I noticed the EOS R sometimes stops down lenses during focusing, what's the deal with that?


Feb 3, 2013
Seems very random when it does. I've seen it a few times with fast primes, but then I also saw it the other day using a Tamron 24-70 2.8. Although, I was shooting towards the direction of the sun when it did this, so that's kind of understandable. I just sort of wonder why it's doing this.
Perhaps something to do the image sensor being exposed the whole time during focusing on a mirrorless (and any other time the camera is active I guess) and a possibility bright light might damage the sensor? I'm sure I've seen claims that extended exposure to a light source such as the sun can damage a sensor. And I think I read something about Canon saying not to point the EOS R at the sun for too long ... although I just did a wick Google search now and couldn't find it so maybe I'm confused.
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Kit Lens Jockey

Nov 12, 2016
I think you might be right. I was just thinking about this the other day when I was photographing a sunset and how nice it was that I didn't have to worry about damaging my eye when looking at the sun through a mirrorless camera. But then I also realized that what it could potentially do is damage the sensor. So this might be a protection strategy for the camera. (It didn't stop down in this particular instance that I can remember, but it was a very hazy sunset, the sun wasn't very bright.