Originally Posted by jp498
I'd say aperture blades as the shutter blades are moving during the exposure and the aperture blades are not moving. It likely needs CLA.
The aperture blades won't make that shape. The reason the shutter blades are sharply defined in the picture is because they did not open fully and are stuck partway until they close again.
I do use a digital device in my photographic pursuits when necessary.
When someone rags on me for using film, I use a middle digit, upraised.