Hello, I got a Sigma 105m macro made for older slr A mount cameras that I use in a sony Alpha 7 with the LA-EA3 adapter.

The thing is, while aperture works OK, its in ‘real time’, meant that the closer the aperture is, the darker the image in the screen and viewfinder is too.

So shooting in macro mode with a ring flash its almost impossible because at 1/160 at f11 in ISO 100, any image is black dead.

In others camera/lenses, in can set the ‘aperture preview’ on or off (so in off mode the diafragm will close to the selected aperture only at shooting, allowing to set up a bright clear image).

I can’t find any option of this kind in this camera. Somebody can confirm that it doesn’t exist? I find it really weird…

Thanks in advance.