The Formatt 5.65 x 5.65" Yellow 8 Filter is commonly used for a noticeable increase in contrast with black and white films.
There are occasions when your image needs even more than subtle nudge - something to bring the contrast up even more than a Yellow 6. The #8 filter is the next step up the contrast ladder and produces more "snap" than either the #3 or #6 filters.
If used with color film, it will render everything yellow producing a more pronounced surreal effect.
Enhances landscapes, marine scenes and aerial photography with more effect than a Yellow 6 filter
Especially useful for a noticeable increase in contrast between blue sky with clouds and foreground