which affordable lenses to choose for shooting raw video in crop mode with 7D?

[Brawl]

which affordable lenses to choose for shooting raw video in crop mode with 7D?
I'm searching for a 35 or 80mm full frame equivalent lens.
I'm also open to DIY solutions. Thanks a lot!

p.s.

I wish to understand better, if I buy 8mm full frame lens and I shoot raw video in crop mode on the 7D do I obtain 8mm x 3 x 1.6 = 38mm equivalent on a FF sensor?
I was searching for any aps-c "samyang 8mm raw video crop mode" and I couldn't find anything, can you help me to find one example please?  I wish to understand if the image will result distort.

thx!

[dfort]

I recently shot a test with that same 8mm lens on an APS-C sized Canon camera--though not a 7D.
http://magiclantern.fm/forum/index.php?topic=16054.msg161113#msg161113

There is still some curvature on the edges but it certainly doesn't look like a fisheye lens. Here's another shot with that lens in crop mode:

And here's a post showing video shot with a compact 8mm fisheye lens on an EOSM all in raw crop mode. The results on the 7D should be about the same.
http://magiclantern.fm/forum/index.php?topic=15961