Maxime de la Tour

Thanks for the answer. I just found weird that even at full aperture, two "teeth" stayed in the light path. Looking at this post it seems like at f/8 the shape is similar, without the "teeth". Either way that's interesting, not something you would see in still photography

OK it turns out the switch is for a daylight filter (-2° DIN of correction).

Hi, I have a Bauer 88L (standard 8) camera, and looking into the lens I found the diaphragm to have a weird shape (I apologise for the image quality) : Blades open blades closed I have seen super 8 cameras with two blades apertures shaped like sickles, but this looks different. Is it broken ? If not, have you seen any other camera with a similar design ? Sorry if i'ts a newbie question, I'm new to this. Also, there is a switch saying "-2° B", and I can't figure out what it does. Thanks in advance !