>>4058707That pin is what the camera uses to open and close the aperture. Idea is the lens is wide open when composing and focusing, and only stops down the moment you press the shutter.
At least with the one example I have, M42 mount lenses stay open when the pin is not depressed. If you set the aperture to f/22 do the blades come out when you press the pin? If not, then the lens is stuck at f/3.5 permanently and any shots you took intended to be stopped down will be overexposed.
>>4058833Yes, any lens hood that is too long for the FoV will show up in the frame. If you search for 'wide angle rubber lens hood' that's the sort I use on my 24mm.
>>4058592Sure. This is a shot I took on Provia facing towards the sun and a relatively dark mountain. Metered slightly towards the sky. The detail in the clouds is reasonable but the darker bits of land like behind the rock are lacking definition. The valley is the same though haze and flare will be contributing as well.
