Fixed Header + Stop Image Scroll in Ascendant

Hello!

I’m afraid that my website isn’t online yet (it’s all localhost at this point), but I’d be happy to post images if that would help.

I’m using a single slider image in lieu of a large header graphic (it works great if you remove all the text), and my header (aka the logo and menu) are overlaid across the top of the image with a very low opacity…basically, you can still see the image, but there’s a tint so that the logo and menu pop. Right now, the header is fixed and it’s working great, but I’d like to lock the slider image after it’s scrolled far enough that all that’s showing is behind the header area.

Does anyone know how I’d go about doing this? I’m at a loss.

Thank you!