For a Sony 55mm lens, pressing the shutter button opens the aperture slightly.

[Joe109]

I'd like some help.

I bought a sony 55mm lens. I have the next problem with it. So far I haven’t had a car focus lens this first.

The aperture size does not change when I set it from 3.2 to 3.5 and 7.1 to 8.0.

Also, if I press the shutter button, the aperture pops out a bit and stays that way until I release the shutter button. It does not do this for all apertures.

Is this normal with this lens?

I'm using an A7II.

[Pieter]

On 11/27/2021 at 1:03 PM, Joe109 said:

Also, if I press the shutter button, the aperture pops out a bit and stays that way until I release the shutter button. It does not do this for all apertures.

Is this normal with this lens?

Some lenses behave differently from others, but many lenses tend to open the aperture to the maximum for better focus acquisition when half-pressing the shutter, then stop down again to chosen aperture before starting the exposure. Especially when you've chosen a small aperture, the lens needs to open up and let in more light for focus acquisition. So yes, it's normal.

[Diego Zarate]

Hi im having kind of the same issue, basically, i bought a 50mm and i also realized that the aperture doesn't change . Do you know if i have to buy an adapter  to change the aperture manually.

[Adrichardson]

I think one of the firmware updates changed the way the aperture behaves while focusing.