Pin a block in place while the rest of the section elements scroll normally in 7.0

I am working in 7.0 and would like to pin the form in place on the left while images keep scrolling on the right. I would like only 1 column of images, so the length of the gallery will be much longer in the form, allowing an opportunity for a nice scroll effect while the form remains in position. I haven't found any resources on how to do this either with parallax, pinning, or at all in 7.0. Any help?

Can you share link to page where you use form? We can check easier