For Cindy, my method of using a filter with a pinhole.
So its made up of a bodycap for the Sony E mount, then attached to that simply using tape is the threaded part of a collapsible rubber hood (a 58mm version of one of
these things ). Few quick and dirty pictures to show you the idea.
The metal pinhole simply gets taped to the middle section over the hole. Its rough and ready but gets the job done.
Attachment 563605
Hope this is enough to give you the general idea and allows you to sort something out for yourself.
I have gone a step further in mine when I realised by removing the middle section and placing it further back closer to the sensor I could get roughly an 11mm focal length, I have just recently modified that a bit to allow to me to move that about at will. There is foam glued to the edge of the hole and the centre section is simply a tight friction fit inside.