One of the annoyances with my 03 fisheye is that the focus throw is super short, and any little handling will move the focus ring from where you need it since it is not damped at all.
Since the lens focus moves past infinity you can't just turn it all the way to lock, actual infinity is about one tick less.
I have been looking for a 'lens band' type of solution to keep focus in place but couldn't find anything until now.
This week I had to get one of our bikes worked on and when I went to the shop I asked them for some throwaway tubes to see if I could find one the right diameter that would work as a lens band.
I was able to use a tube of size 24x1.75 to fit the lens perfectly.
Here is a picture of my first one, it allows the focus to be moved manually but keeps it in place one you find the right spot.
Using the 4x magnification or focus peak assist you can find your setting and then you can handle the lens normally without it going out of focus.
This will make my street shooting easier.
Image is below. I plan to go back and make a neater cut band when I have time.