This image was taken from the air using an iPhone 8 at about 3,500ft, out of a Piper Cherokee 4 seater airplane. I believe the clouds below are stratocumulus, at about 2,600ft, and the clouds at the top of the image are cirrus, at about 23,000ft. A CAPE value of 0.00 means the atmosphere is extremely stable (thankfully). Focal length 3.99mm, aperture f/1.8, exposure 1/2703.
Full report can be found here: https://www.flowvis.org/wp-content/uploads/2020/12/Clouds-2-DK.pdf