I have a 590nm conversion on a Sony A7. I did it because I wanted full frame *and* mirrorless advantages. I have two other conversions, a 720nm Nikon D70s and a 590nm D300. I like the color benefits of 590 (hence my choice for the A7) but love the 720 look also. I know, shoulda gone with a full spectrum. That said, can I run a 720nm filter over my 590 and get that look?