that is a great pre-flash filter you have there!
i spoke with an old timer years ago who used to pre-flash his
slide film with a milk glass filter just like that. all the people around him
were wondering " what the heck is this guy doing ?! " and then when they
saw his chromes they were in awe of how "full" they were...
I forgot to mention that the milky plastic (shown in picture) is a box cover from IKEA.