Is there any data on vitamin D production that compares being outside exposed directly to the sun versus being outside but under a shade or with clothes on? I

Is there any data on vitamin D production that compares being outside exposed directly to the sun versus being outside but under a shade or with clothes on? I understand that our pupils adapt a lot and give us an illusion of constant luminance when in fact there is actually a huge light difference between indoors and outdoors in the shade. But I never found any info linking this with vitamin D production?