Suffice it to say, these two filters are neutral density filters, which give you outstanding control to dampen down the incoming light. The Mor Slo knocks light down by 5 full stops, and when coupled with the Vari ND, you get an additional 8 stops of darkness. The Vari ND allows you to look through the view finder, compose your image, then to dial down from dark to black. Hugely useful. Otherwise, you would have to guess at your focus point, do a 30 second timed exposure and find the result was out of focus.
So, here are some blur-making shots, with one freeze-frame effect to show the difference.
All the best,
Chris Kiez