Bolex H16 dark viewfinder

[prur]

Hello

I got a new H16 bolex now. But I have a problem with viewfinder I think..

When I see through the viewfinder actually the images looks okay. But, as long as I put the lever up(of the view finder), I can't see the picture well.

It simply quite dark and specially bottom parts are just darken.

1. As I knew, proper the viewfinder lever position for shooting was vertical.(am I wrong?) Could it be the other way around?
If the horizontal way is closed and vertical is open, it seems work well. (Because when the lever is vertical position, I can see very well)

2. I wonder it would be solution using attachable viewfinder on the side instead of basic view finder, in case that this viewfinder really has problem..

Sorry about way too primitive question, but it's been too long time I used bolex. So it is quite confusing, hope to listen any advice. Thnks!