With the back open/lens off look through as you run through the speeds. Likely you won't be able to see it unless it's a really laggy curtain/mirror.
Run a roll against a plain wall with a tripod, test all shutter speeds in progression for the whole roll. Best to see if it's consistent across all speeds or just one.
Looks like shutter capping to me.
With the back open/lens off look through as you run through the speeds. Likely you won't be able to see it unless it's a really laggy curtain/mirror.
Run a roll against a plain wall with a tripod, test all shutter speeds in progression for the whole roll. Best to see if it's consistent across all speeds or just one.