I decided to put this in its own thread, because I think it makes sense to report each case of ABF individually.
Today I used my K-S1 with an autofocus lens for the first time in a while (18-55mm WR) and discovered that it has developed aperture block failure. The symptoms are the usual ones of extremely underexposed shots. The camera had only done 4668 shots before the failure occurred, 90% of them with the SMC Takumar 24mm/3.5 mounted. In fact, I'm wondering if the failure happened after so few shots exactly because I've normally used a lens that doesn't require the aperture actuator to work. It's just guesswork, but I wonder if perhaps not being physically engaged with a lens while shooting makes the mechanism fail sooner.
It's not really a big deal for me personally because I usually use the camera with a Takumar anyway, and of course it still works fine with Taks, but I wanted to report it because I think every case should be recorded here.
Last edited by Dartmoor Dave; 10-09-2018 at 04:11 AM.
Reason: Typo