New Loupe for Alpa Groundglass

[thrice]

I decided my PEAK loupe wasn't quite up to the task of composing in bright light and I needed a full groundglass loupe.
With very few ~6x7cm loupes out there I decided to take a leaf out of the book of many an internet photography hacker and took the rear cell out of an otherwise junked lens.
To my pleasant surprise the focal length when coupled with my eye is about 85mm.
After a couple of quick prototypes I have this:

I need to make a neat way of attaching it other than strong rubber bands. I'll probably make a system that clips onto the groundglass somehow.
The corner indents indicate to me the limits to the stitched image in vertical and horizontal orientation with my chip (37x85mm and 49x73mm) on my STC.
Distortion is vastly less with my eye than through my P&S.

I thought it would be worth sharing with you guys.

 

[torger]

Super-cool! Good viewing solutions for the ground glass have been rare in tech cam land, and I've noted that viewing aids is a very personal thing. There's simply too few accessories to choose from in the main catalog to satisfy all tastes.

 

[tjv]

I'd really like to get a Hasselblad finder from an old Arc-Body to use on my Linhof Techno for composing–I'd still use the Linhof Studio 12x loupe for critical focus. What you've done looks brilliant, wish I had the skills to produce my own.