EL Pistoffo
Contributor
Maybe 3-4 inches (SRP site says 2-4). I kept it on on wide angle mode too 1080 -60 frames but I think I see some vignetting (overall not bad though, given gopros have limited close up/macro capability). I wish it was threaded though so you could experiment by adding more filters). I like this glass macro filter better than the acrylic ones.
3-4 inches is pretty good. I can only get to 5.5 inches with two +10 stacked. It may be worth getting. I'm about to experiment with a +20 and +10 stacked to see what I get but having a single lens is much easier to deal with.
As far as vignetting, I always try to go with Narrow FOV. As I'm setup right now, i'm using 58mm lenses. That extra width gives me no vignetting even while on Wide FOV. I may stick with getting a Marumi 58mm +10 and try combining it with others.