I have read thet ahe Heliopan is considerably sharper, but that is really good feedback about the Singh-ray... why spend $300+ on anything that softens the image. We do a lot of still work here too and I am hoping one of our pro shops locally might have a Heliopan I can demo... if so I will follow back up with a post if available.
I read a post from Phillip Bloom that the Heliopan was "tack sharp," (quite a bit sharper than the Singh-ray), but it did not discuss what that really meant.... whether it was 1080P from a 5D or stills at 5K+, I just don't know. So, Singh-ray is definitely out for me, if anyone has any experience with the Heliopan at 4K+ resolution (either stills or video), please chime in :-) Thanks!!!!