I have a mint Actar 24mm f/3.5 lens. It is a beautiful lens, specially designed to be used with the Cambo Actus view cameras. The lens is extremely well-corrected. It is susceptible to flare when aimed at the sun. I posted a review of this lens several months ago:
http://petapixel.com/2016/06/11/review-cambo-actar-24mm-f3-5-mirrorless-camera/ I finished the project that required the use of this lens. It works great with MFT and A7X cameras. It is the best wide angle option for the A7x/Actus combo.
B&H lists the lens for $1,695. I purchased the lens new from Capture Integration. I am asking $1,375 for the lens. It comes with the original box, paperwork, etc. I accept Paypal gift, so as not to incur the 3% charge. I will ship CONUS for $20.
The Actar performs much better than the Rokinon 24mm tilt-shift. Why? Because there is nothing mechanical other than the aperture. No helicoid focusing mechanism, no tilt mechanism, and no shift mechanism. I've used a Rokinon 24mm tilt-shift lens. It's not a bad lens, but the Actar is better--no moving optical elements. No doubt Cambo tests theses lenses on a bench to ensure quality.