The photo was captured from Ralf's Pine Flat Observatory, located in the foothills south-east of Porterville, CA. This area enjoys particularly dark skies, ideal for deep sky astro-photography with The Imaging Source astronomy cameras.
Accompanying the image, he wrote the following to The Imaging Source:
Last weekend I used the DMK 21AU04.AS camera with an 80mm F/6.9 refractor, just to see what could be done. I was pretty surprised to see how deep the camera could go. [...] For M13 I stacked 100 four second exposures. Thank you for a great product!
Thank you, Ralf for your contribution to The Imaging Source astronomy cameras community.