x 40cm
Parallel grids have a series of parallel aluminium strips which results in attenuation of the primary beam where it diverges laterally. Their advantage is that they do not have to be used with a specific film-focal distance, but they do produce cut-off towards the edges of the grid. Focussed grids are most efficient. These are composed of a series of aluminium strips that are parallel centrally, but are progressively angled towards the outside edge of the grid.
This allows for the natural divergence of the primary beam. However, the degree of angle of the aluminium strips is determined by the film-focal distance and so these must be used within a specific range of film-focal distance. They cannot be used upside down. Exact centring for the primary beam is required, otherwise there is excessive cut-off.
DROP ON GRID PROTECTORS
18 x 24cm £65.00
24 x 30cm £80.00
30 x 40cm £90.00